Geir Johnsen

About

Geir Johnsen is a professor in marine biology at the Department of Biology (NTNU), Prof II at University Centre on Svalbard (UNIS), and is one of the founding partners in a NTNU spin-off company Ecotone using new optical techniques for mapping and monitoring the marine environment. He is a key scientist in the Centre of excellence (CeO) "Autonomous Marine Operations and Systems (AMOS). Currently he is on a 1 year research stay at University of Hawaii at Manoa, Honululu working with spectral bioluminescence in different taxa and mapping and monitoring of coral reefs.

Research areas

Marine ecology and biodiversity
Bio-optics
Photosynthesis
Pigment chemotaxonomy
Underwater robotics and sensor development for in situ identification
Mapping and monitoring of bio-geo-chemical objects of interest in the marine environment

He has been an adviser for 47 MSc students and 17 PhD candidates. Currently, he advises 3 MSc students and 5 PhD candidates.

He has published more than 130 papers in international scientific journals and been a co-editor for the books:

"Ecosystem Barents Sea" (Tapir Academic Press)
"Phytoplankton pigments: Updates on Characterization, Chemotaxonomy and Applications in Oceanography" (Cambridge University Press, 2011).

Publications

2026

Summers, Natalie Maria; Bremnes, Jens Einar; Liu, Hongbo; Løvås, Håvard Snefjellå; Moreira Fragoso, Glaucia; Johnsen, Geir. (2026) Assessing Arctic under sea-ice light regimes and ice algal bio-optical properties using ROV-based hyperspectral imaging. Polar Biology
Academic article
Moreira Fragoso, Glaucia; Hama, Nalia; Snijder, Elisabeth; Aldridge, David; Borrero Santiago, Ana Rocio; Broch, Ole Jacob; Johnsen, Geir; Olsen, Yngvar; Hatlebakk, Maja Karoline Viddal. (2026) The influence of environmental factors and phytoplankton blooms on cyphonautes larvae abundance and bryozoan colony development at a kelp farm in central Norway. Marine Environmental Research
Academic article
Johnsen, Geir; Berge, Jørgen; Zolich, Artur; Mckee, David James Christopher; Cohen, Johnathan; Vogedes, Daniel Ludwig; Kopec, Tomasz Piotr. (2026) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2025). NIRD Research Data Archive
Data set

2025

Johnsen, Geir; Berge, Jørgen; Zolich, Artur; Mckee, David James Christopher; Cohen, Johnathan; Vogedes, Daniel Ludwig; Kopec, Tomasz Piotr. (2025) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2024). NIRD Research Data Archive
Data set
Johnsen, Geir; Berge, Jørgen; Zolich, Artur; Mckee, David James Christopher; Cohen, Johnathan; Vogedes, Daniel Ludwig; Kopec, Tomasz Piotr. (2025) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2023). NIRD Research Data Archive
Data set
Johnsen, Geir; Berge, Jørgen; Zolich, Artur; Mckee, David James Christopher; Cohen, Johnathan; Vogedes, Daniel Ludwig; Kopec, Tomasz Piotr. (2025) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2022). NIRD Research Data Archive
Data set
Johnsen, Geir; Berge, Jørgen; Zolich, Artur; Mckee, David James Christopher; Cohen, Johnathan; Vogedes, Daniel Ludwig; Kopec, Tomasz Piotr. (2025) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2021). NIRD Research Data Archive
Data set
Paiba Garcia, Laura Catherine; Johnsen, Geir; Perrin, Sam Wenaas; Bakken, Torkild. (2025) Open‐Source Marine Biodiversity Data Quality in the Norwegian Sea Spanning 149 Years: Knowledge Gaps in the Deep‐Sea Mining Opening Area. Ecology and Evolution
Academic article
Reigstad, Marit; Johnsen, Geir; Sundfjord, Arild. (2025) The Barents Sea system - Gateway to the changing Arctic. Fagbokforlaget
Anthology
Berge, Jørgen; Bakken, Torkild; Heggland, Kristin; Sneli, Jon-Arne; Ødegård, Øyvind; Ingulstad, Mats; Thun, Terje; Johnsen, Geir. (2025) Exploring Climate Change, Geopolitics, Marine Archeology, and Ecology in the Arctic Ocean Through Wood-Boring Bivalves. Oceanography
Academic article
Neves, Luiza S.; Smeby, Kristin; Broch, Ole Jacob; Johnsen, Geir; Ardelan, Murat van; Skjermo, Jorunn. (2025) Particulate and dissolved organic carbon losses in high latitude seaweed farms. Science of the Total Environment
Academic article
Jones, Alun; Utne, Ingrid Bouwer; Johnsen, Geir. (2025) Towards ecological integration into socio-technical risk assessment: A multidisciplinary system-theoretic approach. Ocean Engineering
Academic article
Günzel, Leonard Florian Tom; Osanen, Janina Emilia; Løvås, Håvard Snefjellå; Johnsen, Geir; Ortiz, Alberto García; Ludvigsen, Martin. (2025) Using Underwater Hyperspectral Imaging to Increase Feature Detection and Improve Under-Ice Navigation. IEEE Underwater Technology (UT)
Academic article

2024

Schartmüller, Bernhard; Mckee, David; Berge, Jørgen; Johnsen, Geir. (2024) Calibration verification of an underwater hyperspectral imaging push broom instrument to measure light in absolute units and field demonstration. Applied Optics
Academic article
Førde, Hedda; Grant, Stephen Denis; Viljanen, Martta; Majaneva, Sanna Kristiina; Johnsen, Geir. (2024) Glow and know – Evaluating the Potential of Spectral Bioluminescence as a Tool for Zooplankton Identification in situ. Norges teknisk-naturvitenskapelige universitet
Master thesis
Five, Taran; Majaneva, Sanna Kristiina; Viljanen, Martta; Grant, Stephen Denis; Johnsen, Geir. (2024) Studying Behavioral Responses to Bioluminescence in Zooplankton. Norges teknisk-naturvitenskapelige universitet
Master thesis
Moreira Fragoso, Glaucia; Dallolio, Alberto; Grant, Stephen Denis; Garrett, Joseph Landon; Ellingsen, Ingrid Helene; Johnsen, Geir; Johansen, Tor Arne. (2024) The Role of Rapid Changes in Weather on Phytoplankton Spring Bloom Dynamics Captured by an Autonomous Uncrewed Surface Vehicle. Earth and Space Science
Academic article
Berge, Jørgen; Johnsen, Geir; Last, Kim; Cohen, Jonathan H.; McKee, David. (2024) Light in polar regions.
Non-fiction chapter
Ingulstad, Mats; Bakken, Torkild; Ellefmo, Steinar Løve; Johnsen, Geir; Hagspiel, Verena. (2024) Villedende om hypotetiske havbunnsmineraler?. Dagens næringsliv
Commentary
Mo-Bjørkelund, Tore; Majaneva, Sanna Kristiina; Moreira Fragoso, Glaucia; Johnsen, Geir; Ludvigsen, Martin. (2024) Multi-vehicle adaptive 3D mapping for targeted ocean sampling. PLOS ONE
Academic article
Faltynkova, Andrea; Deschenes, Catherine; Zolich, Artur; Wagner, Martin; Johansen, Tor Arne; Johnsen, Geir. (2024) Use of an uncrewed surface vehicle and near infrared hyperspectral imaging for sampling and analysis of aquatic microplastics. Marine Pollution Bulletin
Academic article
Moreira Fragoso, Glaucia; Dallolio, Alberto; Grant, Stephen Denis; Garrett, Joseph Landon; Ellingsen, Ingrid Helene; Johnsen, Geir; Johansen, Tor Arne. (2024) The Role of Rapid Changes in Weather on Phytoplankton Spring Bloom Dynamics From Mid-Norway Using Multiple Observational Platforms. Journal of Geophysical Research (JGR): Oceans
Academic article
Liu, Hongbo; Summers, Natalie Maria; Chen, Yi-Chun; Løvås, Håvard Snefjellå; Johnsen, Geir; Koestner, Daniel Warren; Sætre, Camilla; Hamre, Børge. (2024) Pixelwise immersion factor calibration for underwater hyperspectral imaging instruments. Optics Express
Academic article
Overrein, Martin Molberg; Tinn, Phil; Aldridge, David; Johnsen, Geir; Moreira Fragoso, Glaucia. (2024) Biomass estimations of cultivated kelp using underwater RGB images from a mini-ROV and computer vision approaches. Frontiers in Marine Science
Academic article

2023

Schartmuller, Bernhard; Anderson, Philip; Mckee, David; Connan-McGinty, Stacey; Kopec, Tomasz Piotr; Daase, Malin Hildegard Elisabeth; Johnsen, Geir; Berge, Jørgen. (2023) Development and calibration of a high dynamic range and autonomous ocean-light instrument to measure sub-surface profiles in ice-covered waters. Applied Optics
Academic article
Williamson, David Roddan; Moreira Fragoso, Glaucia; Majaneva, Sanna Kristiina; Dallolio, Alberto; Halvorsen, Daniel Ørnes; Hasler, Oliver Kevin; Oudijk, Adriënne Esmeralda; Langer, Dennis David; Johansen, Tor Arne; Johnsen, Geir. (2023) Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography
Academic article
Summers, Natalie Maria; Moreira Fragoso, Glaucia; Johnsen, Geir. (2023) Photophysiologically active green, red, and brown macroalgae living in the Arctic Polar Night. Scientific Reports
Academic article
Deschenes, C; Zolich, Artur; Wagner, Martin; Johnsen, Geir; Johansen, Tor Arne; Faltynkova, Andrea. (2023) Unmanned vehicle and hyperspectral imager for a more rapid microplastics sampling and analysis. OCEANS
Academic article
oudijk, AE; Johansen, Tor Arne; Johnsen, Geir; Alver, Morten Omholt. (2023) Simulating Hyperspectral Datacubes for Ocean Color: A Foundation for Phytoplankton Recognition in Spectral Signatures. OCEANS
Academic article
Krohn-Pettersen, Gitte; Majaneva, Sanna Kristiina; Viljanen, Martta; Grant, Stephen Denis; Johnsen, Geir. (2023) Blinks in the dark - Detecting and characterizing flash kinetics of bioluminescence for in situ species recognition of zooplankton. Norges teknisk-naturvitenskapelige universitet
Master thesis
Svendsen, Thea; Majaneva, Sanna Kristiina; Majaneva, Markus; Båtnes, Anna Solvang; Johnsen, Geir. (2023) The usability of eDNA to identify and quantify zooplankton communities. Norges teknisk-naturvitenskapelige universitet
Master thesis
Grant, Stephen Denis; Johnsen, Geir; Mckee, David; Zolich, Artur Piotr; Cohen, Jonathan H.. (2023) Spectral and RGB analysis of the light climate and its ecological impacts using an all-sky camera system in the Arctic. Applied Optics
Academic article
Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa; Hop, Haakon; Renaud, Paul E.; Smedsrud, Lars Henrik; Stige, Leif Christian. (2023) Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene
Academic literature review
Bakken, Sivert; Luis, Kelly; Johnsen, Geir; Johansen, Tor Arne. (2023) Evaluating hyperspectral Secchi depth retrieval through hybrid modeling and regression. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Academic article
Bakken, Sivert; Henriksen, Marie Bøe; Birkeland, Roger; Langer, Dennis David; Oudijk, Adriënne Esmeralda; Berg, Simen; Pursley, Yeshi Jampel; Garrett, Joseph Landon; Gran-Jansen, Fredrik; Honoré-Livermore, Evelyn. (2023) HYPSO-1 CubeSat: First Images and In-Orbit Characterization. Remote Sensing
Academic article

2022

Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Moreira Fragoso, Glaucia; Berge, Jørgen. (2022) Underwater Hyperspectral Imaging of Arctic Macroalgal Habitats during the Polar Night Using a Novel Mini-ROV-UHI Portable System. Remote Sensing
Academic article
Johnsen, Geir; Aberle-Malzahn, Nicole; Fragoso, Glaucia; Thu, Maren. (2022) Phytoplankton spring bloom mapping in coastal areas using Autonomous Underwater Vehicle (AUV) and optical approaches. Norges teknisk-naturvitenskapelige universitet
Master thesis
Nøland, Annecken; Johnsen, Geir; Aberle-Malzahn, Nicole. (2022) Autonomous Underwater Vehicle (AUV) based study of zooplankton communities, using a silhouette camera and artificial intelligence. Norges teknisk-naturvitenskapelige universitet
Master thesis
Søreng, Marte Opsahl; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad; Gryte, Kristoffer. (2022) Mapping of Zostera habitat in the Sublittoral Zone using Underwater Hyperspectral Imaging and Unmanned Surface Vehicle. Norges teknisk-naturvitenskapelige universitet
Master thesis
Zolich, Artur Piotr; Faltynkova, Andrea; Johnsen, Geir; Johansen, Tor Arne. (2022) Portable Catamaran Drone - an uncrewed sampling vehicle for micro-plastics and aquaculture research.
Academic chapter
Mogstad, Aksel Alstad; Løvås, Håvard; Sture, Øystein; Johnsen, Geir; Ludvigsen, Martin. (2022) Remote Sensing of the Tautra Ridge: An Overview of the World’s Shallowest Cold-Water Coral Reefs. Frontiers in Marine Science
Academic article
Oudijk, Esmée; Hasler, Oliver Kevin; Øveraas, Henning; Marty, Sabine; Williamson, David Roddan; Svendsen, Torbjørn Karl; Berg, Simen; Birkeland, Roger; Halvorsen, Daniel Ørnes; Bakken, Sivert. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Academic article
Moreira Fragoso, Glaucia; Davies, Emlyn John; Fossum, Trygve Olav; Ullgren, Jenny; Majaneva, Sanna; Aberle-Malzahn, Nicole; Ludvigsen, Martin; Johnsen, Geir. (2022) Contrasting phytoplankton-zooplankton distributions observed through autonomous platforms, in-situ optical sensors and discrete sampling. PLOS ONE
Academic article
Marnor, Camilla Mult; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Mapping distribution patterns of brittle stars using ROV-based imaging. Norges teknisk-naturvitenskapelige universitet
Master thesis
Nevstad, Malin Bø; Johnsen, Geir; Bakken, Torkild; Larsen, Martin Kvisvik; Mogstad, Aksel Alstad. (2022) Use of different imaging systems for ROV-based mapping of complex benthic habitats. Norges teknisk-naturvitenskapelige universitet
Master thesis
Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir; Kopec, Tomasz Piotr; Porter, Marie; Mckee, David. (2022) Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems
Academic article
Bjerkvoll, Mikkel; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Aerial & Underwater Hyperspectral Imagery For Shallow Benthic Nature Type Mapping. Norges teknisk-naturvitenskapelige universitet
Master thesis
Dona, Angela; Evertsen, Jussi; Johnsen, Geir. (2022) The role of parapodia and lack of photoacclimation in kleptoplasts of the sacoglossan sea slug Plakobranchus ocellatus. Coral reefs
Academic article

2021

Ringvold, Halldis; Taite, Morag; Allcock, A. Louise; Vecchione, Michael; Péan, Michel; Sandulli, Roberto; Johnsen, Geir; Fjellheim, Arne; Bakke, Snorre; Sannæs, Hanne. (2021) In situ recordings of large gelatinous spheres from NE Atlantic, and the first genetic confirmation of egg mass of Illex coindetii (Vérany, 1839) (Cephalopoda, Mollusca). Scientific Reports
Academic article
Bazilchuk, Nancy Reney; Berge, Jørgen; Johnsen, Geir. (2021) Lysforurensning I Arktis kan ha ødelagt forskningsresultater. Gemini.no
Popular science article
Cardwell, CR; Berge, Jørgen; Johnsen, Geir. (2021) Arctic voyage shines light on some cold, hard truths. The Herald, UK
Popular science article
Bazilchuk, Nancy Reney; Stahl, Annette; Johnsen, Geir; Saad, Aya; Thu, Maren; Nøland, Annecken; Aberle-Malzahn, Nicole. (2021) Sporhunden som lukter mikroalger. Gemini.no
Popular science article
Snyder, Mike; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2021) “Into the dark” documentary by Mike Snyder following Jørgen Berge (UiT), Geir Johnsen (NTNU) and David McKee (Uni Strathclyde) during Polar Night marine ecology work.
Film
Faltynkova, Andrea; Johnsen, Geir; Wagner, Martin. (2021) Hyperspectral imaging as an emerging tool to analyze microplastics: A systematic review and recommendations for future development. Microplastics and Nanoplastics
Academic literature review
Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2021) Underwater Hyperspectral Imaging as a Tool for Benthic Habitat Mapping. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Horni, K; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin. (2021) Internasjonalt forskningsmiljø dykker i Mjøsa etter at Oppland Arbeiderblad skrev om forurensning. Oppland arbeiderblad
Popular science article
Ringvold, Halldis; Johnsen, Geir; Andersen, Tom. (2021) Studies on Echinodermata from the NE Atlantic Ocean - Spatial distribution and abundance of Asteroidea, including taxonomic and molecular studies on Crossaster and Henricia genera - Value-chain results, including test fishery, biology, market and nutritional analysis on Parastichopus tremulus (Holothuroidea) from the Norwegian coast. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Løvås, Håvard; Mogstad, Aksel Alstad; Sørensen, Asgeir Johan; Johnsen, Geir. (2021) A Methodology for Consistent Georegistration in Underwater Hyperspectral Imaging. IEEE Journal of Oceanic Engineering
Academic article
Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura; Johnsen, Geir; Berge, Jørgen. (2021) Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biology
Academic article
Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan H.; Mckee, David; Kopec, Tomasz Piotr; Vogedes, Daniel Ludwig; Berge, Jorgen. (2021) All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic. Applied Optics
Academic article
Bakken, Sivert; Johnsen, Geir; Johansen, Tor Arne. (2021) Analysis and Model Development of Direct Hyperspectral Chlorophyll-A Estimation for Remote Sensing Satellites. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Academic article
Geoffroy, Maxime; Langbehn, Tom Jasper; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Bris, Arnault Le; Fisher, Jonathan A. D.; Daase, Malin; Mckee, David; Cohen, Jonathan H.. (2021) Pelagic organisms avoid white, blue, and red artificial light from scientific instruments. Scientific Reports
Academic article

2020

Ramirez-Llodra, Eva; Hilário, Ana; Paulsen, Emil; Costa, Carolina; Bakken, Torkild; Johnsen, Geir; Rapp, Hans Tore. (2020) Benthic Communities on the Mohn’s Treasure Mound: Implications for Management of Seabed Mining in the Arctic Mid-Ocean Ridge. Frontiers in Marine Science
Academic article
Moreira Fragoso, Glaucia; Johnsen, Geir; Chauton, Matilde Skogen; Cottier, Finlo Robert; Ellingsen, Ingrid H.. (2020) Phytoplankton community succession and dynamics using optical approaches. Continental Shelf Research
Academic article
Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.; Johnsen, Geir; Mckee, David; Kostakis, Ina; Renaud, Paul Eric. (2020) Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth. Communications Biology
Academic article
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Introduction.
Introduction in anthology
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr. (2020) Light in the Polar Night.
Academic chapter
Berge, Jørgen; Johnsen, Geir. (2020) Polar Night exhibition in Karelia (Petrozavodsk, Russia): 03.03 – 03.04.2020.
Exhibition
Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2020) Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots. Remote Sensing
Academic article
Johnsen, Geir; Leu, Eva; Gradinger, Rolf. (2020) Marine Micro- and Macroalgae in the Polar Night.
Academic chapter
Berge, Jørgen; Johnsen, Geir. (2020) Life and Light at the Dead of Night.
Academic chapter
Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H.. (2020) Operative Habitat Mapping and Monitoring in the Polar Night.
Academic chapter
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Polar night marine ecology - life and light in the dead of night. Springer
Anthology
Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole; Ludvigsen, Martin; Johnsen, Geir; Sousa, João; Rajan, Kanna. (2020) Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer. Oceanography
Academic article

2019

Kauko, Hanna Maria; Pavlov, Alexey; Johnsen, Geir; Granskog, Mats; Peeken, Ilka; Assmy, Philipp. (2019) Photoacclimation state of an Arctic underice phytoplankton bloom. Journal of Geophysical Research (JGR): Oceans
Academic article
Bazilchuk, Nancy Reney; Fossum, Trygve Olav; Moreira Fragoso, Glaucia; Ludvigsen, Martin; Johnsen, Geir. (2019) Smart undervannsrobot leter etter plankton. Av N Bazilchuk. Forskning.no. Angående NTNU Entice prosjekt publisert i Science Robotics. Forskning.no
Popular science article
Pavlov, Alexey K.; Leu, Eva; Hanelt, Dieter; Bartsch, Inka; Karsten, Ulf; Hudson, Stephen; Gallet, Jean-Charles; Cottier, Finlo Robert; Cohen, Jonathan H.; Berge, Jørgen. (2019) The Underwater Light Climate in Kongsfjorden and Its Ecological Implications.
Academic chapter
Moreira Fragoso, Glaucia; Davies, Emlyn John; Ellingsen, Ingrid H.; Chauton, Matilde Skogen; Fossum, Trygve Olav; Ludvigsen, Martin; Steinhovden, Kristine; Rajan, Kanna; Johnsen, Geir. (2019) Physical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspot. Progress in Oceanography
Academic article
Mogstad, Aksel Alstad; Johnsen, Geir; Ludvigsen, Martin. (2019) Shallow-Water Habitat Mapping using Underwater Hyperspectral Imaging from an Unmanned Surface Vehicle: A Pilot Study. Remote Sensing
Academic article
Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2019) Sea surface microlayer and elemental composition in phaeo-, chloro-, and rhodophytes in winter and spring. Journal of Phycology
Academic article
Fossum, Trygve Olav; Moreira Fragoso, Glaucia; Davies, Emlyn John; Ullgren, Jenny; Mendes, Renato; Johnsen, Geir; Ellingsen, Ingrid H.; Eidsvik, Jo; Ludvigsen, Martin; Rajan, Kanna. (2019) Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Science robotics
Academic article
Graham, Lisa Kristine Hernandez; Johnsen, Geir; Christensen-Dalsgaard, Signe. (2019) A pilot study assessing drones for mapping and monitoring of European shags. Norges teknisk-naturvitenskapelige universitet
Master thesis
Moreira Fragoso, Glaucia; Poulton, Alex James; Pratt, Nicola Jane; Johnsen, Geir; Purdie, Duncan Alastair. (2019) Trait-based analysis of subpolar North Atlantic phytoplankton and plastidic ciliate communities using automated flow cytometer. Limnology and Oceanography
Academic article

2018

Kauko, Hanna Maria; Johnsen, Geir; Assmy, Phillipp. (2018) Light response and acclimation of macroalgae in a changing Arctic. NTNU
Doctoral thesis
Strømsholm, Jørgen; Johnsen, Geir; Ludvigsen, Martin. (2018) Eyes beneath the surface - using a miniROV to reveal the habitat and dietary choices of the European shag. Norges teknisk-naturvitenskapelige universitet
Master thesis
Ødegård, Øyvind; Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging: a new tool for marine archaeology. Applied Optics
Academic article
Fjærtoft, Kaja Lønne; Bakken, Torkild; Johnsen, Geir; Ludvigsen, Martin. (2018) Macroalgal detritus: Physical variables and impacts on the benthic macrofaunal community. Norges teknisk-naturvitenskapelige universitet
Master thesis
Dumke, Ines; Purser, Autun; Marcon, Yann; Nornes, Stein Melvær; Johnsen, Geir; Ludvigsen, Martin; Søreide, Fredrik. (2018) Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports
Academic article
Kauko, Hanna Maria; Olsen, Lasse Mork; Duarte, Pedro; Peeken, Ilka; Granskog, Mats A.; Johnsen, Geir; Fernández-Méndez, Mar; Pavlov, Alexey; Mundy, Christopher John; Assmy, Philipp. (2018) Algal colonization of young arctic sea ice in spring. Frontiers in Marine Science
Academic article
Johnsen, Geir; Norli, Marit; Moline, Mark A.; Robbins, Ian; von Quillfeldt, Cecilie; Sørensen, Kai; Cottier, Finlo Robert; Berge, Jørgen. (2018) The advective origin of an under-ice spring bloom in the Arctic Ocean using multiple observational platforms. Polar Biology
Academic article
Dumke, Ines; Nornes, Stein Melvær; Purser, Autun; Marcon, Yann; Ludvigsen, Martin; Ellefmo, Steinar Løve; Johnsen, Geir; Søreide, Fredrik. (2018) First hyperspectral imaging survey of the deep seafloor: High-resolution mapping of manganese nodules. Remote Sensing of Environment
Academic article
Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin; Hansen, Roy Edgar; Maarleveld, Thijs. (2018) Towards Autonomous Operations and Systems in Marine Archaeology. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Zolich, Artur Piotr; Torre, Pedro R. De La; Rodwell, Shane; Geoffroy, Maxime; Johnsen, Geir; Berge, Jørgen. (2018) An ice-tethered buoy for fish and plankton research.
Academic chapter
Fossum, Trygve Olav; Eidsvik, Jo; Ellingsen, Ingrid H.; Alver, Morten; Moreira Fragoso, Glaucia; Johnsen, Geir; Mendes, Renato; Ludvigsen, Martin; Rajan, Kanna. (2018) Information-driven robotic sampling in the coastal ocean. Journal of Field Robotics (JFR)
Academic article
Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert; Mogstad, Aksel Alstad; Zolich, Artur Piotr; Last, Kim. (2018) Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic. Polar Biology
Academic article
Gabrielsen, Tove M.; Johnsen, Geir. (2018) Skogen på Svalbard. Svalbardposten
Popular science article
Nornes, Stein Melvær; Sørensen, Asgeir Johan; Ludvigsen, Martin; Johnsen, Geir; Schjølberg, Ingrid; Ånonsen, Kjetil Bergh. (2018) Guidance and Control of Marine Robotics for Ocean Mapping and Monitoring. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Dumke, Ines; Ludvigsen, Martin; Ellefmo, Steinar Løve; Søreide, Fredrik; Johnsen, Geir; Murton, Bramley J.. (2018) Underwater Hyperspectral Imaging Using a Stationary Platform in the Trans-Atlantic Geotraverse Hydrothermal Field. IEEE Transactions on Geoscience and Remote Sensing
Academic article
Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; Torre, Pedro R. De La; Nornes, Stein Melvær; Singh, Hanumant; Sørensen, Asgeir Johan; Daase, Malin; Johnsen, Geir. (2018) Use of an autonomous surface vehicle reveals small-scale diel vertical migrations of zooplankton and susceptibility to light pollution under low solar irradiance. Science Advances
Academic article
Moreira Fragoso, Glaucia; Poulton, Alex J.; Yashayaev, Igor M.; Head, Erica J.H.; Johnsen, Geir; Purdie, Duncan A.. (2018) Diatom biogeography from the Labrador Sea revealed through a trait-based approach. Frontiers in Marine Science
Academic article
Liefmann, Stephanie; Järnegren, Johanna; Johnsen, Geir; Murray, Fiona. (2018) Eco-physiological responses of cold-water soft corals to anthropogenic sedimentation and particle shape. Journal of Experimental Marine Biology and Ecology
Academic article

2017

Kauko, Hanna Maria; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C.J.; Duarte, Pedro; Fernández-Méndez, Mar; Olsen, Lasse Mork; Hudson, Stephen R.; Johnsen, Geir. (2017) Windows in Arctic sea ice: light transmission and ice algae in a refrozen lead. Journal of Geophysical Research (JGR): Biogeosciences
Academic article
Alvsvåg, Dora Marie; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Berge, Jørgen. (2017) Mapping of a seagrass habitat in Hopavågen, Sør-Trøndelag, with the use of an Autonomous Surface Vehicle combined with optical techniques. Norges teknisk-naturvitenskapelige universitet
Master thesis
Mynors, Julie; Johnsen, Geir; Wernand, Marcel; Volent, Zsolt. (2017) Ocean Colour and Phytoplankton Dynamics - An examination of the Forel-Ule scale in a modern context. Norges teknisk-naturvitenskapelige universitet
Master thesis
Mogstad, Aksel Alstad; Johnsen, Geir. (2017) Spectral characteristics of coralline algae: a multi-instrumental approach, with emphasis on underwater hyperspectral imaging. Applied Optics
Academic article
Berge, Jørgen; Johnsen, Geir; Tandberg, Anne helene. (2017) Polar night - Life and light in the dead of night.
Exhibition
Kamilla, Sporsheim; Sporsheim, Kamilla; Johnsen, Geir; Reitan, Kjell Inge; Evertsen, Antii Jussi. (2017) Astaxanthin as a biomarker for fish feed loading in the marine ecosystem. Norges teknisk-naturvitenskapelige universitet
Master thesis
Kjeken, John; Johnsen, Geir; Ludvigsen, Martin; Thorsnes, Terje; Lågstad, Petter Arthur. (2017) The growth of benthic organisms in a dumping ground for military bombs and munitions. Norges teknisk-naturvitenskapelige universitet
Master thesis
Johnsen, Geir; Sandbu, Marthe; Assmy, Philipp. (2017) High Arctic Sea-Ice Algae - The Use of Rapid Light Curves to Assess Photosynthetic Performance of Different Ice-Algal Communities. Norges teknisk-naturvitenskapelige universitet
Master thesis
Paulsen, Emil; Bakken, Torkild; Ramirez-Llodra, Eva; Johnsen, Geir. (2017) Community structure and biodiversity of the benthic megafauna at the inactive hydrothermal site Mohn's Treasure, on the Mohn's Ridge, Arctic Mid-Ocean Ridge (AMOR). Norges teknisk-naturvitenskapelige universitet
Master thesis
Ostaszewska, Kaja; Balazy, Piotr; Berge, Jørgen; Johnsen, Geir; Staven, Robert. (2017) Seabirds during Arctic Polar Night: underwater observations from Svalbard archipelago, Norway. Waterbirds (De Leon Springs, Fla.)
Academic article
Andersson, Ingvild Henriette Kristin; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin. (2017) Bio-optical diversity on cold water coral habitats. Norges teknisk-naturvitenskapelige universitet
Master thesis
Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John; Olsen, Lasse Mork; Kauko, Hanna M.; Bailey, Allison; Chierici, Melissa. (2017) Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic. Scientific Reports
Academic article

2016

Donahue, Michelle; Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) The age of humans - living in the anthropocene - "Termites of the sea" found munching wood near Arctic shipwrecks. Smithsonian
Popular science article
Førde, Henny; Forbord, Silje; Handå, Aleksander; Fossberg, Julia; Arff, Johanne; Johnsen, Geir; Reitan, Kjell Inge. (2016) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. Journal of Applied Phycology
Academic article
Gätzschmann, Per; Hårsaker, Karstein; Johnsen, Geir; Leite, Stein Roar; Pedersen, Solbjørg; Sørumgård, Marit. (2016) Nye oppdagelser i polarnatta - video.
Exhibition
Berge, Jørgen; Renaud, Paul E.; Johnsen, Geir; Darnis, Gerald; Geoffroy, Maxime; Daase, Malin; Kwasniewski, S; Draganska, K; Cottier, Finlo Robert; Falk-Petersen, Stig. (2016) I grenselandet (mellom Tull og Thule). Svalbardposten
Popular science article
Haugstad, Tor; Erdal, Ivar; Johnsen, Geir; Sørensen, Asgeir Johan; Fjærvik, Nils. (2016) Gründerne mener dette kameraet kan bli det nye ekkoloddet – Ecotone er kandidat til TU Tech Award. Teknisk Ukeblad
Popular science article
Liefmann, Stephanie; Johnsen, Geir; Järnegren, Johanna. (2016) Eco-physiological responses of cold-water corals to anthropogenic sedimentation and particle shape. Norges teknisk-naturvitenskapelige universitet
Master thesis
Aarskog, Karine Nigar; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2016) Et stort løft for arktisk forskning (NTNU & UiT). Universitetet i Tromsø
Professional article
Haudemann-Andersen, Jørn; Lystad, M S; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2016) Blå lys i det kalde dyp. NRK Trøndelag, Nyheter
Popular science article
Bazilchuk, Nancy Reney; Leite, Stein Roar; Johnsen, Geir; Kjeken, John; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2016) Bomber og buss på havbunnen. Gemini
Popular science article
Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Sørumgård, Marit; Sandbakk, Elin; Johnsen, Tobias Kvendseth. (2016) Polarnatt/Polar Night - ny utstilling med nyheter fra 2015-2016.
Exhibition
Johnsen, Geir. (2016) Yrende liv i Isfjorden. Svalbardposten
Popular science article
Krüger, Frida Jørstad; Johnsen, Geir; Kjeken, John; Ludvigsen, Martin. (2016) Gammel buss ble korallrev. NRK Viten
Popular science article
Lervik, Frank; Johnsen, Geir; Ludvigsen, Martin; Kjeken, John. (2016) Det ligger flere busser der. Adresseavisen
Popular science article
Bjørgan, Espen Halvorsen; Johnsen, Geir; Kjeken, Jon; Ludvigsen, Martin. (2016) Fant buss på 600 m dybde. Adresseavisen
Popular science article
Berge, Jørgen; Falk-Petersen, Stig; Renaud, Paul E.; Daase, Malin; Geoffroy, Maxime; Johnsen, Geir. (2016) En reise mot Ultima Thule. Svalbardposten
Popular science article
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Ludvigsen, Martin; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Mørkets fyrster, varulver og Indiana Jones. Gemini
Popular science article
Kokkegård, Hanne; Johnsen, Geir; Ludvigsen, Martin; Torre, Pedro De La. (2016) Vitenskab - Bomber fra 2 verdenskrig danner koralrev på 600 m dybde. Danmarks radio
Popular science article
Håpnes, Sverre Julian; Johnsen, Geir; Ludvigsen, Martin; Lågstad, Petter Arthur. (2016) Mapping of demersal fish and benthos by AUV equipped with optical and acoustic imagers at 600 m depth in Trondheimsfjorden. NTNU MSc
Master thesis
Berge, Jørgen; Johnsen, Geir. (2016) Mørkets fyrster med påskrudd lys. Svalbardposten
Popular science article
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Mark spiser opp vrak på havbunnen. Fiskaren
Popular science article
Bondø, Tor-Hartvig; Johnsen, Geir; Berge, Jørgen. (2016) Fant yrende liv i polarnatta. VG : Verdens gang
Popular science article
Johnsen, Geir; Ludvigsen, Martin; Sørensen, Asgeir Johan; Aas, Lars Martin Sandvik. (2016) The use of underwater hyperspectral imaging deployed on remotely operated vehicle – methods and applications. IFAC-PapersOnLine
Academic article
Jakobsen, June; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Karlsen, Svein. (2016) The Tautra Cold-Water Coral Reef - Mapping and describing the biodiversity of a cold-water coral reef ecosystem in the Trondheimsfjord by use of multi-beam echo sounding and video mounted on a remotely operated vehicle. Norges teknisk-naturvitenskapelige universitet
Master thesis
Cronin, Heather; Cohen, Jonathan H.; Berge, Jørgen; Johnsen, Geir; Moline, Mark A.. (2016) Bioluminescence as an ecological factor during high Arctic polar night. Scientific Reports
Academic article
Berge, Jørgen; Geoffroy, Maxime; Johnsen, Geir; Cottier, Finlo Robert; Bluhm, Bodil; Vogedes, Daniel Ludwig. (2016) Ice-tethered observational platforms in the Arctic Ocean pack ice. IFAC-PapersOnLine
Academic article

2015

Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig; Renaud, Paul; Leu, Eva; Grenvald, Julie Cornelius; Cottier, Finlo. (2015) Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?. PLOS ONE
Academic article
Aarekol, Lena; Johnsen, Geir; Berge, Jørgen. (2015) Polarnatt. Liv og lys i mulm og mørke Polarnighth. Life and death in dead of night.
Exhibition
Tandberg, Anne Helene S.; Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) POLARNATT - liv og lyst i mulm og mørke.
Exhibition
Nilssen, Ingunn; Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Moline, Mark A.; Berge, Jørgen. (2015) Integrated environmental mapping and monitoring, a methodological approach to optimise knowledge gathering and sampling strategy. Marine Pollution Bulletin
Academic article
Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.; Johnsen, Geir; Seuthe, Lena; Weslawski, Jan Marcin; Leu, Eva. (2015) In the dark: a review of ecosystem processes during the Arctic polar night. Progress in Oceanography
Academic article
Berge, Jørgen; Daase, Malin; Renaud, Paul; Ambrose, William G. Jr.; Darnis, Gérald; Last, Kim S; Leu, Eva; Cohen, Jonathan H.; Johnsen, Geir; Moline, Mark A.. (2015) Unexpected levels of biological activity during the polar night offer new perspectives on a warming Arctic. Current Biology
Academic article
Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur; Ødegård, Øyvind; Candeloro, Mauro; Nornes, Stein Melvær; Malmquist, Christian. (2015) Underwater vehicles for environmental management in coastal areas.
Academic chapter
Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) Life and light in the dead of night.
Exhibition
Nilssen, Ingunn; Santos, Francisco Dos; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo M.; Eide, Ingvar; Figueiredo, Marcia AO; Johnsen, Geir; Johnsen, Ståle. (2015) Assessing the potential impact of water-based drill cuttings on deep water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
Academic article
Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan; Nilssen, Ingunn. (2015) Enabling technology for Arctic research. Pan European Networks: Science and Techology Magazine
Academic literature review
Nilssen, Ingunn; dos, Francisco Santos; Coutinho, Ricardo; Gomes, Natalia; Montenegro, Marcelo Cabral; Eide, Ingvar; Figueiredo, Marcia; Johnsen, Geir; Johnsen, Ståle. (2015) Assessing the potential impact of water-based drill cuttings on deep-water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
Academic article
Rodriguez, Francisco; Garrido, J.L.; Sabrino, C; Johnsen, Geir; Riobo, P; Franco, J; Aamot, Inga; Ramilo, I; Sanz, N; Kremp, Anke. (2015) Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae). Environmental Microbiology
Academic article

2014

Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Valle, Kristin Collier. (2014) Photoacclimation mechanismsand light responses in marine micro- and macroalgae. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2014) Elemental Composition in various Marine Brown, Green and Red Macroalgae with respect to Season and Tissue-Age. Norges teknisk-naturvitenskapelige universitet
Master thesis
Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik; Moline, Mark A.. (2014) Managing data from multiple sensors in an interdisciplinary research cruise.
Academic chapter
Lund, Lene; Johnsen, Geir; Bakken, Torkild; Gabrielsen, Tove. (2014) Morphological Diversity in Laminaria digitata: -different Species or different Phenotypes?. Norges teknisk-naturvitenskapelige universitet
Master thesis
Cohen, Jonathan; Cronin, Heather; Moline, Mark A.; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Are krill eyes useful in the high Arctic polar night?. Ocean Optics
Conference abstract
Aamot, Inga; Pokrzywinski, Kaytee; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan. (2014) Light Climate and Status of the Photosynthetic Machinery in Macroalgae in the Polar Night. Ocean Optics
Conference abstract
Hansen, Ingrid; Pettersen, Ragnhild; Beuchel, Frank; Cochrane, Sabine; Frantzen, marianne; Ekehaug, Stefan; Erdal, Ivar; Johnsen, Geir; Camus, Lionel. (2014) Underwater hyperspectral imaging (UHI) for environmental mapping and monitoring of seabed habitats. Ocean Optics
Conference abstract
Nilssen, Ingunn; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen; Nornes, Stein Melvær; Norgren, Petter; Vieweg, Ireen. (2014) Integrated environmental monitoring; a methodological approach to optimise knowledge gathering and sampling strategy. Ocean Optics
Conference abstract
Johnsen, Geir; Ekehaug, Stefan; Hansen, Ingrid; Sørensen, Asgeir Johan. (2014) The use of underwater hyperspectral imaging deployed on remotely operated vehicles to identify, map and monitor bio-geo-chemical objects of interest. Ocean Optics
Conference abstract
Nornes, Stein Melvær; Candeloro, Mauro; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Photomosaic camera as simultaneous data collector and navigation aid on unmanned underwater vehicles. Ocean Optics
Conference abstract
Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Lågstad, Petter Arthur; Ødegård, Øyvind. (2014) Scientific Operations Combining ROV and AUV in the Trondheim Fjord. Marine Technology Society journal
Academic article
Kvernvik, Ane Cecilie; Johnsen, Geir; Aamot, Inga. (2014) How Lamina Age Influence Photosynthetic Response to Light Variations in Saccharina latissima. Norges teknisk-naturvitenskapelige universitet
Master thesis
Eldevik, Tor; Reigstad, Marit; Falck, Eva; Gerland, Sebastian; Jentoft, Sissel; Johnsen, Geir; Lindstrøm, Ulf; Rasmussen, Tine Lander; Røed, Lars Petter; Wassmann, Paul. (2014) Arven efter Nansen. Forskningsplan for det sentrale og nordlige Barentshavet. UiT Norges arktiske universitet
Research report
Berge, Jørgen; Cottier, Finlo; Varpe, Øystein; Renaud, Paul; Falk-Petersen, Stig; Kwasniewski, Sawomir; Griffiths, Colin; Søreide, Janne; Johnsen, Geir; Aubert, Anais. (2014) Arctic complexity: A case study on diel vertical migration of zooplankton. Journal of Plankton Research
Academic article
Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Glowing in the dark: Discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
Academic article
Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Erratum to: Glowing in the dark: discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
Corrigendum
Valle, Kristin Collier; Johnsen, Geir; Bones, Atle M. (2014) Photoacclimation mechanisms and light responses in marine micro- and macroalgae. NTNU
Doctoral thesis
Hallerud, Charlotte; Johnsen, Geir; Aamot, Inga. (2014) Pigment Composition of Macroalgae from a Norwegian Kelp Forest. Norges teknisk-naturvitenskapelige universitet
Master thesis
Hatlebakk, Maja; Johnsen, Geir; Søreide, Janne. (2014) Effect of lipids and fatty acid composition on success of reproduction in Calanus glacialis. NTNU
Master thesis
Kjerstad, Ingrid; Johnsen, Geir; Sørensen, Asgeir Johan; Bakken, Torkild. (2014) Underwater Imaging and the effect of Inherent Optical Properties on image quality. Norges teknisk-naturvitenskapelige universitet
Master thesis
Førde, Henny; Reitan, Kjell Inge; Johnsen, Geir. (2014) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. NTNU
Master thesis
Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir; Brembu, Tore; Bones, Atle M.. (2014) System responses to equal doses of photosynthetically usable radiation of blue, green, and red light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Academic article

2013

Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Nymark, Marianne. (2013) Light responses in the marine diatom Phaeodactylum tricornutum. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Hovland, Erlend Kjeldsberg; Dierssen, Heidi; Ferreira, Ana Sofia; Johnsen, Geir. (2013) Dynamics regulating major trends in Barents Sea temperatures and subsequent effect on remotely sensed particulate inorganic carbon. Marine Ecology Progress Series
Academic article
Pettersen, Ragnhild; Johnsen, Geir; Bruheim, Per; Andreassen, Trygve. (2013) Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms. Organisms Diversity & Evolution
Academic article
Berge, Jørgen; Johnsen, Geir; Falk-Pettersen, Stig. (2013) Mørkets hemmeligheter. Svalbardposten
Popular science article
Johnsen, Geir; Volent, Zsolt; Dierssen, Heidi; Pettersen, Ragnhild; Ardelan, Murat Van; Søreide, Fredrik; Fearns, Peter; Ludvigsen, Martin; Moline, Mark A.. (2013) Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties.
Academic chapter
Ludvigsen, Martin; Johnsen, Geir; Lågstad, Petter Arthur; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord.
Academic chapter
Pettersen, Ragnhild; Johnsen, Geir. (2013) Identification of Marine Organisms using Chemotaxonomy and Hyperspectral Imaging. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Båtnes, Anna Solvang; Miljeteig, Cecilie; Berge, Jørgen; Greenacre, Michael; Johnsen, Geir. (2013) Quantifying the light sensitivity of Calanus spp. during the polar night: potential for orchestrated migrations conducted by ambient light from the sun, moon, or aurora borealis. Polar Biology
Academic article
Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan. (2013) The use of side scan and synthetic aperture sonar mounted on autonomous underwater vehicles for biological habitat mapping. NTNU
Master thesis
Ingrid, Hansen; Johnsen, Geir; Sørensen, Asgeir Johan. (2013) Optical Mapping of Cold-water Corals in Trondheimsfjorden and Svalbard. NTNU
Master thesis
Båtnes, Anna Solvang; Johnsen, Geir. (2013) Light in the dark – the role of irradiance in the high Arctic marine ecosystem during polar night. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir; Bones, Atle M.; Brembu, Tore. (2013) Molecular and photosynthetic responses to prolonged darkness and subsequent acclimation to re-illumination in the diatom Phaeodactylum tricornutum. PLOS ONE
Academic article

2012

Fremstedal, Ane Sofia Viset; Bruheim, Per; Sletta, Håvard; Johnsen, Geir. (2012) Utvikling og optimalisering av protokoll for massespektrometrisk metabolsk profilering av adherente humane celler. Norges teknisk-naturvitenskapelige universitet
Master thesis
Belseth, Elen; Johnsen, Geir; Berge, Jørgen. (2012) Eco-physiology of the Arctic kelp Laminaria solidungula. NTNU Master thesis
Master thesis
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Sakshaug, Egil; Folkestad, Are. (2012) Bio-optics and Ecology in Emiliania huxleyi Blooms: Field and Remote Sensing Studies in Norwegian Waters. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Gabrielsen, Tove M; von Quillfeldt, Cecilie; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden. Svalbardposten
Commentary
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2012) Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography. Cambridge University Press
Anthology
Elde, Anette; Pettersen, Ragnhild; Bruheim, Per; Järnegren, Johanna; Johnsen, Geir. (2012) Pigmentation and Spectral Absorbance Signatures in Deep-Water Corals from the Trondheimsfjord, Norway. Marine Drugs
Academic article
Hovland, Erlend Kjeldsberg; Hancke, Kasper; Alver, Morten; Drinkwater, Kennneth F.; Høkedal, Jo; Johnsen, Geir; Moline, Mark A.; Sakshaug, Egil. (2012) Optical impact of an Emiliania huxleyi bloom in the frontal region of the Barents Sea. Journal of Marine Systems
Academic article
Hancke, Kasper; Hovland, Erlend Kjeldsberg; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark A.; Sakshaug, Egil. (2012) Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance. Journal of Marine Systems
Academic article
Berge, Jørgen; Båtnes, Anna Solvang; Johnsen, Geir; Blackwell, Susan; Moline, Mark A.. (2012) Bioluminescence in the high Arctic during the polar night. Marine Biology
Academic article

2011

Volent, Zsolt; Johnsen, Geir; Hovland, Erlend Kjeldsberg; Folkestad, Are; Olsen, Lasse Mork; Tangen, Karl; Sørensen, Kai. (2011) Improved monitoring of phytoplankton bloom dynamics in a Norwegian fjord by integrating satellite data, pigment analysis, and Ferrybox data with a coastal observation network. Journal of Applied Remote Sensing
Academic article
Johnsen, Geir; Moline, Mark; Pettersson, Lasse H.; Pinckney, J. L.; Pozdnyakov, Dmitry; Egeland, Einar Skarstad; Schofield, O. M.. (2011) Optical monitoring of phytoplankton bloom pigment signatures.
Academic chapter
Bjørdalsbakke, Lise Kristin; Johnsen, Geir; Bakken, Torkild; Berge, Jørgen. (2011) Population structure, parasitism and prey preference in Sclerocrangon boreas and S. ferox, Svalbard. Norges teknisk-naturvitenskapelige universitet
Master thesis
Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2011) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
Academic article
Pettersen, Ragnhild; Johnsen, Geir; Berge, Jørgen; Hovland, Erlend Kjeldsberg. (2011) Phytoplankton chemotaxonomy in waters around the Svalbard archipelago reveals high amounts of Chl b and presence of gyroxanthin-diester. Polar Biology
Academic article
Jouenne, Fabien; Eikrem, Wenche; Gall, F Le; Marie, Dominique; Johnsen, Geir; Vaulot, Daniel. (2011) Prasinoderma singularis sp. nov. (Prasinophyceae, Chlorophyta), a Solitary Coccoid Prasinophyte from the South-East Pacific Ocean. Protist
Academic article
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Preface.
Introduction in anthology
Llewellyn, Carole A.; Roy, Suzanne; Johnsen, Geir; Egeland, Einar Skarstad; Chauton, Matilde; Hallegraeff, Gustaff; Lohr, Martin; Oster, Ulrike; Porra, Robert J.; Scheer, Hugo. (2011) Perspectives on future directions.
Academic chapter
Andersen, Hanne Kile; Johnsen, Geir; Bakken, Torkild. (2011) Gastropods Associated with Laminaria hyperborea and Saccorhiza polyschides in a Norwegian Kelp Forest: Comparison of Sampling and In Situ Imaging Techniques. Norges teknisk-naturvitenskapelige universitet
Master thesis
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press
Anthology
Brunet, Christophe; Johnsen, Geir; Lavaud, Johan; Roy, Suzanne. (2011) Pigments and photoacclimation processes.
Academic chapter
Johnsen, Geir; Bricaud, Annick; Nelson, Norman; Prézelin, Barbara; Bidigare, Robert. (2011) In vivo bio-optical properties of phytoplankton pigments.
Academic chapter

2010

Aamot, Inga; Berge, Jørgen; Hancke, Kasper; Johnsen, Geir; Moline, Mark; Schofield, Oscar. (2010) NORUS - Technology Development for Marine Monitoring and Ocean Observation:An North America-Norway educational program. http://ipy-osc.no/abstract/
Conference abstract
Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2010) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
Academic article
Johnsen, Geir; Søreide, Fredrik. (2010) Underwater hyperspectral imaging of marine mineral deposits. Underwater Mining meeting Institute (UMI)
Conference abstract

2009

Johnsen, Geir; Nepstad, Ina. (2009) Cloning and characterisation of interleukin-6 and interleukin-11b in Atlantic halibut (Hippoglossus hippoglossus). NTNU, Institutt for biologi
Master thesis
Sakshaug, E.; Johnsen, Geir; Kristiansen, Svein; Quillfeldt, C.v.; Rey, F.; Slagstad, D.; Thingstad, F.. (2009) Phytoplankton and primary production.
Academic chapter
Johnsen, Geir; Volent, Z; Sakshaug, E.; Sigernes, Fred; Pettersson, L.H.. (2009) Remote sensing in the Barents Sea.
Academic chapter
Evertsen, Jussi; Johnsen, Geir. (2009) In vivo and in vitro differences in chloroplast functionality in the two north Atlantic sacoglossans (Gastropoda, Opisthobranchia) Placida dendritica and Elysia viridis. Marine Biology
Academic article
Sakshaug, E.; Johnsen, Geir; Volent, Z. (2009) Light.
Academic chapter
Berge, Jørgen; Lønne, Ole Jørgen; Renaud, Paul; Johnsen, Geir; Gulliksen, Bjørn; Varpe, Øystein; Nygård, Henrik. (2009) Polartorsken - vil den bli utkonkurrert av sørlige fiskearter?. Svalbardposten
Popular science article
Berge, Jørgen; Cottier, Finlo; Last, Kim S.; Varpe, Øystein; Leu, Eva; Søreide, Janne; Eiane, Ketil; Falk-Petersen, S.; Willis, Kate; Nygård, Henrik. (2009) Diel vertical migration of Arctic zooplankton during the polar night. Biology Letters
Academic article
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit M.. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag
Non-fiction monograph
Quillfeldt, Cecilie H. von; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik. (2009) Ice algae.
Academic chapter
Sakshaug, E.; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag
Textbook
Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Winge, Per; Hancke, Kasper; Andresen, Kjersti; Johnsen, Geir; Bones, Atle M.. (2009) An integrated analysis of molecular acclimation to high light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Academic article
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag
Anthology
Quillfeldt, C.v.; Hegseth, E.N.; Johnsen, Geir; Sakshaug, E.; Syvertsen, E.E.. (2009) Ice algae.
Academic chapter
Sakshaug, Egil; Johnsen, Geir; Kristiansen, Svein; von Quillfeldt, Cecilie; Rey, Francisco; Slagstad, Dag; Thingstad, Frede. (2009) Phytoplankton and primary production.
Academic chapter
Johnsen, Geir; Volent, Zsolt; Sakshaug, Egil; Sigernes, Fred; Pettersson, Lasse H.. (2009) Remote sensing in the Barents Sea.
Academic chapter
Elde, Anette Cecilie; Johnsen, Geir. (2009) Pigmentation in deep-water corals from the Trondheimsfjord, Norway. NTNU, Institutt for biologi
Master thesis
Thoen, Hanne Halkinrud; Johnsen, Geir. (2009) Pigmentation in the Arctic deep-sea amphipods Eurythenes gryllus and Anonyx sp. Norges teknisk-naturvitenskapelige universitet
Master thesis
Volent, Z; Johnsen, Geir; Sigernes, Fred. (2009) Microscopic hyperspectral imaging used as a bio-optical taxonomic tool for micro- and macroalgae. Applied Optics
Academic article
Sakshaug, Egil; Johnsen, Geir; Volent, Z.. (2009) Light.
Academic chapter
von Quillfeldt, Cecilie; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik E.. (2009) Ice algae.
Academic chapter
Øye, Ane-Marte; Johnsen, Geir. (2009) Photobioreactor time-series of a simulated bloom of Emiliania huxleyi. Norges teknisk-naturvitenskapelige universitet
Master thesis

2008

Hancke, Torunn Beate; Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2008) Rate of O2 production derived from pulse-amplitude-modulated fluorescence: Testing three biooptical approaches against measured O2-production rate. Journal of Phycology
Academic article
Båtnes, Anna Solvang; Johnsen, Geir. (2008) Trophic interaction between little auks and their zooplankton prey in a high Arctic fjord based on lipid analyses. NTNU, Institutt for biologi
Master thesis
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combined use of AUV and hyperspectral imaging to mapping sea-surface and macroalgae. Ocean Optics
Conference abstract
Bredholt, Harald; Fjærvik, Espen; Johnsen, Geir; Zotchev, Sergey. (2008) Actinomycetes from sediments in the Trondheim Fjord, Norway: Diversity and biological activity. Marine Drugs
Academic article
Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir; Glud, RN. (2008) Temperature effects on microalgal photosynthesis-light responses measured by O2 production, pulse-amplitude-modulated fluorescence, and C-14 assimilation. Journal of Phycology
Academic article
Bakken, Torkild; Evertsen, Jussi; Johnsen, Geir. (2008) Vitenskapelig dykking - behov for endringer i forskriften. Dykkenytt : informasjonsorgan for dykkeindustrien
Professional article

2007

Cibic, Tamara; Blasutto, Oriana; Hancke, Kasper; Johnsen, Geir. (2007) Microphytobenthic species composition, pigment concentration, and primary production in sublittoral sediments of the Trondheimsfjord (Norway). Journal of Phycology
Academic article
Elvestrand, Jostein; Johnsen, Geir; Sneli, Jon-Arne. (2007) Morphometry and patterns of growth in Acesta excavata (Bivalvia: Limidae) from the Trondheimsfjord, Norway. NTNU, Institutt for biologi
Master thesis
Hovland, Erlend Kjeldsberg; Sakshaug, Egil; Johnsen, Geir. (2007) Tracing Coccolithophorid Blooms in the Barents Sea Using MODIS Level-3 Imagery. NTNU, Institutt for biologi
Master thesis
Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir; Naustvoll, L; Throndsen, J. (2007) Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology
Academic article
Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2007) Bio-optical properties and spectral attenuation of photosynthetically available radiation: relation to primary productivity and phytoplankton composition. In Proceedings from Arctic Frontiers: balancing human use and ecosystem protection. UiT Norges arktiske universitet
Research report
Johnsen, Geir; Volent, Zsolt; Sigernes, F.; Berge, Jørgen; Hovland, Erlend Kjeldsberg; Sakshaug, Egil. (2007) Local hyperspectral imaging of ocean colour from tethered balloons in the Arctic. In Proceedings from Arctic Frontiers: Balancing human use and ecosystem protection. UiT Norges arktiske universitet
Research report
Berge, Jørgen; Schander, C; Pampanin, D.M.; Johnsen, Geir. (2007) The past, present and future of the Mytilus edulis population on Svalbard. In Proceedings from Arctic Frontiers: Balancing human use and ecosystem protection. UiT Norges arktiske universitet
Research report
Johnsen, Geir; Volent, Zsolt; Sigernes, F.. (2007) Fine scale studies using hyper-spectral remote sensing. ESSAS Meeting in Marine Arctic Climate
Research report
Johnsen, Geir; Sakshaug, Egil. (2007) Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse-amplitude-modulated and fast-repetition-rate fluorometry. Journal of Phycology
Academic article
Kleiven, Mona; Johnsen, Geir. (2007) Pigmentation in Halocynthia pyriformis from Isfjorden, Spitsbergen. NTNU, Institutt for biologi
Master thesis
Pettersen, Ragnhild; Johnsen, Geir. (2007) Phytoplankton systematics and pigmentation in the Arctic. NTNU, Institutt for biologi
Master thesis
Stübner, Eike; Johnsen, Geir. (2007) Biogeographical distribution of temperate vs. Arctic benthic species around Svalbard. NTNU, Institutt for biologi
Master thesis
Hancke, Kasper; Johnsen, Geir. (2007) Photosynthetic responses as a function of light and temperature: Field and laboratory studies on marine microalgae. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Johnsen, Geir. (2007) Arctic Life: Bridging ecosystem function using remote sensing technologies. Svalbard Science Forum
Popular science article
Carlsen, BP; Johnsen, Geir; Berge, Jørgen; Kuklinski, P. (2007) Biodiversity patterns of macro-epifauna on different lamina parts of Laminaria digitata and Saccharina latissima collected during spring and summer 2004 in Kongsfjorden, Svalbard. Polar Biology
Academic article
Volent, Z; Johnsen, Geir; Sigernes, Fred. (2007) Kelp forest mapping by use of airborne hyperspectral imager. Journal of Applied Remote Sensing
Academic article
Evertsen, Jussi; Burghardt, Ingo; Johnsen, Geir; Wägele, Heike. (2007) Retention of functional chloroplasts in some sacoglossans from the Indo-Pacific and Mediterranean. Marine Biology
Academic article
Ludvigsen, Martin; Sortland, Bjørn; Johnsen, Geir; Singh, Hanumant. (2007) Applications of Geo-Referenced Underwater Photo Mosaics in Marine Biology and Archaeology. Oceanography
Academic article

2006

Olsen, Lasse Mork; Öztürk, M.; Sakshaug, Egil; Johnsen, Geir. (2006) Photosynthesis-induced phosphate precipitation in seawater: ecological implications for phytoplankton. Marine Ecology Progress Series
Academic article
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag; Pampanin, Daniella. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Academic article
Rodriguez, F; Chauton, Matilde Skogen; Johnsen, Geir; Andresen, Kjersti; Olsen, Lasse Mork; Zapata, M.. (2006) Photoacclimation in phytoplankton: implications for biomass estimates, pigment functionality and chemotaxonomy. Marine Biology
Academic article
Sylling, Guro; Thingstad, Per Gustav; Johnsen, Geir. (2006) Marin bunndyrfauna (Gastropoda, Bivalvia) - Konsekvenser av åpning av veifylling over Ramsarområdet Tautrasvaet. NTNU, Institutt for biologi
Master thesis
Carlsen, Beth Paludan; Johnsen, Geir. (2006) Makroepifauna associeret med Laminaria digitata og L. saccharina, Svalbard. NTNU, Institutt for biologi
Master thesis
Johnsen, Geir. (2006) Warming Arctic sees return of blue mussels after 1000 years. National Geographic
Popular science article
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag; Pampanin, Daniela M.. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Editorial
Onstad, L; Evertsen, Jussi; Johnsen, Geir. (2006) Snegle på solceller. Gemini
Popular science article
Roy, Suzanne; Egeland, Einar Skarstad; Johnsen, Geir; Llewellyn, Carole; Wright, Simon. (2006) Report of a Workshop on a Follow-Up Volume of the Book "Phytoplankton Pigments in Oceanography". Scientific Committee on Oceanic Research
Research report

2005

Burghardt, Ingo; Evertsen, Jussi; Johnsen, Geir; Wägele, Heike. (2005) Solar powered seaslugs - Mutualistic symbiosis of aeolid nudibranchia (Mollusca, Gastropoda, Opisthobranchia) with Symbiodinium. Symbiosis
Academic article
Fossmark, Reidar; Johnsen, Geir; Waldum, Helge; Johannesen, Eli Marie. (2005) Rebound acid hypersecretion after long-term inhibition of gastric acid secretion. Alimentary Pharmacology and Therapeutics
Academic article
Olsen, Lasse Mork; Johnsen, Geir. (2005) Interactions between marine osmo- and phagotrophs in different physicochemical environments. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Sakshaug, Egil; Johnsen, Geir. (2005) Algal cultures, Analogues of Blooms and Applications. Multi-Science Publishing
Anthology
Berge, J; Johnsen, Geir; Nilsen, F; Gulliksen, B; Slagstad, D. (2005) Ocean temperature oscillations causes the reappearance of blue mussels in Svalbard after 1000 years of absence. Marine Ecology Progress Series
Academic article
Sakshaug, Egil; Johnsen, Geir. (2005) Absorption, fluorescence excitation and photoacclimation in phytoplankton.
Academic chapter
Chauton, Matilde Skogen; Johnsen, Geir; Sakshaug, Egil. (2005) Nuclear Magnetic Resonance spectroscopy of marine microalgae: Metabolic profiling and species discrimination from High-resolution Magic Angle Spinning NMR analysis of whole-cell samples. NTNU, Institutt for biologi
Doctoral thesis
Bordvik, Hans Otto; Johnsen, Geir. (2005) “En glupsk nellik”. NEWTON websider (NRK)
Popular science article
Indergaard, M; Nordtvedt, M; Johnsen, Geir. (2005) Satellittmålinger for miljøet (SISCAL project, NTNU, IBI). Gemini
Popular science article
Bordvik, Hans Otto; Johnsen, Geir. (2005) “Forskning og foto under vann”. NEWTON websider (NRK)
Popular science article
Valle, Kristin Collier; Johnsen, Geir. (2005) Detection of monthly variation in marine red, brown and green macroalgae by means of in situ video, epifluorescence microscopy and numerical digital image analysis. NTNU, Institutt for biologi
Master thesis
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2005) Ocean temperature oscillations enable reappearance of blue mussels Mytilus edulis in Svalbard after 1000 year absence. Marine Ecology Progress Series
Academic article
Hilstad, Kari; Johnsen, Geir. (2005) In situ tidsseriemålinger av lyshøstingsegenskaper og cellekjemi hos marine makroalger i Trondheimsfjorden. NTNU, Institutt for biologi
Master thesis

2004

Chauton, Matilde Skogen; Tilstone, Gavin; Legrand, Catherine; Johnsen, Geir. (2004) Changes in pigmentation, bio-optical characteristics and photophysiology, during phytoflagellate succession in mesocosms. Journal of Plankton Research
Academic article
Hancke, Torunn Beate; Johnsen, Geir. (2004) SISCAL processor evaluation document. www.siscal.net
Research report

2003

Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL prototype evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
Academic article
Chauton, Matilde Skogen; Optun, Odd Inge; Bathen, F. T; Volent, Z.; Gribbestad, Ingrid S.; Johnsen, Geir. (2003) HR MAS 1H NMR spectroscopy analysis of whole cells of marine microalgae. Marine Ecology Progress Series
Academic article
Figueroa, F. L.; Escassi, L.; Perez-Rodriguez, E.; Korbee, N.; Johnsen, Geir. (2003) Effects of the irradiance in the short-term on accumulation of mycosporine like amino acids in sun and shade species of the red algal genus Porphyra. Photochemistry and Photobiology
Academic article
Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL End User Requirement evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
Academic article

2002

Johnsen, Geir; Børsheim, Knut Yngve; Johansen, Torunn Beate. (2002) Production and mortality of phytoplankton and sea-ice microalgae in the southern ocean. Rapportserie (Norsk polarinstitutt)
Academic article
Millie, David; Schofield, Oscar; Kirkpatrick, Gary J.; Johnsen, Geir; Evens, Tim J.. (2002) Using absorbance and fluorescence spectra to discriminate microalgae. European journal of phycology
Academic article
Gileptis, Laura; Johnsen, Geir; Moxness, Helge; Norwich, Inger; Vangen, Steffen. (2002) Modul for mønstergjenkjenning/klassifisering i DynamicImager ved bruk av backpropagation-algoritmen. Piksel'n : Organ for NOBIM (Norsk forening for bildebehandling og mønstergjenkjenning)
Academic article
Johansen, Torunn Beate; Johnsen, Geir. (2002) End User requirement evaluation document. [Mangler utgivernavn]
Research report
Johansen, Torunn Beate; Johnsen, Geir. (2002) End User Requirements document. [Mangler utgivernavn]
Research report

1992

Syvertsen, E.; Hegseth, E; Johnsen, Geir; Sakshaug, Egil; Gulliksen, B; Lønne, O. J; Aarseth, A. (1992) Livet i isen (The life in the ice). In Økosystem Barentshavet. [Mangler utgivernavn]
Non-fiction monograph
Sakshaug, Egil; Kristiansen, S; Syvertsen, E; Eilertsen, H. C; Gilstad, M; Hegseth, E. N; Hewes, C; Holm-Hansen, O; Johnsen, Geir; Mitchell, B. G. (1992) Planktonalger (Phytoplankton). In Økosystem Barentshavet. [Mangler utgivernavn]
Non-fiction monograph
Johnsen, Geir; Sakshaug, Egil; Vernet, Maria. (1992) Pigment composition, spectral characteriation and photosynthetic parameters in Chrysochromulina polylepis. Marine Ecology Progress Series
Academic article
Volent, Zsolt; Johnsen, Geir. (1992) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a moored buoy. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
Academic article
Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1992) Bio-optical characteristicts of phytoplankton in relation to remote sensing. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
Academic article

1991

Sakshaug, Egil; Johnsen, Geir; Andresen, Kjersti; Vernet, Maria. (1991) Modeling of light-dependent algal photosynthesis and growth: Experiments with the Barents Sea diatoms Thalassiosira nordensskioeldii and Chaetocero furcellatus. Deep-Sea Research Part II: Topical Studies in Oceanography
Academic article
Johnsen, Geir; Hegseth, Else Nøst. (1991) Photoadaptation of sea-ice microalgae in the Barents Sea. Polar Biology
Academic article
Johnsen, Geir. (1991) Identification of Chrysochromulina leadbeateri by means of remote sensing. Fisken og Havet
Academic article
Sakshaug, Egil; Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1991) Identification of phytoplankton blooms by means of remote sensing. Environment Northern Seas
Academic article
Johnsen, Geir. (1991) Proceedings from a scientific working meeting. Fisken og Havet
Academic article

Journal publications

Summers, Natalie Maria; Bremnes, Jens Einar; Liu, Hongbo; Løvås, Håvard Snefjellå; Moreira Fragoso, Glaucia; Johnsen, Geir. (2026) Assessing Arctic under sea-ice light regimes and ice algal bio-optical properties using ROV-based hyperspectral imaging. Polar Biology
Academic article
Moreira Fragoso, Glaucia; Hama, Nalia; Snijder, Elisabeth; Aldridge, David; Borrero Santiago, Ana Rocio; Broch, Ole Jacob; Johnsen, Geir; Olsen, Yngvar; Hatlebakk, Maja Karoline Viddal. (2026) The influence of environmental factors and phytoplankton blooms on cyphonautes larvae abundance and bryozoan colony development at a kelp farm in central Norway. Marine Environmental Research
Academic article
Paiba Garcia, Laura Catherine; Johnsen, Geir; Perrin, Sam Wenaas; Bakken, Torkild. (2025) Open‐Source Marine Biodiversity Data Quality in the Norwegian Sea Spanning 149 Years: Knowledge Gaps in the Deep‐Sea Mining Opening Area. Ecology and Evolution
Academic article
Johnsen, Geir; Børsheim, Knut Yngve; Johansen, Torunn Beate. (2002) Production and mortality of phytoplankton and sea-ice microalgae in the southern ocean. Rapportserie (Norsk polarinstitutt)
Academic article
Kauko, Hanna Maria; Pavlov, Alexey; Johnsen, Geir; Granskog, Mats; Peeken, Ilka; Assmy, Philipp. (2019) Photoacclimation state of an Arctic underice phytoplankton bloom. Journal of Geophysical Research (JGR): Oceans
Academic article
Kauko, Hanna Maria; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C.J.; Duarte, Pedro; Fernández-Méndez, Mar; Olsen, Lasse Mork; Hudson, Stephen R.; Johnsen, Geir. (2017) Windows in Arctic sea ice: light transmission and ice algae in a refrozen lead. Journal of Geophysical Research (JGR): Biogeosciences
Academic article
Schartmüller, Bernhard; Mckee, David; Berge, Jørgen; Johnsen, Geir. (2024) Calibration verification of an underwater hyperspectral imaging push broom instrument to measure light in absolute units and field demonstration. Applied Optics
Academic article
Ringvold, Halldis; Taite, Morag; Allcock, A. Louise; Vecchione, Michael; Péan, Michel; Sandulli, Roberto; Johnsen, Geir; Fjellheim, Arne; Bakke, Snorre; Sannæs, Hanne. (2021) In situ recordings of large gelatinous spheres from NE Atlantic, and the first genetic confirmation of egg mass of Illex coindetii (Vérany, 1839) (Cephalopoda, Mollusca). Scientific Reports
Academic article
Hancke, Torunn Beate; Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2008) Rate of O2 production derived from pulse-amplitude-modulated fluorescence: Testing three biooptical approaches against measured O2-production rate. Journal of Phycology
Academic article
Cibic, Tamara; Blasutto, Oriana; Hancke, Kasper; Johnsen, Geir. (2007) Microphytobenthic species composition, pigment concentration, and primary production in sublittoral sediments of the Trondheimsfjord (Norway). Journal of Phycology
Academic article
Olsen, Lasse Mork; Öztürk, M.; Sakshaug, Egil; Johnsen, Geir. (2006) Photosynthesis-induced phosphate precipitation in seawater: ecological implications for phytoplankton. Marine Ecology Progress Series
Academic article
Bazilchuk, Nancy Reney; Fossum, Trygve Olav; Moreira Fragoso, Glaucia; Ludvigsen, Martin; Johnsen, Geir. (2019) Smart undervannsrobot leter etter plankton. Av N Bazilchuk. Forskning.no. Angående NTNU Entice prosjekt publisert i Science Robotics. Forskning.no
Popular science article
Burghardt, Ingo; Evertsen, Jussi; Johnsen, Geir; Wägele, Heike. (2005) Solar powered seaslugs - Mutualistic symbiosis of aeolid nudibranchia (Mollusca, Gastropoda, Opisthobranchia) with Symbiodinium. Symbiosis
Academic article
Bazilchuk, Nancy Reney; Berge, Jørgen; Johnsen, Geir. (2021) Lysforurensning I Arktis kan ha ødelagt forskningsresultater. Gemini.no
Popular science article
Cardwell, CR; Berge, Jørgen; Johnsen, Geir. (2021) Arctic voyage shines light on some cold, hard truths. The Herald, UK
Popular science article
Bazilchuk, Nancy Reney; Stahl, Annette; Johnsen, Geir; Saad, Aya; Thu, Maren; Nøland, Annecken; Aberle-Malzahn, Nicole. (2021) Sporhunden som lukter mikroalger. Gemini.no
Popular science article
Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL prototype evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
Academic article
Hovland, Erlend Kjeldsberg; Dierssen, Heidi; Ferreira, Ana Sofia; Johnsen, Geir. (2013) Dynamics regulating major trends in Barents Sea temperatures and subsequent effect on remotely sensed particulate inorganic carbon. Marine Ecology Progress Series
Academic article
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag; Pampanin, Daniella. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Academic article
Evertsen, Jussi; Johnsen, Geir. (2009) In vivo and in vitro differences in chloroplast functionality in the two north Atlantic sacoglossans (Gastropoda, Opisthobranchia) Placida dendritica and Elysia viridis. Marine Biology
Academic article
Volent, Zsolt; Johnsen, Geir; Hovland, Erlend Kjeldsberg; Folkestad, Are; Olsen, Lasse Mork; Tangen, Karl; Sørensen, Kai. (2011) Improved monitoring of phytoplankton bloom dynamics in a Norwegian fjord by integrating satellite data, pigment analysis, and Ferrybox data with a coastal observation network. Journal of Applied Remote Sensing
Academic article
Donahue, Michelle; Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) The age of humans - living in the anthropocene - "Termites of the sea" found munching wood near Arctic shipwrecks. Smithsonian
Popular science article
Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Moreira Fragoso, Glaucia; Berge, Jørgen. (2022) Underwater Hyperspectral Imaging of Arctic Macroalgal Habitats during the Polar Night Using a Novel Mini-ROV-UHI Portable System. Remote Sensing
Academic article
Førde, Henny; Forbord, Silje; Handå, Aleksander; Fossberg, Julia; Arff, Johanne; Johnsen, Geir; Reitan, Kjell Inge. (2016) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. Journal of Applied Phycology
Academic article
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combined use of AUV and hyperspectral imaging to mapping sea-surface and macroalgae. Ocean Optics
Conference abstract
Ramirez-Llodra, Eva; Hilário, Ana; Paulsen, Emil; Costa, Carolina; Bakken, Torkild; Johnsen, Geir; Rapp, Hans Tore. (2020) Benthic Communities on the Mohn’s Treasure Mound: Implications for Management of Seabed Mining in the Arctic Mid-Ocean Ridge. Frontiers in Marine Science
Academic article
Ødegård, Øyvind; Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging: a new tool for marine archaeology. Applied Optics
Academic article
Rodriguez, F; Chauton, Matilde Skogen; Johnsen, Geir; Andresen, Kjersti; Olsen, Lasse Mork; Zapata, M.. (2006) Photoacclimation in phytoplankton: implications for biomass estimates, pigment functionality and chemotaxonomy. Marine Biology
Academic article
Pettersen, Ragnhild; Johnsen, Geir; Bruheim, Per; Andreassen, Trygve. (2013) Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms. Organisms Diversity & Evolution
Academic article
Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir; Naustvoll, L; Throndsen, J. (2007) Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology
Academic article
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig; Renaud, Paul; Leu, Eva; Grenvald, Julie Cornelius; Cottier, Finlo. (2015) Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?. PLOS ONE
Academic article
Fossmark, Reidar; Johnsen, Geir; Waldum, Helge; Johannesen, Eli Marie. (2005) Rebound acid hypersecretion after long-term inhibition of gastric acid secretion. Alimentary Pharmacology and Therapeutics
Academic article
Moreira Fragoso, Glaucia; Davies, Emlyn John; Ellingsen, Ingrid H.; Chauton, Matilde Skogen; Fossum, Trygve Olav; Ludvigsen, Martin; Steinhovden, Kristine; Rajan, Kanna; Johnsen, Geir. (2019) Physical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspot. Progress in Oceanography
Academic article
Dumke, Ines; Purser, Autun; Marcon, Yann; Nornes, Stein Melvær; Johnsen, Geir; Ludvigsen, Martin; Søreide, Fredrik. (2018) Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports
Academic article
Schartmuller, Bernhard; Anderson, Philip; Mckee, David; Connan-McGinty, Stacey; Kopec, Tomasz Piotr; Daase, Malin Hildegard Elisabeth; Johnsen, Geir; Berge, Jørgen. (2023) Development and calibration of a high dynamic range and autonomous ocean-light instrument to measure sub-surface profiles in ice-covered waters. Applied Optics
Academic article
Moreira Fragoso, Glaucia; Johnsen, Geir; Chauton, Matilde Skogen; Cottier, Finlo Robert; Ellingsen, Ingrid H.. (2020) Phytoplankton community succession and dynamics using optical approaches. Continental Shelf Research
Academic article
Williamson, David Roddan; Moreira Fragoso, Glaucia; Majaneva, Sanna Kristiina; Dallolio, Alberto; Halvorsen, Daniel Ørnes; Hasler, Oliver Kevin; Oudijk, Adriënne Esmeralda; Langer, Dennis David; Johansen, Tor Arne; Johnsen, Geir. (2023) Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography
Academic article
Berge, Jørgen; Lønne, Ole Jørgen; Renaud, Paul; Johnsen, Geir; Gulliksen, Bjørn; Varpe, Øystein; Nygård, Henrik. (2009) Polartorsken - vil den bli utkonkurrert av sørlige fiskearter?. Svalbardposten
Popular science article
Kauko, Hanna Maria; Olsen, Lasse Mork; Duarte, Pedro; Peeken, Ilka; Granskog, Mats A.; Johnsen, Geir; Fernández-Méndez, Mar; Pavlov, Alexey; Mundy, Christopher John; Assmy, Philipp. (2018) Algal colonization of young arctic sea ice in spring. Frontiers in Marine Science
Academic article
Berge, Jørgen; Cottier, Finlo; Last, Kim S.; Varpe, Øystein; Leu, Eva; Søreide, Janne; Eiane, Ketil; Falk-Petersen, S.; Willis, Kate; Nygård, Henrik. (2009) Diel vertical migration of Arctic zooplankton during the polar night. Biology Letters
Academic article
Cohen, Jonathan; Cronin, Heather; Moline, Mark A.; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Are krill eyes useful in the high Arctic polar night?. Ocean Optics
Conference abstract
Johnsen, Geir; Norli, Marit; Moline, Mark A.; Robbins, Ian; von Quillfeldt, Cecilie; Sørensen, Kai; Cottier, Finlo Robert; Berge, Jørgen. (2018) The advective origin of an under-ice spring bloom in the Arctic Ocean using multiple observational platforms. Polar Biology
Academic article
Aamot, Inga; Pokrzywinski, Kaytee; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan. (2014) Light Climate and Status of the Photosynthetic Machinery in Macroalgae in the Polar Night. Ocean Optics
Conference abstract
Hansen, Ingrid; Pettersen, Ragnhild; Beuchel, Frank; Cochrane, Sabine; Frantzen, marianne; Ekehaug, Stefan; Erdal, Ivar; Johnsen, Geir; Camus, Lionel. (2014) Underwater hyperspectral imaging (UHI) for environmental mapping and monitoring of seabed habitats. Ocean Optics
Conference abstract
Berge, J; Johnsen, Geir; Nilsen, F; Gulliksen, B; Slagstad, D. (2005) Ocean temperature oscillations causes the reappearance of blue mussels in Svalbard after 1000 years of absence. Marine Ecology Progress Series
Academic article
Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.; Johnsen, Geir; Mckee, David; Kostakis, Ina; Renaud, Paul Eric. (2020) Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth. Communications Biology
Academic article
Berge, Jørgen; Johnsen, Geir; Falk-Pettersen, Stig. (2013) Mørkets hemmeligheter. Svalbardposten
Popular science article
Nilssen, Ingunn; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen; Nornes, Stein Melvær; Norgren, Petter; Vieweg, Ireen. (2014) Integrated environmental monitoring; a methodological approach to optimise knowledge gathering and sampling strategy. Ocean Optics
Conference abstract
Johnsen, Geir; Ekehaug, Stefan; Hansen, Ingrid; Sørensen, Asgeir Johan. (2014) The use of underwater hyperspectral imaging deployed on remotely operated vehicles to identify, map and monitor bio-geo-chemical objects of interest. Ocean Optics
Conference abstract
Nornes, Stein Melvær; Candeloro, Mauro; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Photomosaic camera as simultaneous data collector and navigation aid on unmanned underwater vehicles. Ocean Optics
Conference abstract
Johnsen, Geir. (2006) Warming Arctic sees return of blue mussels after 1000 years. National Geographic
Popular science article
Summers, Natalie Maria; Moreira Fragoso, Glaucia; Johnsen, Geir. (2023) Photophysiologically active green, red, and brown macroalgae living in the Arctic Polar Night. Scientific Reports
Academic article
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag; Pampanin, Daniela M.. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Editorial
Mogstad, Aksel Alstad; Løvås, Håvard; Sture, Øystein; Johnsen, Geir; Ludvigsen, Martin. (2022) Remote Sensing of the Tautra Ridge: An Overview of the World’s Shallowest Cold-Water Coral Reefs. Frontiers in Marine Science
Academic article
Johnsen, Geir; Sakshaug, Egil. (2007) Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse-amplitude-modulated and fast-repetition-rate fluorometry. Journal of Phycology
Academic article
Oudijk, Esmée; Hasler, Oliver Kevin; Øveraas, Henning; Marty, Sabine; Williamson, David Roddan; Svendsen, Torbjørn Karl; Berg, Simen; Birkeland, Roger; Halvorsen, Daniel Ørnes; Bakken, Sivert. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Academic article
Onstad, L; Evertsen, Jussi; Johnsen, Geir. (2006) Snegle på solceller. Gemini
Popular science article
Dumke, Ines; Nornes, Stein Melvær; Purser, Autun; Marcon, Yann; Ludvigsen, Martin; Ellefmo, Steinar Løve; Johnsen, Geir; Søreide, Fredrik. (2018) First hyperspectral imaging survey of the deep seafloor: High-resolution mapping of manganese nodules. Remote Sensing of Environment
Academic article
Faltynkova, Andrea; Johnsen, Geir; Wagner, Martin. (2021) Hyperspectral imaging as an emerging tool to analyze microplastics: A systematic review and recommendations for future development. Microplastics and Nanoplastics
Academic literature review
Moreira Fragoso, Glaucia; Davies, Emlyn John; Fossum, Trygve Olav; Ullgren, Jenny; Majaneva, Sanna; Aberle-Malzahn, Nicole; Ludvigsen, Martin; Johnsen, Geir. (2022) Contrasting phytoplankton-zooplankton distributions observed through autonomous platforms, in-situ optical sensors and discrete sampling. PLOS ONE
Academic article
Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Lågstad, Petter Arthur; Ødegård, Øyvind. (2014) Scientific Operations Combining ROV and AUV in the Trondheim Fjord. Marine Technology Society journal
Academic article
Chauton, Matilde Skogen; Tilstone, Gavin; Legrand, Catherine; Johnsen, Geir. (2004) Changes in pigmentation, bio-optical characteristics and photophysiology, during phytoflagellate succession in mesocosms. Journal of Plankton Research
Academic article
Moreira Fragoso, Glaucia; Dallolio, Alberto; Grant, Stephen Denis; Garrett, Joseph Landon; Ellingsen, Ingrid Helene; Johnsen, Geir; Johansen, Tor Arne. (2024) The Role of Rapid Changes in Weather on Phytoplankton Spring Bloom Dynamics Captured by an Autonomous Uncrewed Surface Vehicle. Earth and Space Science
Academic article
Mogstad, Aksel Alstad; Johnsen, Geir; Ludvigsen, Martin. (2019) Shallow-Water Habitat Mapping using Underwater Hyperspectral Imaging from an Unmanned Surface Vehicle: A Pilot Study. Remote Sensing
Academic article
Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2019) Sea surface microlayer and elemental composition in phaeo-, chloro-, and rhodophytes in winter and spring. Journal of Phycology
Academic article
Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2020) Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots. Remote Sensing
Academic article
Fossum, Trygve Olav; Eidsvik, Jo; Ellingsen, Ingrid H.; Alver, Morten; Moreira Fragoso, Glaucia; Johnsen, Geir; Mendes, Renato; Ludvigsen, Martin; Rajan, Kanna. (2018) Information-driven robotic sampling in the coastal ocean. Journal of Field Robotics (JFR)
Academic article
Fossum, Trygve Olav; Moreira Fragoso, Glaucia; Davies, Emlyn John; Ullgren, Jenny; Mendes, Renato; Johnsen, Geir; Ellingsen, Ingrid H.; Eidsvik, Jo; Ludvigsen, Martin; Rajan, Kanna. (2019) Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Science robotics
Academic article
Ingulstad, Mats; Bakken, Torkild; Ellefmo, Steinar Løve; Johnsen, Geir; Hagspiel, Verena. (2024) Villedende om hypotetiske havbunnsmineraler?. Dagens næringsliv
Commentary
Horni, K; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin. (2021) Internasjonalt forskningsmiljø dykker i Mjøsa etter at Oppland Arbeiderblad skrev om forurensning. Oppland arbeiderblad
Popular science article
Mo-Bjørkelund, Tore; Majaneva, Sanna Kristiina; Moreira Fragoso, Glaucia; Johnsen, Geir; Ludvigsen, Martin. (2024) Multi-vehicle adaptive 3D mapping for targeted ocean sampling. PLOS ONE
Academic article
Jovine, R. V.; Johnsen, Geir; Prezelin, B. B.. (1995) Isolation of membrane bound chlorophyll a-chlorofhyll c binding light harvesting complexes from the dinoflagellates heterocapsa pygmaea and Prorocentrum minimum. Photosynthesis Research
Academic article
Jovine, R. V.; Schofield, O.; Johnsen, Geir; Prezelin, B. B.. (1994) Photoacclimatory differences in the light-harvesting complex of the bloom forming dinoflagellates Heterocapsa pygmaea and Prorocentrum minimum. Journal of Phycology
Academic article
Vernet, M.; Mitchell, B. G.; Sakshaug, Egil; Johnsen, Geir; Iturriaga, R.; Wassmann, P.. (1996) Evidence for a novel pigment with in vivo absorption maximum at 708 nm associated with Phaeocystis sp. blooms. Marine Ecology Progress Series
Academic article
Johnsen, Geir; Prezelin, B. B.; Jovine, R. V. M.. (1997) Fluorescence excitation spectra and light utiliation in two red tide dinoflagellates. Limnology and Oceanography
Academic article
Sakshaug, Egil; Johnsen, Geir; Andresen, Kjersti; Vernet, Maria. (1991) Modeling of light-dependent algal photosynthesis and growth: Experiments with the Barents Sea diatoms Thalassiosira nordensskioeldii and Chaetocero furcellatus. Deep-Sea Research Part II: Topical Studies in Oceanography
Academic article
Løvås, Håvard; Mogstad, Aksel Alstad; Sørensen, Asgeir Johan; Johnsen, Geir. (2021) A Methodology for Consistent Georegistration in Underwater Hyperspectral Imaging. IEEE Journal of Oceanic Engineering
Academic article
Faltynkova, Andrea; Deschenes, Catherine; Zolich, Artur; Wagner, Martin; Johansen, Tor Arne; Johnsen, Geir. (2024) Use of an uncrewed surface vehicle and near infrared hyperspectral imaging for sampling and analysis of aquatic microplastics. Marine Pollution Bulletin
Academic article
Johnsen, Geir; Sakshaug, Egil; Vernet, Maria. (1992) Pigment composition, spectral characteriation and photosynthetic parameters in Chrysochromulina polylepis. Marine Ecology Progress Series
Academic article
Johnsen, Geir; Hegseth, Else Nøst. (1991) Photoadaptation of sea-ice microalgae in the Barents Sea. Polar Biology
Academic article
Egeland, E.; Johnsen, Geir; Eikrem, W.; Jensen, S. Liaaen-; Throndsen, J.. (1995) The pigments of Bathycoccus prasinos. Journal of Phycology
Academic article
Schofield, O.; Prezelin, B. B.; Johnsen, Geir. (1996) Wavelength-dependency of maximum quantum yield of carbon fixation for two red tide dinoflagellates, Heterocapsa pygmaea and prorocentrum minimum. Journal of Phycology
Academic article
Johnsen, Geir; Sakshaug, Egil. (1996) Light harvesting in bloom-forming marine phytoplankton: Species-specifity and photoacclimation,. Scientia Marina
Academic article
Berge, Jørgen; Renaud, Paul E.; Johnsen, Geir; Darnis, Gerald; Geoffroy, Maxime; Daase, Malin; Kwasniewski, S; Draganska, K; Cottier, Finlo Robert; Falk-Petersen, Stig. (2016) I grenselandet (mellom Tull og Thule). Svalbardposten
Popular science article
Gilstad, Mona; Johnsen, Geir; Sakshaug, Egil. (1993) Photosynthetic parameters, pigment composition and respiration rates of the marine diatom Skeletonema costatum grown in continuous light and a 12:1 light-dark cycle. Journal of Plankton Research
Academic article
Johnsen, Geir; Samset, O.; Granskog, L.; Sakshaug, Egil. (1994) In vivo absorption characteristics in 10 classes of phytoplankton: Taxonomic characteristics and responses to photoadaption by means of discriminant and HPLC analysis. Marine Ecology Progress Series
Academic article
Johnsen, Geir; Sakshaug, Egil. (1993) Bio-optical characteristics and photoadaptive responses in the toxic and bloomforming dinoflagellates Gyrodinium aureolum, Gymnodinium galatheanum two strains of Prorocentrum minium. Journal of Phycology
Academic article
Johnsen, Geir; Nelson, N. B.; Jovine, R. V. M.; Prezelin, B. B.. (1994) Chromoprotein- and pigment-dependent modeling of spectral light absorption in two dinoflagellates, Prorocentrum minimum and Heterocapsa pygmaea. Marine Ecology Progress Series
Academic article
Haugstad, Tor; Erdal, Ivar; Johnsen, Geir; Sørensen, Asgeir Johan; Fjærvik, Nils. (2016) Gründerne mener dette kameraet kan bli det nye ekkoloddet – Ecotone er kandidat til TU Tech Award. Teknisk Ukeblad
Popular science article
Aarskog, Karine Nigar; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2016) Et stort løft for arktisk forskning (NTNU & UiT). Universitetet i Tromsø
Professional article
Haudemann-Andersen, Jørn; Lystad, M S; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2016) Blå lys i det kalde dyp. NRK Trøndelag, Nyheter
Popular science article
Bazilchuk, Nancy Reney; Leite, Stein Roar; Johnsen, Geir; Kjeken, John; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2016) Bomber og buss på havbunnen. Gemini
Popular science article
Mogstad, Aksel Alstad; Johnsen, Geir. (2017) Spectral characteristics of coralline algae: a multi-instrumental approach, with emphasis on underwater hyperspectral imaging. Applied Optics
Academic article
Berge, Jørgen; Bakken, Torkild; Heggland, Kristin; Sneli, Jon-Arne; Ødegård, Øyvind; Ingulstad, Mats; Thun, Terje; Johnsen, Geir. (2025) Exploring Climate Change, Geopolitics, Marine Archeology, and Ecology in the Arctic Ocean Through Wood-Boring Bivalves. Oceanography
Academic article
Deschenes, C; Zolich, Artur; Wagner, Martin; Johnsen, Geir; Johansen, Tor Arne; Faltynkova, Andrea. (2023) Unmanned vehicle and hyperspectral imager for a more rapid microplastics sampling and analysis. OCEANS
Academic article
oudijk, AE; Johansen, Tor Arne; Johnsen, Geir; Alver, Morten Omholt. (2023) Simulating Hyperspectral Datacubes for Ocean Color: A Foundation for Phytoplankton Recognition in Spectral Signatures. OCEANS
Academic article
Johnsen, Geir. (2016) Yrende liv i Isfjorden. Svalbardposten
Popular science article
Gabrielsen, Tove M; von Quillfeldt, Cecilie; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden. Svalbardposten
Commentary
Berge, Jørgen; Cottier, Finlo; Varpe, Øystein; Renaud, Paul; Falk-Petersen, Stig; Kwasniewski, Sawomir; Griffiths, Colin; Søreide, Janne; Johnsen, Geir; Aubert, Anais. (2014) Arctic complexity: A case study on diel vertical migration of zooplankton. Journal of Plankton Research
Academic article
Krüger, Frida Jørstad; Johnsen, Geir; Kjeken, John; Ludvigsen, Martin. (2016) Gammel buss ble korallrev. NRK Viten
Popular science article
Lervik, Frank; Johnsen, Geir; Ludvigsen, Martin; Kjeken, John. (2016) Det ligger flere busser der. Adresseavisen
Popular science article
Bjørgan, Espen Halvorsen; Johnsen, Geir; Kjeken, Jon; Ludvigsen, Martin. (2016) Fant buss på 600 m dybde. Adresseavisen
Popular science article
Berge, Jørgen; Falk-Petersen, Stig; Renaud, Paul E.; Daase, Malin; Geoffroy, Maxime; Johnsen, Geir. (2016) En reise mot Ultima Thule. Svalbardposten
Popular science article
Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura; Johnsen, Geir; Berge, Jørgen. (2021) Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biology
Academic article
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Ludvigsen, Martin; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Mørkets fyrster, varulver og Indiana Jones. Gemini
Popular science article
Neves, Luiza S.; Smeby, Kristin; Broch, Ole Jacob; Johnsen, Geir; Ardelan, Murat van; Skjermo, Jorunn. (2025) Particulate and dissolved organic carbon losses in high latitude seaweed farms. Science of the Total Environment
Academic article
Kokkegård, Hanne; Johnsen, Geir; Ludvigsen, Martin; Torre, Pedro De La. (2016) Vitenskab - Bomber fra 2 verdenskrig danner koralrev på 600 m dybde. Danmarks radio
Popular science article
Moreira Fragoso, Glaucia; Dallolio, Alberto; Grant, Stephen Denis; Garrett, Joseph Landon; Ellingsen, Ingrid Helene; Johnsen, Geir; Johansen, Tor Arne. (2024) The Role of Rapid Changes in Weather on Phytoplankton Spring Bloom Dynamics From Mid-Norway Using Multiple Observational Platforms. Journal of Geophysical Research (JGR): Oceans
Academic article
Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert; Mogstad, Aksel Alstad; Zolich, Artur Piotr; Last, Kim. (2018) Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic. Polar Biology
Academic article
Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan H.; Mckee, David; Kopec, Tomasz Piotr; Vogedes, Daniel Ludwig; Berge, Jorgen. (2021) All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic. Applied Optics
Academic article
Elde, Anette; Pettersen, Ragnhild; Bruheim, Per; Järnegren, Johanna; Johnsen, Geir. (2012) Pigmentation and Spectral Absorbance Signatures in Deep-Water Corals from the Trondheimsfjord, Norway. Marine Drugs
Academic article
Legrand, Catherine; Johnsen, Geir; Graneli, Edna; Sakshaug, Egil. (2001) (Proceedings of the 9th International conference on Harmful Algal Blooms. Hobart, Tasmania, 7-11 February 2000.) Effect of polyamines on growth and toxicity of Chrysochromulina leadbeateri, Haptophytae. Phycologia
Academic article
Legrand, Catherine; Johansson, Niclas; Johnsen, Geir; Børsheim, Knut Yngve; Graneli, Edna. (2001) Phagotrophy and toxicity in the photosynthetic Prymnesium patelliferum (Haptophyte). Limnology and Oceanography
Academic article
Wägele, Heike; Johnsen, Geir. (2001) New results on histology and photosynthetic performance of solar-powered� opisthobranchs (Mollusca, Gastropoda, Opisthobranchia) containing symbiotic chloroplasts or zooxanthellae. Organisms Diversity & Evolution
Academic article
Nilssen, Ingunn; Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Moline, Mark A.; Berge, Jørgen. (2015) Integrated environmental mapping and monitoring, a methodological approach to optimise knowledge gathering and sampling strategy. Marine Pollution Bulletin
Academic article
Graneli, Edna; Legrand, Catherine; Carlsson, Per; Johnsen, Geir; Maestrini, Serge Y.; Reichelt, Michael; Hummert, Christian; Luckas, Bernt; Pallon, Jan; Sakshaug, Egil. (2001) (Proceedings of the 9th International conference on Harmful Algal Blooms. Hobart, Tasmania, 7-11 February 20). Structuration of marine phytoplankton communities subjected to different levels of N, P and Si limitation in a mesocosm experiment (summary paper). Phycologia
Academic article
Gabrielsen, Tove M.; Johnsen, Geir. (2018) Skogen på Svalbard. Svalbardposten
Popular science article
Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2011) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
Academic article
Bakken, Sivert; Johnsen, Geir; Johansen, Tor Arne. (2021) Analysis and Model Development of Direct Hyperspectral Chlorophyll-A Estimation for Remote Sensing Satellites. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Academic article
Berge, Jørgen; Johnsen, Geir. (2016) Mørkets fyrster med påskrudd lys. Svalbardposten
Popular science article
Johnsen, Geir. (2007) Arctic Life: Bridging ecosystem function using remote sensing technologies. Svalbard Science Forum
Popular science article
Volent, Zsolt; Johnsen, Geir. (1992) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a moored buoy. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
Academic article
Volent, Zsolt; Johnsen, Geir. (1993) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a buoy. Underwater light measurements. Proceedings from International Symposium on high latitude optics.
Academic article
Seppala, J; Johnsen, Geir; Babichenko, S; Leeben, A; Poryvkina, L; Shalapyonok, [Mangler fornavn]. (1998) In vivo light absorption by photosynthetic and photoprotective algal pigments: Methodology and the effects of light acclimation and nutrient limitation. Report Series in Geophysics
Academic article
Johnsen, Geir; Dalløkken, Runar; Aure, J; Skjoldal, H. R. (1998) Photophysiology and environmental conditions during a toxic bloom of Chrysochromulina leadbeateri (Prymnesiophyceae). International symposium on Harmful Algal Blooms
Academic article
Johnsen, Geir. (1991) Identification of Chrysochromulina leadbeateri by means of remote sensing. Fisken og Havet
Academic article
Bordvik, Hans Otto; Johnsen, Geir. (2005) “En glupsk nellik”. NEWTON websider (NRK)
Popular science article
Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.; Johnsen, Geir; Seuthe, Lena; Weslawski, Jan Marcin; Leu, Eva. (2015) In the dark: a review of ecosystem processes during the Arctic polar night. Progress in Oceanography
Academic article
Berge, Jørgen; Daase, Malin; Renaud, Paul; Ambrose, William G. Jr.; Darnis, Gérald; Last, Kim S; Leu, Eva; Cohen, Jonathan H.; Johnsen, Geir; Moline, Mark A.. (2015) Unexpected levels of biological activity during the polar night offer new perspectives on a warming Arctic. Current Biology
Academic article
Båtnes, Anna Solvang; Miljeteig, Cecilie; Berge, Jørgen; Greenacre, Michael; Johnsen, Geir. (2013) Quantifying the light sensitivity of Calanus spp. during the polar night: potential for orchestrated migrations conducted by ambient light from the sun, moon, or aurora borealis. Polar Biology
Academic article
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Mark spiser opp vrak på havbunnen. Fiskaren
Popular science article
Bondø, Tor-Hartvig; Johnsen, Geir; Berge, Jørgen. (2016) Fant yrende liv i polarnatta. VG : Verdens gang
Popular science article
Johnsen, Geir; Ludvigsen, Martin; Sørensen, Asgeir Johan; Aas, Lars Martin Sandvik. (2016) The use of underwater hyperspectral imaging deployed on remotely operated vehicle – methods and applications. IFAC-PapersOnLine
Academic article
Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Winge, Per; Hancke, Kasper; Andresen, Kjersti; Johnsen, Geir; Bones, Atle M.. (2009) An integrated analysis of molecular acclimation to high light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Academic article
Bredholt, Harald; Fjærvik, Espen; Johnsen, Geir; Zotchev, Sergey. (2008) Actinomycetes from sediments in the Trondheim Fjord, Norway: Diversity and biological activity. Marine Drugs
Academic article
Aamot, Inga; Berge, Jørgen; Hancke, Kasper; Johnsen, Geir; Moline, Mark; Schofield, Oscar. (2010) NORUS - Technology Development for Marine Monitoring and Ocean Observation:An North America-Norway educational program. http://ipy-osc.no/abstract/
Conference abstract
Johnsen, Geir; Volent, Z; Tangen, K; Sakshaug, Egil. (1996) Time-series of potential toxic phytoplankton blooms in North European waters in 1993 using the SEAWATCH-Europe buoy system. EOS
Academic article
Jovine, R. V; Johnsen, Geir; Prezelin, B. B. (1994) Photoadaptation of Prorocentrum minimum and Heterocapsa pygmaea (Dinoflagellates): Chromoprotein changes and the consequenses for spectral absorption. EOS
Academic article
Sakshaug, Egil; Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1991) Identification of phytoplankton blooms by means of remote sensing. Environment Northern Seas
Academic article
Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1992) Bio-optical characteristicts of phytoplankton in relation to remote sensing. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
Academic article
Pettersen, Ragnhild; Johnsen, Geir; Berge, Jørgen; Hovland, Erlend Kjeldsberg. (2011) Phytoplankton chemotaxonomy in waters around the Svalbard archipelago reveals high amounts of Chl b and presence of gyroxanthin-diester. Polar Biology
Academic article
Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2010) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
Academic article
Millie, D; Shofield, O. M; Kirkpatrick, G. J; Tester, P. A; Johnsen, Geir. (1996) Using bio-optical characterisics as bio-markers for harmful algal blooms: A case study of the Florida red-tide dinoflagellate,. EOS
Academic article
Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Glowing in the dark: Discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
Academic article
Indergaard, M; Nordtvedt, M; Johnsen, Geir. (2005) Satellittmålinger for miljøet (SISCAL project, NTNU, IBI). Gemini
Popular science article
Bordvik, Hans Otto; Johnsen, Geir. (2005) “Forskning og foto under vann”. NEWTON websider (NRK)
Popular science article
Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir; Glud, RN. (2008) Temperature effects on microalgal photosynthesis-light responses measured by O2 production, pulse-amplitude-modulated fluorescence, and C-14 assimilation. Journal of Phycology
Academic article
Grant, Stephen Denis; Johnsen, Geir; Mckee, David; Zolich, Artur Piotr; Cohen, Jonathan H.. (2023) Spectral and RGB analysis of the light climate and its ecological impacts using an all-sky camera system in the Arctic. Applied Optics
Academic article
Liu, Hongbo; Summers, Natalie Maria; Chen, Yi-Chun; Løvås, Håvard Snefjellå; Johnsen, Geir; Koestner, Daniel Warren; Sætre, Camilla; Hamre, Børge. (2024) Pixelwise immersion factor calibration for underwater hyperspectral imaging instruments. Optics Express
Academic article
Dumke, Ines; Ludvigsen, Martin; Ellefmo, Steinar Løve; Søreide, Fredrik; Johnsen, Geir; Murton, Bramley J.. (2018) Underwater Hyperspectral Imaging Using a Stationary Platform in the Trans-Atlantic Geotraverse Hydrothermal Field. IEEE Transactions on Geoscience and Remote Sensing
Academic article
Jouenne, Fabien; Eikrem, Wenche; Gall, F Le; Marie, Dominique; Johnsen, Geir; Vaulot, Daniel. (2011) Prasinoderma singularis sp. nov. (Prasinophyceae, Chlorophyta), a Solitary Coccoid Prasinophyte from the South-East Pacific Ocean. Protist
Academic article
Bakken, Torkild; Evertsen, Jussi; Johnsen, Geir. (2008) Vitenskapelig dykking - behov for endringer i forskriften. Dykkenytt : informasjonsorgan for dykkeindustrien
Professional article
Johnsen, Geir; Søreide, Fredrik. (2010) Underwater hyperspectral imaging of marine mineral deposits. Underwater Mining meeting Institute (UMI)
Conference abstract
Jones, Alun; Utne, Ingrid Bouwer; Johnsen, Geir. (2025) Towards ecological integration into socio-technical risk assessment: A multidisciplinary system-theoretic approach. Ocean Engineering
Academic article
Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa; Hop, Haakon; Renaud, Paul E.; Smedsrud, Lars Henrik; Stige, Leif Christian. (2023) Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene
Academic literature review
Volent, Z; Johnsen, Geir; Sigernes, Fred. (2009) Microscopic hyperspectral imaging used as a bio-optical taxonomic tool for micro- and macroalgae. Applied Optics
Academic article
Carlsen, BP; Johnsen, Geir; Berge, Jørgen; Kuklinski, P. (2007) Biodiversity patterns of macro-epifauna on different lamina parts of Laminaria digitata and Saccharina latissima collected during spring and summer 2004 in Kongsfjorden, Svalbard. Polar Biology
Academic article
Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir; Kopec, Tomasz Piotr; Porter, Marie; Mckee, David. (2022) Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems
Academic article
Millie, David; Schofield, Oscar; Kirkpatrick, Gary J.; Johnsen, Geir; Evens, Tim J.. (2002) Using absorbance and fluorescence spectra to discriminate microalgae. European journal of phycology
Academic article
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2005) Ocean temperature oscillations enable reappearance of blue mussels Mytilus edulis in Svalbard after 1000 year absence. Marine Ecology Progress Series
Academic article
Bakken, Sivert; Luis, Kelly; Johnsen, Geir; Johansen, Tor Arne. (2023) Evaluating hyperspectral Secchi depth retrieval through hybrid modeling and regression. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Academic article
Volent, Z; Johnsen, Geir; Sigernes, Fred. (2007) Kelp forest mapping by use of airborne hyperspectral imager. Journal of Applied Remote Sensing
Academic article
Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir; Bones, Atle M.; Brembu, Tore. (2013) Molecular and photosynthetic responses to prolonged darkness and subsequent acclimation to re-illumination in the diatom Phaeodactylum tricornutum. PLOS ONE
Academic article
Cronin, Heather; Cohen, Jonathan H.; Berge, Jørgen; Johnsen, Geir; Moline, Mark A.. (2016) Bioluminescence as an ecological factor during high Arctic polar night. Scientific Reports
Academic article
Hovland, Erlend Kjeldsberg; Hancke, Kasper; Alver, Morten; Drinkwater, Kennneth F.; Høkedal, Jo; Johnsen, Geir; Moline, Mark A.; Sakshaug, Egil. (2012) Optical impact of an Emiliania huxleyi bloom in the frontal region of the Barents Sea. Journal of Marine Systems
Academic article
Hancke, Kasper; Hovland, Erlend Kjeldsberg; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark A.; Sakshaug, Egil. (2012) Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance. Journal of Marine Systems
Academic article
Chauton, Matilde Skogen; Optun, Odd Inge; Bathen, F. T; Volent, Z.; Gribbestad, Ingrid S.; Johnsen, Geir. (2003) HR MAS 1H NMR spectroscopy analysis of whole cells of marine microalgae. Marine Ecology Progress Series
Academic article
Figueroa, F. L.; Escassi, L.; Perez-Rodriguez, E.; Korbee, N.; Johnsen, Geir. (2003) Effects of the irradiance in the short-term on accumulation of mycosporine like amino acids in sun and shade species of the red algal genus Porphyra. Photochemistry and Photobiology
Academic article
Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL End User Requirement evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
Academic article
Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; Torre, Pedro R. De La; Nornes, Stein Melvær; Singh, Hanumant; Sørensen, Asgeir Johan; Daase, Malin; Johnsen, Geir. (2018) Use of an autonomous surface vehicle reveals small-scale diel vertical migrations of zooplankton and susceptibility to light pollution under low solar irradiance. Science Advances
Academic article
Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Erratum to: Glowing in the dark: discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
Corrigendum
Moreira Fragoso, Glaucia; Poulton, Alex J.; Yashayaev, Igor M.; Head, Erica J.H.; Johnsen, Geir; Purdie, Duncan A.. (2018) Diatom biogeography from the Labrador Sea revealed through a trait-based approach. Frontiers in Marine Science
Academic article
Evertsen, Jussi; Burghardt, Ingo; Johnsen, Geir; Wägele, Heike. (2007) Retention of functional chloroplasts in some sacoglossans from the Indo-Pacific and Mediterranean. Marine Biology
Academic article
Gileptis, Laura; Johnsen, Geir; Moxness, Helge; Norwich, Inger; Vangen, Steffen. (2002) Modul for mønstergjenkjenning/klassifisering i DynamicImager ved bruk av backpropagation-algoritmen. Piksel'n : Organ for NOBIM (Norsk forening for bildebehandling og mønstergjenkjenning)
Academic article
Grzymski, J.; Johnsen, Geir; Sakshaug, Egil. (1997) The significance of intracellular self-shadingon the bio-optical properties of brown, red and green macroalgal species. Journal of Phycology
Academic article
Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir; Brembu, Tore; Bones, Atle M.. (2014) System responses to equal doses of photosynthetically usable radiation of blue, green, and red light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Academic article
Günzel, Leonard Florian Tom; Osanen, Janina Emilia; Løvås, Håvard Snefjellå; Johnsen, Geir; Ortiz, Alberto García; Ludvigsen, Martin. (2025) Using Underwater Hyperspectral Imaging to Increase Feature Detection and Improve Under-Ice Navigation. IEEE Underwater Technology (UT)
Academic article
Vernet, M.; Mitchell, B.G.; Sakshaug, Egil; Johnsen, Geir; Iturriaga, R.; Wassmann, P.. (1996) Evidence for a novel pigment with in vivo absorption maximum at 708 nm associated with Phaeocystis cf. pouchetii blooms. Marine Ecology Progress Series
Academic article
Johnsen, Geir; Sakshaug, Egil. (1995) Light harvesting in bloom-forming marine phytoplankton: species-specificity and photoadaption. Scientia Marina
Academic article
Millie, D.; Schofield, O. M.; Kirkpatrick, G. J.; Johnsen, Geir; Tester, P. A.; Vinyard, B. T.. (1997) Phytoplankton pigments and absorption spectra as potential bio-markers for harmful algal blooms: A case study of the Florida red-tide dinoflagellat Gymnodinium breve. Limnology and Oceanography
Academic article
Grzymski, J.; Johnsen, Geir; Sakshaug, Egil. (1997) The significance of intracellular self-shading on the bio-optical properties of brown, red and green macroalgal species. Journal of Phycology
Academic article
Overrein, Martin Molberg; Tinn, Phil; Aldridge, David; Johnsen, Geir; Moreira Fragoso, Glaucia. (2024) Biomass estimations of cultivated kelp using underwater RGB images from a mini-ROV and computer vision approaches. Frontiers in Marine Science
Academic article
Ludvigsen, Martin; Sortland, Bjørn; Johnsen, Geir; Singh, Hanumant. (2007) Applications of Geo-Referenced Underwater Photo Mosaics in Marine Biology and Archaeology. Oceanography
Academic article
Berge, Jørgen; Båtnes, Anna Solvang; Johnsen, Geir; Blackwell, Susan; Moline, Mark A.. (2012) Bioluminescence in the high Arctic during the polar night. Marine Biology
Academic article
Geoffroy, Maxime; Langbehn, Tom Jasper; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Bris, Arnault Le; Fisher, Jonathan A. D.; Daase, Malin; Mckee, David; Cohen, Jonathan H.. (2021) Pelagic organisms avoid white, blue, and red artificial light from scientific instruments. Scientific Reports
Academic article
Johnsen, Geir; Eikrem, W.; Dalløkken, R.; Aure, J.; Skjoldal, H. R.. (1998) Physiology and environmental conditions during a toxic blooms of Chrysochromulina leadbeateri Prymnesiophyceae. Journal of Phycology
Academic article
Johnsen, Geir. (1991) Proceedings from a scientific working meeting. Fisken og Havet
Academic article
Nilssen, Ingunn; Santos, Francisco Dos; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo M.; Eide, Ingvar; Figueiredo, Marcia AO; Johnsen, Geir; Johnsen, Ståle. (2015) Assessing the potential impact of water-based drill cuttings on deep water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
Academic article
Berge, Jørgen; Geoffroy, Maxime; Johnsen, Geir; Cottier, Finlo Robert; Bluhm, Bodil; Vogedes, Daniel Ludwig. (2016) Ice-tethered observational platforms in the Arctic Ocean pack ice. IFAC-PapersOnLine
Academic article
Ostaszewska, Kaja; Balazy, Piotr; Berge, Jørgen; Johnsen, Geir; Staven, Robert. (2017) Seabirds during Arctic Polar Night: underwater observations from Svalbard archipelago, Norway. Waterbirds (De Leon Springs, Fla.)
Academic article
Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole; Ludvigsen, Martin; Johnsen, Geir; Sousa, João; Rajan, Kanna. (2020) Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer. Oceanography
Academic article
Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John; Olsen, Lasse Mork; Kauko, Hanna M.; Bailey, Allison; Chierici, Melissa. (2017) Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic. Scientific Reports
Academic article
Moreira Fragoso, Glaucia; Poulton, Alex James; Pratt, Nicola Jane; Johnsen, Geir; Purdie, Duncan Alastair. (2019) Trait-based analysis of subpolar North Atlantic phytoplankton and plastidic ciliate communities using automated flow cytometer. Limnology and Oceanography
Academic article
Liefmann, Stephanie; Järnegren, Johanna; Johnsen, Geir; Murray, Fiona. (2018) Eco-physiological responses of cold-water soft corals to anthropogenic sedimentation and particle shape. Journal of Experimental Marine Biology and Ecology
Academic article
Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan; Nilssen, Ingunn. (2015) Enabling technology for Arctic research. Pan European Networks: Science and Techology Magazine
Academic literature review
Nilssen, Ingunn; dos, Francisco Santos; Coutinho, Ricardo; Gomes, Natalia; Montenegro, Marcelo Cabral; Eide, Ingvar; Figueiredo, Marcia; Johnsen, Geir; Johnsen, Ståle. (2015) Assessing the potential impact of water-based drill cuttings on deep-water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
Academic article
Rodriguez, Francisco; Garrido, J.L.; Sabrino, C; Johnsen, Geir; Riobo, P; Franco, J; Aamot, Inga; Ramilo, I; Sanz, N; Kremp, Anke. (2015) Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae). Environmental Microbiology
Academic article
Dona, Angela; Evertsen, Jussi; Johnsen, Geir. (2022) The role of parapodia and lack of photoacclimation in kleptoplasts of the sacoglossan sea slug Plakobranchus ocellatus. Coral reefs
Academic article
Bakken, Sivert; Henriksen, Marie Bøe; Birkeland, Roger; Langer, Dennis David; Oudijk, Adriënne Esmeralda; Berg, Simen; Pursley, Yeshi Jampel; Garrett, Joseph Landon; Gran-Jansen, Fredrik; Honoré-Livermore, Evelyn. (2023) HYPSO-1 CubeSat: First Images and In-Orbit Characterization. Remote Sensing
Academic article

Artistic productions

Snyder, Mike; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2021) “Into the dark” documentary by Mike Snyder following Jørgen Berge (UiT), Geir Johnsen (NTNU) and David McKee (Uni Strathclyde) during Polar Night marine ecology work.
Film
Aarekol, Lena; Johnsen, Geir; Berge, Jørgen. (2015) Polarnatt. Liv og lys i mulm og mørke Polarnighth. Life and death in dead of night.
Exhibition
Berge, Jørgen; Johnsen, Geir. (2020) Polar Night exhibition in Karelia (Petrozavodsk, Russia): 03.03 – 03.04.2020.
Exhibition
Tandberg, Anne Helene S.; Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) POLARNATT - liv og lyst i mulm og mørke.
Exhibition
Gätzschmann, Per; Hårsaker, Karstein; Johnsen, Geir; Leite, Stein Roar; Pedersen, Solbjørg; Sørumgård, Marit. (2016) Nye oppdagelser i polarnatta - video.
Exhibition
Berge, Jørgen; Johnsen, Geir; Tandberg, Anne helene. (2017) Polar night - Life and light in the dead of night.
Exhibition
Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Sørumgård, Marit; Sandbakk, Elin; Johnsen, Tobias Kvendseth. (2016) Polarnatt/Polar Night - ny utstilling med nyheter fra 2015-2016.
Exhibition
Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) Life and light in the dead of night.
Exhibition

Books

Reigstad, Marit; Johnsen, Geir; Sundfjord, Arild. (2025) The Barents Sea system - Gateway to the changing Arctic. Fagbokforlaget
Anthology
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit M.. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag
Non-fiction monograph
Sakshaug, Egil; Johnsen, Geir. (2005) Algal cultures, Analogues of Blooms and Applications. Multi-Science Publishing
Anthology
Syvertsen, E.; Hegseth, E; Johnsen, Geir; Sakshaug, Egil; Gulliksen, B; Lønne, O. J; Aarseth, A. (1992) Livet i isen (The life in the ice). In Økosystem Barentshavet. [Mangler utgivernavn]
Non-fiction monograph
Sakshaug, Egil; Kristiansen, S; Syvertsen, E; Eilertsen, H. C; Gilstad, M; Hegseth, E. N; Hewes, C; Holm-Hansen, O; Johnsen, Geir; Mitchell, B. G. (1992) Planktonalger (Phytoplankton). In Økosystem Barentshavet. [Mangler utgivernavn]
Non-fiction monograph
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2012) Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography. Cambridge University Press
Anthology
Sakshaug, E.; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag
Textbook
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag
Anthology
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press
Anthology
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Polar night marine ecology - life and light in the dead of night. Springer
Anthology

Part of book/report

Sakshaug, E.; Johnsen, Geir; Kristiansen, Svein; Quillfeldt, C.v.; Rey, F.; Slagstad, D.; Thingstad, F.. (2009) Phytoplankton and primary production.
Academic chapter
Johnsen, Geir; Volent, Z; Sakshaug, E.; Sigernes, Fred; Pettersson, L.H.. (2009) Remote sensing in the Barents Sea.
Academic chapter
Johnsen, Geir; Volent, Z.; Tangen, K.; Sakshaug, Egil. (1997) Time series of harmful and benign phytoplankton blooms in northwest European waters using the Seawatch buoy system.
Academic chapter
Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik; Moline, Mark A.. (2014) Managing data from multiple sensors in an interdisciplinary research cruise.
Academic chapter
Sakshaug, E.; Johnsen, Geir; Volent, Z. (2009) Light.
Academic chapter
Johnsen, Geir; Samset, O.; Sakshaug, Egil. (1998) Bio-optical classification of potential harmful chlorophyll c -containing prymnesiophyte blooms in Scandinavian water.
Academic chapter
Pavlov, Alexey K.; Leu, Eva; Hanelt, Dieter; Bartsch, Inka; Karsten, Ulf; Hudson, Stephen; Gallet, Jean-Charles; Cottier, Finlo Robert; Cohen, Jonathan H.; Berge, Jørgen. (2019) The Underwater Light Climate in Kongsfjorden and Its Ecological Implications.
Academic chapter
Johnsen, Geir; Moline, Mark; Pettersson, Lasse H.; Pinckney, J. L.; Pozdnyakov, Dmitry; Egeland, Einar Skarstad; Schofield, O. M.. (2011) Optical monitoring of phytoplankton bloom pigment signatures.
Academic chapter
Zolich, Artur Piotr; Faltynkova, Andrea; Johnsen, Geir; Johansen, Tor Arne. (2022) Portable Catamaran Drone - an uncrewed sampling vehicle for micro-plastics and aquaculture research.
Academic chapter
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Introduction.
Introduction in anthology
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr. (2020) Light in the Polar Night.
Academic chapter
Zolich, Artur Piotr; Torre, Pedro R. De La; Rodwell, Shane; Geoffroy, Maxime; Johnsen, Geir; Berge, Jørgen. (2018) An ice-tethered buoy for fish and plankton research.
Academic chapter
Johnsen, Geir; Leu, Eva; Gradinger, Rolf. (2020) Marine Micro- and Macroalgae in the Polar Night.
Academic chapter
Berge, Jørgen; Johnsen, Geir; Last, Kim; Cohen, Jonathan H.; McKee, David. (2024) Light in polar regions.
Non-fiction chapter
Berge, Jørgen; Johnsen, Geir. (2020) Life and Light at the Dead of Night.
Academic chapter
Sakshaug, Egil; Johnsen, Geir. (2005) Absorption, fluorescence excitation and photoacclimation in phytoplankton.
Academic chapter
Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H.. (2020) Operative Habitat Mapping and Monitoring in the Polar Night.
Academic chapter
Johnsen, Geir; Volent, Zsolt; Dierssen, Heidi; Pettersen, Ragnhild; Ardelan, Murat Van; Søreide, Fredrik; Fearns, Peter; Ludvigsen, Martin; Moline, Mark A.. (2013) Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties.
Academic chapter
Quillfeldt, Cecilie H. von; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik. (2009) Ice algae.
Academic chapter
Ludvigsen, Martin; Johnsen, Geir; Lågstad, Petter Arthur; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord.
Academic chapter
Quillfeldt, C.v.; Hegseth, E.N.; Johnsen, Geir; Sakshaug, E.; Syvertsen, E.E.. (2009) Ice algae.
Academic chapter
Sakshaug, Egil; Johnsen, Geir; Kristiansen, Svein; von Quillfeldt, Cecilie; Rey, Francisco; Slagstad, Dag; Thingstad, Frede. (2009) Phytoplankton and primary production.
Academic chapter
Johnsen, Geir; Volent, Zsolt; Sakshaug, Egil; Sigernes, Fred; Pettersson, Lasse H.. (2009) Remote sensing in the Barents Sea.
Academic chapter
Sakshaug, Egil; Johnsen, Geir; Volent, Z.. (2009) Light.
Academic chapter
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Preface.
Introduction in anthology
Llewellyn, Carole A.; Roy, Suzanne; Johnsen, Geir; Egeland, Einar Skarstad; Chauton, Matilde; Hallegraeff, Gustaff; Lohr, Martin; Oster, Ulrike; Porra, Robert J.; Scheer, Hugo. (2011) Perspectives on future directions.
Academic chapter
Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur; Ødegård, Øyvind; Candeloro, Mauro; Nornes, Stein Melvær; Malmquist, Christian. (2015) Underwater vehicles for environmental management in coastal areas.
Academic chapter
von Quillfeldt, Cecilie; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik E.. (2009) Ice algae.
Academic chapter
Brunet, Christophe; Johnsen, Geir; Lavaud, Johan; Roy, Suzanne. (2011) Pigments and photoacclimation processes.
Academic chapter
Johnsen, Geir; Bricaud, Annick; Nelson, Norman; Prézelin, Barbara; Bidigare, Robert. (2011) In vivo bio-optical properties of phytoplankton pigments.
Academic chapter
Johnsen, Geir; Volent, Z.; Tangen, K.; Sakshaug, Egil. (1997) Time series of harmful and benign phytoplankton blooms in northwest European waters using the Seawatch buoy system.
Academic chapter

Report

Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2007) Bio-optical properties and spectral attenuation of photosynthetically available radiation: relation to primary productivity and phytoplankton composition. In Proceedings from Arctic Frontiers: balancing human use and ecosystem protection. UiT Norges arktiske universitet
Research report
Johnsen, Geir; Volent, Zsolt; Sigernes, F.; Berge, Jørgen; Hovland, Erlend Kjeldsberg; Sakshaug, Egil. (2007) Local hyperspectral imaging of ocean colour from tethered balloons in the Arctic. In Proceedings from Arctic Frontiers: Balancing human use and ecosystem protection. UiT Norges arktiske universitet
Research report
Johnsen, Geir. (2001) SISCAL End User Requirement Satellite-based Information System on Coastal Areas and Lakes. Information Society Technologies Programme funded by the European Comm
Research report
Berge, Jørgen; Schander, C; Pampanin, D.M.; Johnsen, Geir. (2007) The past, present and future of the Mytilus edulis population on Svalbard. In Proceedings from Arctic Frontiers: Balancing human use and ecosystem protection. UiT Norges arktiske universitet
Research report
Johnsen, Geir; Volent, Zsolt; Sigernes, F.. (2007) Fine scale studies using hyper-spectral remote sensing. ESSAS Meeting in Marine Arctic Climate
Research report
Eldevik, Tor; Reigstad, Marit; Falck, Eva; Gerland, Sebastian; Jentoft, Sissel; Johnsen, Geir; Lindstrøm, Ulf; Rasmussen, Tine Lander; Røed, Lars Petter; Wassmann, Paul. (2014) Arven efter Nansen. Forskningsplan for det sentrale og nordlige Barentshavet. UiT Norges arktiske universitet
Research report
Hancke, Torunn Beate; Johnsen, Geir. (2004) SISCAL processor evaluation document. www.siscal.net
Research report
Johansen, Torunn Beate; Johnsen, Geir. (2002) End User requirement evaluation document. [Mangler utgivernavn]
Research report
Johansen, Torunn Beate; Johnsen, Geir. (2002) End User Requirements document. [Mangler utgivernavn]
Research report
Roy, Suzanne; Egeland, Einar Skarstad; Johnsen, Geir; Llewellyn, Carole; Wright, Simon. (2006) Report of a Workshop on a Follow-Up Volume of the Book "Phytoplankton Pigments in Oceanography". Scientific Committee on Oceanic Research
Research report

Student thesis or dissertation

Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Valle, Kristin Collier. (2014) Photoacclimation mechanismsand light responses in marine micro- and macroalgae. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Nymark, Marianne. (2013) Light responses in the marine diatom Phaeodactylum tricornutum. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Kauko, Hanna Maria; Johnsen, Geir; Assmy, Phillipp. (2018) Light response and acclimation of macroalgae in a changing Arctic. NTNU
Doctoral thesis
Strømsholm, Jørgen; Johnsen, Geir; Ludvigsen, Martin. (2018) Eyes beneath the surface - using a miniROV to reveal the habitat and dietary choices of the European shag. Norges teknisk-naturvitenskapelige universitet
Master thesis
Alvsvåg, Dora Marie; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Berge, Jørgen. (2017) Mapping of a seagrass habitat in Hopavågen, Sør-Trøndelag, with the use of an Autonomous Surface Vehicle combined with optical techniques. Norges teknisk-naturvitenskapelige universitet
Master thesis
Båtnes, Anna Solvang; Johnsen, Geir. (2008) Trophic interaction between little auks and their zooplankton prey in a high Arctic fjord based on lipid analyses. NTNU, Institutt for biologi
Master thesis
Johnsen, Geir; Nepstad, Ina. (2009) Cloning and characterisation of interleukin-6 and interleukin-11b in Atlantic halibut (Hippoglossus hippoglossus). NTNU, Institutt for biologi
Master thesis
Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2014) Elemental Composition in various Marine Brown, Green and Red Macroalgae with respect to Season and Tissue-Age. Norges teknisk-naturvitenskapelige universitet
Master thesis
Elvestrand, Jostein; Johnsen, Geir; Sneli, Jon-Arne. (2007) Morphometry and patterns of growth in Acesta excavata (Bivalvia: Limidae) from the Trondheimsfjord, Norway. NTNU, Institutt for biologi
Master thesis
Førde, Hedda; Grant, Stephen Denis; Viljanen, Martta; Majaneva, Sanna Kristiina; Johnsen, Geir. (2024) Glow and know – Evaluating the Potential of Spectral Bioluminescence as a Tool for Zooplankton Identification in situ. Norges teknisk-naturvitenskapelige universitet
Master thesis
Five, Taran; Majaneva, Sanna Kristiina; Viljanen, Martta; Grant, Stephen Denis; Johnsen, Geir. (2024) Studying Behavioral Responses to Bioluminescence in Zooplankton. Norges teknisk-naturvitenskapelige universitet
Master thesis
Hovland, Erlend Kjeldsberg; Sakshaug, Egil; Johnsen, Geir. (2007) Tracing Coccolithophorid Blooms in the Barents Sea Using MODIS Level-3 Imagery. NTNU, Institutt for biologi
Master thesis
Lund, Lene; Johnsen, Geir; Bakken, Torkild; Gabrielsen, Tove. (2014) Morphological Diversity in Laminaria digitata: -different Species or different Phenotypes?. Norges teknisk-naturvitenskapelige universitet
Master thesis
Johnsen, Geir; Aberle-Malzahn, Nicole; Fragoso, Glaucia; Thu, Maren. (2022) Phytoplankton spring bloom mapping in coastal areas using Autonomous Underwater Vehicle (AUV) and optical approaches. Norges teknisk-naturvitenskapelige universitet
Master thesis
Sylling, Guro; Thingstad, Per Gustav; Johnsen, Geir. (2006) Marin bunndyrfauna (Gastropoda, Bivalvia) - Konsekvenser av åpning av veifylling over Ramsarområdet Tautrasvaet. NTNU, Institutt for biologi
Master thesis
Nøland, Annecken; Johnsen, Geir; Aberle-Malzahn, Nicole. (2022) Autonomous Underwater Vehicle (AUV) based study of zooplankton communities, using a silhouette camera and artificial intelligence. Norges teknisk-naturvitenskapelige universitet
Master thesis
Fjærtoft, Kaja Lønne; Bakken, Torkild; Johnsen, Geir; Ludvigsen, Martin. (2018) Macroalgal detritus: Physical variables and impacts on the benthic macrofaunal community. Norges teknisk-naturvitenskapelige universitet
Master thesis
Søreng, Marte Opsahl; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad; Gryte, Kristoffer. (2022) Mapping of Zostera habitat in the Sublittoral Zone using Underwater Hyperspectral Imaging and Unmanned Surface Vehicle. Norges teknisk-naturvitenskapelige universitet
Master thesis
Olsen, Lasse Mork; Johnsen, Geir. (2005) Interactions between marine osmo- and phagotrophs in different physicochemical environments. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Carlsen, Beth Paludan; Johnsen, Geir. (2006) Makroepifauna associeret med Laminaria digitata og L. saccharina, Svalbard. NTNU, Institutt for biologi
Master thesis
Mynors, Julie; Johnsen, Geir; Wernand, Marcel; Volent, Zsolt. (2017) Ocean Colour and Phytoplankton Dynamics - An examination of the Forel-Ule scale in a modern context. Norges teknisk-naturvitenskapelige universitet
Master thesis
Kleiven, Mona; Johnsen, Geir. (2007) Pigmentation in Halocynthia pyriformis from Isfjorden, Spitsbergen. NTNU, Institutt for biologi
Master thesis
Kvernvik, Ane Cecilie; Johnsen, Geir; Aamot, Inga. (2014) How Lamina Age Influence Photosynthetic Response to Light Variations in Saccharina latissima. Norges teknisk-naturvitenskapelige universitet
Master thesis
Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin; Hansen, Roy Edgar; Maarleveld, Thijs. (2018) Towards Autonomous Operations and Systems in Marine Archaeology. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Pettersen, Ragnhild; Johnsen, Geir. (2007) Phytoplankton systematics and pigmentation in the Arctic. NTNU, Institutt for biologi
Master thesis
Stübner, Eike; Johnsen, Geir. (2007) Biogeographical distribution of temperate vs. Arctic benthic species around Svalbard. NTNU, Institutt for biologi
Master thesis
Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2021) Underwater Hyperspectral Imaging as a Tool for Benthic Habitat Mapping. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Marnor, Camilla Mult; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Mapping distribution patterns of brittle stars using ROV-based imaging. Norges teknisk-naturvitenskapelige universitet
Master thesis
Johnsen, Geir. (1994) Light Harvesting and Utiliation in Marine Phytoplankton: Species-Specific and Photoadaptive Responses. Dr. Scient. Thesis in Marine Botany, University of Trondheim
Doctoral thesis
Ringvold, Halldis; Johnsen, Geir; Andersen, Tom. (2021) Studies on Echinodermata from the NE Atlantic Ocean - Spatial distribution and abundance of Asteroidea, including taxonomic and molecular studies on Crossaster and Henricia genera - Value-chain results, including test fishery, biology, market and nutritional analysis on Parastichopus tremulus (Holothuroidea) from the Norwegian coast. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Chauton, Matilde Skogen; Johnsen, Geir; Sakshaug, Egil. (2005) Nuclear Magnetic Resonance spectroscopy of marine microalgae: Metabolic profiling and species discrimination from High-resolution Magic Angle Spinning NMR analysis of whole-cell samples. NTNU, Institutt for biologi
Doctoral thesis
Hancke, Kasper; Johnsen, Geir. (2007) Photosynthetic responses as a function of light and temperature: Field and laboratory studies on marine microalgae. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Fremstedal, Ane Sofia Viset; Bruheim, Per; Sletta, Håvard; Johnsen, Geir. (2012) Utvikling og optimalisering av protokoll for massespektrometrisk metabolsk profilering av adherente humane celler. Norges teknisk-naturvitenskapelige universitet
Master thesis
Liefmann, Stephanie; Johnsen, Geir; Järnegren, Johanna. (2016) Eco-physiological responses of cold-water corals to anthropogenic sedimentation and particle shape. Norges teknisk-naturvitenskapelige universitet
Master thesis
Bjørdalsbakke, Lise Kristin; Johnsen, Geir; Bakken, Torkild; Berge, Jørgen. (2011) Population structure, parasitism and prey preference in Sclerocrangon boreas and S. ferox, Svalbard. Norges teknisk-naturvitenskapelige universitet
Master thesis
Belseth, Elen; Johnsen, Geir; Berge, Jørgen. (2012) Eco-physiology of the Arctic kelp Laminaria solidungula. NTNU Master thesis
Master thesis
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Sakshaug, Egil; Folkestad, Are. (2012) Bio-optics and Ecology in Emiliania huxleyi Blooms: Field and Remote Sensing Studies in Norwegian Waters. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Håpnes, Sverre Julian; Johnsen, Geir; Ludvigsen, Martin; Lågstad, Petter Arthur. (2016) Mapping of demersal fish and benthos by AUV equipped with optical and acoustic imagers at 600 m depth in Trondheimsfjorden. NTNU MSc
Master thesis
Graham, Lisa Kristine Hernandez; Johnsen, Geir; Christensen-Dalsgaard, Signe. (2019) A pilot study assessing drones for mapping and monitoring of European shags. Norges teknisk-naturvitenskapelige universitet
Master thesis
Nornes, Stein Melvær; Sørensen, Asgeir Johan; Ludvigsen, Martin; Johnsen, Geir; Schjølberg, Ingrid; Ånonsen, Kjetil Bergh. (2018) Guidance and Control of Marine Robotics for Ocean Mapping and Monitoring. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Nevstad, Malin Bø; Johnsen, Geir; Bakken, Torkild; Larsen, Martin Kvisvik; Mogstad, Aksel Alstad. (2022) Use of different imaging systems for ROV-based mapping of complex benthic habitats. Norges teknisk-naturvitenskapelige universitet
Master thesis
Krohn-Pettersen, Gitte; Majaneva, Sanna Kristiina; Viljanen, Martta; Grant, Stephen Denis; Johnsen, Geir. (2023) Blinks in the dark - Detecting and characterizing flash kinetics of bioluminescence for in situ species recognition of zooplankton. Norges teknisk-naturvitenskapelige universitet
Master thesis
Pettersen, Ragnhild; Johnsen, Geir. (2013) Identification of Marine Organisms using Chemotaxonomy and Hyperspectral Imaging. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan. (2013) The use of side scan and synthetic aperture sonar mounted on autonomous underwater vehicles for biological habitat mapping. NTNU
Master thesis
Svendsen, Thea; Majaneva, Sanna Kristiina; Majaneva, Markus; Båtnes, Anna Solvang; Johnsen, Geir. (2023) The usability of eDNA to identify and quantify zooplankton communities. Norges teknisk-naturvitenskapelige universitet
Master thesis
Ingrid, Hansen; Johnsen, Geir; Sørensen, Asgeir Johan. (2013) Optical Mapping of Cold-water Corals in Trondheimsfjorden and Svalbard. NTNU
Master thesis
Båtnes, Anna Solvang; Johnsen, Geir. (2013) Light in the dark – the role of irradiance in the high Arctic marine ecosystem during polar night. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
Valle, Kristin Collier; Johnsen, Geir. (2005) Detection of monthly variation in marine red, brown and green macroalgae by means of in situ video, epifluorescence microscopy and numerical digital image analysis. NTNU, Institutt for biologi
Master thesis
Jakobsen, June; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Karlsen, Svein. (2016) The Tautra Cold-Water Coral Reef - Mapping and describing the biodiversity of a cold-water coral reef ecosystem in the Trondheimsfjord by use of multi-beam echo sounding and video mounted on a remotely operated vehicle. Norges teknisk-naturvitenskapelige universitet
Master thesis
Kamilla, Sporsheim; Sporsheim, Kamilla; Johnsen, Geir; Reitan, Kjell Inge; Evertsen, Antii Jussi. (2017) Astaxanthin as a biomarker for fish feed loading in the marine ecosystem. Norges teknisk-naturvitenskapelige universitet
Master thesis
Elde, Anette Cecilie; Johnsen, Geir. (2009) Pigmentation in deep-water corals from the Trondheimsfjord, Norway. NTNU, Institutt for biologi
Master thesis
Thoen, Hanne Halkinrud; Johnsen, Geir. (2009) Pigmentation in the Arctic deep-sea amphipods Eurythenes gryllus and Anonyx sp. Norges teknisk-naturvitenskapelige universitet
Master thesis
Kjeken, John; Johnsen, Geir; Ludvigsen, Martin; Thorsnes, Terje; Lågstad, Petter Arthur. (2017) The growth of benthic organisms in a dumping ground for military bombs and munitions. Norges teknisk-naturvitenskapelige universitet
Master thesis
Johnsen, Geir; Sandbu, Marthe; Assmy, Philipp. (2017) High Arctic Sea-Ice Algae - The Use of Rapid Light Curves to Assess Photosynthetic Performance of Different Ice-Algal Communities. Norges teknisk-naturvitenskapelige universitet
Master thesis
Paulsen, Emil; Bakken, Torkild; Ramirez-Llodra, Eva; Johnsen, Geir. (2017) Community structure and biodiversity of the benthic megafauna at the inactive hydrothermal site Mohn's Treasure, on the Mohn's Ridge, Arctic Mid-Ocean Ridge (AMOR). Norges teknisk-naturvitenskapelige universitet
Master thesis
Andersen, Hanne Kile; Johnsen, Geir; Bakken, Torkild. (2011) Gastropods Associated with Laminaria hyperborea and Saccorhiza polyschides in a Norwegian Kelp Forest: Comparison of Sampling and In Situ Imaging Techniques. Norges teknisk-naturvitenskapelige universitet
Master thesis
Valle, Kristin Collier; Johnsen, Geir; Bones, Atle M. (2014) Photoacclimation mechanisms and light responses in marine micro- and macroalgae. NTNU
Doctoral thesis
Bjerkvoll, Mikkel; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Aerial & Underwater Hyperspectral Imagery For Shallow Benthic Nature Type Mapping. Norges teknisk-naturvitenskapelige universitet
Master thesis
Hallerud, Charlotte; Johnsen, Geir; Aamot, Inga. (2014) Pigment Composition of Macroalgae from a Norwegian Kelp Forest. Norges teknisk-naturvitenskapelige universitet
Master thesis
Hatlebakk, Maja; Johnsen, Geir; Søreide, Janne. (2014) Effect of lipids and fatty acid composition on success of reproduction in Calanus glacialis. NTNU
Master thesis
Kjerstad, Ingrid; Johnsen, Geir; Sørensen, Asgeir Johan; Bakken, Torkild. (2014) Underwater Imaging and the effect of Inherent Optical Properties on image quality. Norges teknisk-naturvitenskapelige universitet
Master thesis
Førde, Henny; Reitan, Kjell Inge; Johnsen, Geir. (2014) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. NTNU
Master thesis
Hilstad, Kari; Johnsen, Geir. (2005) In situ tidsseriemålinger av lyshøstingsegenskaper og cellekjemi hos marine makroalger i Trondheimsfjorden. NTNU, Institutt for biologi
Master thesis
Andersson, Ingvild Henriette Kristin; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin. (2017) Bio-optical diversity on cold water coral habitats. Norges teknisk-naturvitenskapelige universitet
Master thesis
Øye, Ane-Marte; Johnsen, Geir. (2009) Photobioreactor time-series of a simulated bloom of Emiliania huxleyi. Norges teknisk-naturvitenskapelige universitet
Master thesis

Teaching

Courses

Outreach

2025

Feature article

Berge, Jørgen; Bakken, Torkild; Heggland, Kristin; Ødegård, Øyvind; Ingulstad, Mats; Thun, Terje; Johnsen, Geir. (2025) Historien om et tre (og dets innbyggere).
Conference lecture

Davidsen, Jan Grimsrud; Friis, Mikkel Emil Lange; Museth, Jon; Barron, Elizabeth Sanna; Ingulstad, Mats; Ødegård, Øyvind; Eikemo, Terje Andreas; Johnsen, Geir; Sørensen, Asgeir Johan; Ødegård, Rune Strand. (2025) Mission Mjøsa. 7. international conference on fish telemetry

2024

Conference poster

García, Laura Catherine Paiba; Johnsen, Geir; Bakken, Torkild. (2024) Biological diversity in the Norwegian basin: insights for the management of deep-sea mining. Nordic OIKOS 2024
Conference lecture

García, Laura Catherine Paiba; Johnsen, Geir; Bakken, Torkild. (2024) The deep-sea: in numbers and pictures (related to deep-sea mining). NTNU Ocean talks
Feature article

Ingulstad, Mats; Bakken, Torkild; Ellefmo, Steinar Løve; Johnsen, Geir; Hagspiel, Verena. (2024) Norge mangler kunnskap om gruvedrift i dyphavet.
Feature article

Ingulstad, Mats; Bakken, Torkild; Johnsen, Geir; Ellefmo, Steinar Løve; Hagspiel, Verena. (2024) Norway needs to know much more before actually mining the deep sea.
Conference lecture

Majaneva, Markus; Viljanen, Martta; Grant, Stephen Denis; Daase, Malin Hildegard Elisabeth; Geoffroy, Maxime; Langbehn, Tom; Johnsen, Geir; Majaneva, Sanna Kristiina. (2024) Illuminating zooplankton diel vertical migration with eDNA metabarcoding in the polar night. The 7th ICES/PICES Zooplankton Production Symposium
Conference poster

Singh, Asmita; Sanchez Puerto, Nicolas; Moreira Fragoso, Glaucia; Garrett, Joseph Landon; Johnsen, Geir; Johansen, Tor Arne; Ardelan, Murat van. (2024) Decoding Oceanic Mysteries: The Observational Pyramid for Insights into the Physical and Biogeochemical Changes in the Remote Polar Oceans. Antarktisseminaret 2024
Conference poster

Singh, Asmita; Sanchez Puerto, Nicolas; Moreira Fragoso, Glaucia; Garrett, Joseph Landon; Johnsen, Geir; Johansen, Tor Arne; Ardelan, Murat van. (2024) Enhancing Remote Polar Ocean Monitoring: Applying the Observational Pyramid for Improved Climate Insights. Digital Life Norway: Research School Conference
Conference poster

Viljanen, Martta; Five, Taran; Daase, Malin Hildegard Elisabeth; Hatlebakk, Maja Karoline Viddal; Johnsen, Geir; Majaneva, Sanna Kristiina. (2024) Species-specific light reactions of Arctic Calanus copepods revealed by AI assisted tracking. 15th International Congress of Neuroethology
Lecture

Singh, Asmita; Sanchez Puerto, Nicolas; Moreira Fragoso, Glaucia; Garrett, Joseph Landon; Johnsen, Geir; Johansen, Tor Arne; Ardelan, Murat van. (2024) The Observational Pyramid: Unravelling the Physical and Biogeochemical Processes in the Remote Polar Oceans. Surface Ocean Lower Atmosphere (SOLAS) conference
Conference poster

Nevstad, Malin Bø; Johnsen, Geir; Bakken, Torkild; Løvås, Håvard Snefjellå. (2024) Using the observational pyramid for mapping of norwegian seagrass habitats. Ocean Optics 2024
Lecture

Finstad, Anders Gravbrøt; Bakken, Torkild; Moreira Fragoso, Glaucia; Johnsen, Geir. (2024) Trondheimsfjorden, hva nå?. Hovedutvalg for natur, klima og beredskap, Trøndelag fylkeskommune
Conference lecture

Majaneva, Markus; Viljanen, Martta; Grant, Stephen Denis; Daase, Malin Hildegard Elisabeth; Geoffroy, Maxime; Langbehn, Tom; Johnsen, Geir; Majaneva, Sanna Kristiina. (2024) Illuminating zooplankton diel vertical migration with eDNA metabarcoding in the polar night. BioStandards
Conference poster

Paiba Garcia, Laura Catherine; Johnsen, Geir; Bakken, Torkild. (2024) Exploring deep-sea benthos in the Greenland and Norwegian Seas: what may be affected by deep-sea mining?. British Ecological Conference 2024
Feature article

Ingulstad, Mats; Bakken, Torkild; Ellefmo, Steinar Løve; Hagspiel, Verena; Johnsen, Geir. (2024) Feil på feil om gruvedrift på havbunnen - Stortingsmeldingen om gruvedrift på havbunnen holder ikke vann.
Conference poster

Viljanen, Martta; Majaneva, Sanna Kristiina; Majaneva, Markus; Daase, Malin Hildegard Elisabeth; Johnsen, Geir; Donner, Kristian; Lindström, Magnus. (2024) Arctic zooplankton in changing marine lightscape. Arctic Frontiers 2024 ACTIONS & REACTIONS
Conference lecture

Bakken, Sivert; Johnsen, Geir; Johansen, Tor Arne. (2024) First Look at Mondrian Forests for Hyperspectral Secchi Depth Estimation. 13th EARSeL Workshop on Imaging Spectroscopy
Conference poster

Viljanen, Martta; Daase, Malin Hildegard Elisabeth; Majaneva, Markus; Donner, Kristian; Lindström, Magnus; Johnsen, Geir; Majaneva, Sanna Kristiina. (2024) Arctic zooplankton in changing marine lightscape. The 7th ICES/PICES Zooplankton Production Symposium 2024

2023

Feature article

Sørensen, Asgeir Johan; Ludvigsen, Martin; Sivertsen, Eirik; Johnsen, Geir; Johansen, Tor Arne. (2023) Hvem skal samle inn, forvalte og ha tilgang til informasjon om havområdene?.
Feature article

Sørensen, Asgeir Johan; Ludvigsen, Martin; Siversten, Eirik; Johnsen, Geir; Johansen, Tor Arne. (2023) Who should collect, manage and have access to data from the oceans?.
Feature article

Sørensen, Asgeir Johan; Ludvigsen, Martin; Sivertsen, Eirik Selnæs; Johnsen, Geir; Johansen, Tor Arne. (2023) Hvem skal samle inn, forvalte og ha tilgang til informasjon om havområdene?.
Feature article

Sørensen, Asgeir Johan; Ludvigsen, Martin; Sivertsen, Eirik Selnæs; Johnsen, Geir; Johansen, Tor Arne. (2023) Hvem skal samle inn, forvalte og ha tilgang til informasjon om havområdene?.
Conference poster

Lange, Benjamin Allen; Cimoli, Emiliano; Johnsen, Geir; Campbell, Karley Lynn; Osanen, Janina; Anhaus, Philipp; Summers, Natalie Maria; Granskog, Mats; Katlein, Christian; Matero, Ilkka. (2023) An Overview of Underwater Hyperspectral Imagery of Sea Ice in the Central Arctic Ocean. the Nansen Legacy Symposium
Conference poster

Hatlebakk, Maja Karoline Viddal; Viljanen, Martta; Grant, Stephen Denis; Johnsen, Geir. (2023) Behavioral Response in Calanus Copepods to Change in Ambient Light in the Polar Night. Nansen Legacy symposium: Towards a new Arctic Ocean - Past, Present, Future
Conference lecture

Geoffroy, Maxime; Langbehn, Tom; McKee, David; Sandbank, Einat; Daase, Malin Hildegard Elisabeth; Vogedes, Daniel Ludwig; Varpe, Øystein; Priou, Pierre; Le Bris, Arnault; Fisher, JA. (2023) Pelagic organisms avoid artificial light from scientific instruments. Svalbard Science Conference
Conference lecture

Geoffroy, Maxime; Langbehn, Tom; Mckee, David; Sandbank, Einat; Daase, Malin Hildegard Elisabeth; Vogedes, Daniel Ludwig; Priou, Pierre; Le Bris, Arnault; Fisher, JA; Cohen, Jonathan H.. (2023) Pelagic organisms avoid white, blue, green, and red artificial light from scientific instruments. ICES Symposium on Fisheries Acoustics
Conference poster

Reigstad, Marit; Gerland, Sebastian; Eldevik, Tor; Kunisch, Erin; Wiedmann, Ingrid; Sundfjord, Arild; Bluhm, Bodil Annikki Ulla Barbro; Li, Camille; Nilsen, Frank; Johnsen, Geir. (2023) The Nansen Legacy project invites you to its upcoming international symposium in November 2023. Alaska Marine Science Symposium
Feature article

Carson, Siri Granum; Munro, Bjoern Jenssen,; Johnsen, Geir; Mason, Arthur. (2023) En bærekraftig fremtid for Svalbard – er utvinning av dyphavsmineraler en del av svaret?.
Conference lecture

Viljanen, Martta; Daase, Malin Hildegard Elisabeth; Hatlebakk, Maja Karoline Viddal; Johnsen, Geir. (2023) Behavioral light responses vary between different species of Arctic zooplankton. Visionarium XXI
Interview

Nordahl, A; Dugstad, L; Magnussen, O; Bakken, JB; Johnsen, Geir. (2023) Laksegriseriet.

2022

Lecture

Zolich, Artur Piotr; Faltynkova, Andrea; Johnsen, Geir; Johansen, Tor Arne. (2022) Portable Catamaran Drone - an uncrewed sampling vehicle for micro-plastics and aquaculture research. MTS/IEEE OCEANS
Conference lecture

Dona, Angela; Evertsen, Jussi; Johnsen, Geir. (2022) Lack of kleptoplast photoacclimation and the role of parapodia in the sacoglossan sea slug Plakobranchus ocellatus. 15th International Coral Reef Symposium
Lecture

Oudijk, Esmée; Hasler, Oliver Kevin; Overaas, H; Marty, Sabine; Williamson, David; Svendsen, T; Berg, Simen; Birkeland, Roger; Halvorsen, D; Bakken, S. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. 2022 12th Workshop on Hyperspectral Imaging and Signal Processing: Evolution in Remote Sensing (WHISPERS)

2021

Interview

Bazilchuk, Nancy; Johnsen, Geir; Berge, Jørgen; Hobbs, Laura; Cohen, Jonathan H.. (2021) Shedding light – on the polar night. By N. Bazilchuk. Krill eyeballs. The werewolf effect. Diel vertical migration. Arctic marine biologists really talk about these things.
Conference lecture

Geoffroy, Maxime; Langbehn, Tom; Varpe, Øystein; Cohen, Jonathan H.; Cottier, Finlo; Last, Kim S; Johnsen, Geir; Mckee, David; Daase, Malin Hildegard Elisabeth; Berge, Jørgen. (2021) In situ experiments reveal behavioral response of marine fish and zooplankton when exposed to artificial light during the Arctic polar night. ICES 2021 Annual Science Conference
Conference lecture

Geoffroy, Maxime; Langbehn, Tom; Varpe, Øystein; Cohen, Jonathan H.; Cottier, Finlo; Last, Kim S; Johnsen, Geir; McKee, David; Daase, Malin Hildegard Elisabeth; Berge, Jørgen. (2021) Behavioral response of marine fish and zooplankton exposed to artificial light during acoustic surveys. Arctic Science Summit Week

2020

Conference lecture

Johnsen, Geir. (2020) Centre of Autonomous Marine Operations & Systems (AMOS) - selcted research activities. PRIME + EELS Ocean Worlds Arctic Collaboration (OWAC) Workshop
Conference lecture

Bakken, Sivert; Wei, J; Lee, Z; Johnsen, Geir; Johansen, Tor Arne; Montoya, J; Subramaniam, Ajit. (2020) Hyperspectral Remote Sensing of the Amazon River Plume. Ocean Science Meeting
Interview

Gibbens, Sarah; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2020) As the Arctic warms, light pollution may pose a new treat to marine life.

2019

Interview

Hanger, MR; Johnsen, Geir. (2019) Ny forskningsstrategi: Vil markere at Svalbard er norsk.
Interview

Aadland, Camilla; Johnsen, Geir. (2019) Denne lusejegeren har vunnet designpris. Bakgrunnshistorie om grunnleggingen av Ecotone og undervanns hyperspektral avbilding.
Conference lecture

Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin; Geoffroy, Maxime; Berge, Jørgen. (2019) Shipwrecks in the Arctic – knowledge gaps illustrated by a case from Svalbard. ArcticNet Anuual Scientific Meeting 2019

2018

Interview

Ludvigsen, Martin; Berge, Jørgen; Sørensen, Asgeir Johan; Johnsen, Geir. (2018) Havets hemmeligheter hentes opp fra dypet.
Lecture

Johnsen, Geir. (2018) Polar night - light as a cue of life. Seminar at Hawaiian Inst of marine biology (HIMB), University of Hawaii at Manoa
Conference lecture

Johnsen, Geir. (2018) Underwater hyperspectral imaging for marine biological applications. Seminar at University of Hawaii at Manoa
Lecture

Johnsen, Geir. (2018) Light as a cue for life - Arctic. Kunstakademiet - invitert foredrag
Interview

Ludvigsen, Martin; Berge, Jørgen; Sørensen, Asgeir Johan; Johnsen, Geir; Schiopca, Francesca. (2018) Light pollution from research ship makes Artic zooplankton return to the deep.
Lecture

Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan. (2018) Marin polarnatt. 30 årsjubileum Vitensenteret i Trondheim
Lecture

Johnsen, Geir. (2018) Light as a cue of life - Arctic. Arktis
Lecture

Johnsen, Geir; Berge, Jørgen. (2018) Polarnatt. Polarnatts seminar med muliggjørende teknologi
Conference lecture

Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan. (2018) Enabling technology fort marine ecology. Conference
Contribution to radio or TV

Berge, Jørgen; Cottier, Finlo; Johnsen, Geir; Kintisch, Eli. (2018) “Thaw” episode 1 of 3 – What melting sea ice means for life in the Arctic.
Interview

Sørensen, Asgeir Johan; Johnsen, Tobias Kvendseth; Johnsen, Geir; Tveter, Nina Elisabeth. (2018) Hvordan høres det ut i havdypet.
Conference lecture

Davies, Emlyn John; Moreira Fragoso, Glaucia; Johnsen, Geir; Ellingsen, Ingrid H.. (2018) Combining optics, imaging and artificial intelligence for in-situ characterisation of complex particle populations. AGU Ocean Sciences
Feature article

Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning - enda en kilde til bekymring.
Feature article

Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning truer livet i Arktis.
Interview

Johnsen, Geir; Hanger, Mari Rian. (2018) Manglende interesse for å bruke Ny Ålesund for å utdanne neste generasjons polarforskere.
Interview

Johnsen, Geir; Hanger, Mari Rian. (2018) Manglende interesse for å bruke Ny Ålesund for å utdanne neste generasjons polarforskere.
Interview

Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Haugan, Idun. (2018) Slik finner ny teknologi skipsvrak på havets bunn.

2017

Interview

Bazilchuk, Nancy Reney; Johnsen, Geir. (2017) Dark lords, werewolves and Indiana Jones in the Polar Night.
Interview

Johnsen, Geir. (2017) Dykker så et merkelig fenomen utenfor Egersund.
Interview

Johnsen, Geir; Ludvigsen, Martin; Thorbjørnsen, Susanna Huneide; Berge, Jørgen; Rapp, Ole Magnus. (2017) Nytt superverktøy finner liv i ishavet.
Conference poster

Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Cottier, Finlo Robert. (2017) First records of Periphylla periphylla in a high Arctic fjord: a newcomer or a returning visitor?. Gordon Reserach Conference in Polar Marine Science
Lecture

Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Cottier, Finlo Robert. (2017) First records of Periphylla periphylla in a high Arctic fjord: a newcomer or a returning visitor?. Gordon Research Seminar in Polar Marine Science
Conference lecture

Berge, Jørgen; Johnsen, Geir; Torre, Pedro De La. (2017) Field activities in Kongsfjorden and relations between ice cinditions, light climate and ecosystem dynamics. Resice project-Arctic 2030 - seminar
Interview

Johnsen, Geir; Sævik, Bjørnar Torvholm. (2017) - Dette er helt fantastisk - Supersjeldent blekksprutfenomen i Ålesund.
Lecture

Geoffroy, Maxime; Berge, Jørgen; Falk-Petersen, Stig; Johnsen, Geir; Hernandez, Nestor Santana; Cusa, Marine Lure Joana; Daase, Malin; Bluhm, Bodil; Graeve, Martin; Cottier, Finlo Robert. (2017) Northward range expansion of boreal species into the Arctic: further evidences from the polar night. ArcticChange conference
Interview

Ludvigsen, Martin; Johnsen, Geir; Meland, Svein Inge. (2017) Laboratorium på bunnen av Trondheimsfjorden.
Interview

Johnsen, Geir. (2017) Runde – reduksjon av sjøfuglbestand.
Feature article

Johnsen, Geir; Christiansen, Hanne H; Ravolainen, Virve; Reymert, Per Kyrre; Jenssen, Eva Therese; Arlov, Thor Bjørn; Dybdahl, Jørn. (2017) Utfordrende natur og sikkerhet på Svalbard.
Interview

Johnsen, Geir. (2017) Unikt forskningsprosjekt ved Runde.
Conference lecture

Johnsen, Geir. (2017) Kunnskapsgenerering, kartlegging og overvåkning I nordområdene med autonome systemer. Norges Teknisk Vitenskapsakademi (NTVA) årsmøte
Interview

Otterlei, Inger; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin; Hareide, Nils Roar; Christensen-Dalsgaard, Signe. (2017) 300 000 sjøfugl er forsvunnet fra Runde.
Conference poster

Kauko, Hanna M.; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey; Mundy, C J; Duarte, Pedro; Fernández-Méndez, Mar; Olsen, Lasse Mork; Hudson, S R; Elliott, A. (2017) Windows in Arctic sea ice – light transmission and ice algal response in a refrozen lead. ESSAS international open science meeting, Tromsø, Norway,
Conference lecture

Johnsen, Geir. (2017) Hyperspectral imaging above and in water – applications. Small Satellite Seminar
Conference lecture

Johnsen, Geir. (2017) Use of enabling technology for marine science applications. SFF AMOS og FFI Seminar
Conference poster

Moreira Fragoso, Glaucia; Davies, Emlyn John; Ellingsen, Ingrid H.; Ludvigsen, Martin; Johnsen, Geir. (2017) Assessing phytoplankton and zooplankton dynamics using optical sensors. Aquafluor II Conference in Sydney
Conference lecture

Johnsen, Geir. (2017) Can novel technologies revolutionise the montoring regime in sea-based aquaculture?. Ocean Week Conference, Trondheim
Conference poster

Zolich, Artur Piotr; Johnsen, Geir; Berge, Jørgen; Hagan, Bernard. (2017) Ny Ålesund light observatory experiment – from polar night to midnight sun. Arctic Change Conference, Quebec City, Canada
Conference poster

Kauko, Hanna M.; Mundy, C J; Granskog, M A; Peeken, Ilka; Johnsen, Geir; Ehn, Jens K.; Assmy, Philipp. (2017) Ice algal pigments in thin Arctic sea ice: Trends and correlation to transmitted irradiance. Gordon research conference on Polar marine sciences, Ventura, USA
Conference lecture

Johnsen, Geir. (2017) Bruk av ny teknologi for marine økosystemobservasjoner i luft og vann. Workshop - planlegging av Runde kartlegging, overvåkning og tokt i juni 2017
Interview

Johnsen, Geir. (2017) Kvifor minkar det med sjøfugl?.
Interview

Johnsen, Geir. (2017) Redusert sjøfuglbestand på Runde.
Interview

Johnsen, Geir. (2017) Om roboter og sjøfugl på Runde.
Conference lecture

Johnsen, Geir; Ludvigsen, Martin; Sørensen, Asgeir Johan. (2017) Enabling technology for marine ecology studies. Official meeting between University of Porto and NTNU
Conference lecture

Johnsen, Geir; Berge, Jørgen; Zolich, Artur Piotr. (2017) . Light observatory in Ny Ålesund. Arctic ABC Seminar at NTNU
Interview

Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin. (2017) Sjøfugl, fisk og teknologi på Runde Miljøsenter.
Conference lecture

Johnsen, Geir. (2017) Polar night – past, present and future – A view for nature management and decision making. The Henningsvær charter, Henningsvær 28-30th Sep 2017.
Conference lecture

Berge, Jørgen; Johnsen, Geir. (2017) Life and light in the dead of night. Science Week in Moscow
Conference lecture

Ludvigsen, Martin; Sørensen, Asgeir Johan; Johnsen, Geir. (2017) Autonomous technology in marine environment mapping and monitoring. Autonomous Vehicles for ocean monitoring
Feature article

Berge, Jørgen; Johnsen, Geir. (2017) Superkommunisten.
Feature article

Berge, Jørgen; Johnsen, Geir. (2017) Om bambus, spøkelseskreps og et Arktis i endring.
Conference lecture

Johnsen, Geir; Moreira Fragoso, Glaucia; Davies, Emlyn John; Sørensen, Asgeir Johan; Ludvigsen, Martin; Berge, Jørgen. (2017) Use of optical sensors to identify, map and monitor phyto- and zooplankton. Arctic change conference, Quebec City, Canada
Conference lecture

Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2017) Use of autonomous platforms in the Arctic. Seminar at Norges Vitenskapsakademi for polarforskning og Norges tekniske vitenskapsakademi.
Feature article

Berge, Jørgen; Johnsen, Geir. (2017) Kunnskapshull om livet i Arktis i mørketiden.

2016

Interview

Ødegård, Øyvind; Johnsen, Geir. (2016) Utforsker havets dyp.
Interview

Kintisch, Eli; Berge, Jørgen; Last, Kim; Cohen, Jonathan; Johnsen, Geir. (2016) Voyage into darkness.
Interview

Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Dark lords, werewolves and Indiana Jones in the polar night.
Interview

Hyman, Randall; Berge, Jørgen; Cohen, Jonathan; Moline, Mark A.; Johnsen, Geir. (2016) In the polar ‘twilight zone,’ these unusual sea creatures outshine the starlight.
Feature article

Berge, Jørgen; Johnsen, Geir; Ludvigsen, Martin; Cohen, Jonathan. (2016) Design for latskap - men med store muligheter.
Interview

Aarskog, Karine Nigar; Ødegård, Øyvind; Johnsen, Geir; Berge, Jørgen. (2016) Undervannsrobot som oppfyller tre ønsker.
Interview

Ødegård, Øyvind; Johnsen, Geir; Berge, Jørgen. (2016) Dark lords, werewolves and Indiana Jones in the polar night.
Interview

Haugstad, Tormod; Erdal, Ivar; Johnsen, Geir. (2016) Kameraet deres «kan bli det nye ekkoloddet». Nå er det norske selskapet i ferd med å lykkes.
Interview

Hyman, Randall; Berge, Jørgen; Johnsen, Geir; Malzahn, Nicole; Cohen, Jonathan. (2016) Floating in the Arctic Darkness.
Interview

Flå, Ellen; Johnsen, Geir. (2016) God morgen Trøndelag - Polarnatt.
Contribution to radio or TV

Sørbø, Kari; Johnsen, Geir. (2016) NRK P1+ Frokostradio - "Liv i Polarnatta".
Feature article

Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Kinderegg i polarnatten.
Interview

Eirik, Palm; Berge, Jørgen; Johnsen, Geir. (2016) Fant dypvannsfisk på grunna.
Interview

Opar, Alisa; Berge, Jørgen; Johnsen, Geir. (2016) Meet the Night Creatures of the Warming Arctic.
Feature article

Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) Opp fra polarnattens mørke.
Interview

Ødegård, Øyvind; Berge, Jørgen; Johnsen, Geir; Støbakk, Torun. (2016) Skrekklarven var båtfolkets mareritt.
Contribution to radio or TV

Johnsen, Geir. (2016) Liv i Polarnatta.
Contribution to radio or TV

Johnsen, Geir. (2016) Nye arter funnet på Svalbard.
Interview

Berge, Jørgen; Kintish, Eli; Ødegård, Øyvind; Johnsen, Geir. (2016) Arctic shipworm discovery alarms archaeologists.
Feature article

Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) A bitter-sweet symphony.
Lecture

Søreide, Janne E.; Gradinger, Rolf; Niehoff, Barbara; Bluhm, Bodil; Gabrielsen, Tove M.; Peeken, Ilka; Johnsen, Geir; Berge, Jørgen. (2016) Arctic Ocean winter ecology – the Big Black Box. 3rd Arctic Observing Summit
Interview

Nornes, Stein Melvær; Johnsen, Geir. (2016) Easier automated visual mapping of biodiversity.
Interview

Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2016) Nye mysterier avdekkes i Polhavet.

2015

Conference lecture

Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur; Candeloro, Mauro; Nornes, Stein Melvær; Malmquist, Christian. (2015) Underwater vehicles for environmental management in coastal areas. OCEANS 2015
Interview

Webb, Jonathan; Berge, Jørgen; Johnsen, Geir. (2015) Arctic ocean's wakeful winter revealed.
Interview

Lingenhöhl, Daniel; Berge, Jørgen; Johnsen, Geir. (2015) Highlife in der Polarnacht.
Conference poster

Vogedes, Daniel Ludwig; Berge, Jørgen; Daase, Malin; Johnsen, Geir; Darnis, Gérald; Last, Kim S.; Moline, Mark A.; Renaud, Paul; Leu, Eva; Morata, Nathalie. (2015) Expect the unexpected - a new perspective and understanding of marine life at high latitudes. Gordon Research Conference and Seminar on Polar Marine Science

2014

Conference lecture

Bones, Atle M.; Nymark, Marianne; Valle, Kristin Collier; Winge, Per; Brembu, Tore; Johnsen, Geir; Hancke, Kasper; Aamot, Inga; Andresen, Kjersti. (2014) System responses to equal doses of photosynthetically usable radiation of blue, green and red light in the diatom Phaeodactylum tricornutum. SEB 2014
Lecture

Johnsen, Geir. (2014) Perspektiv fra en faglig ansatt. Strategiske partnerskap og allianser – hva får vi ut av dem – case NORUS. Internasjonaliseringskonferansen 2014, Trondheim 5-6 mars 2014
Conference lecture

Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2014) Underwater robots & sensors in the Polar night. Worshop in underwater robotics
Conference lecture

Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Use of Underwater Hyperspectral Imager (UHI) in Marine Archaeology. Ocean Optics XXII
Lecture

Johnsen, Geir; Berge, Jørgen. (2014) Varulvene kommer!. Svalbard seminaret
Conference lecture

Johnsen, Geir. (2014) KOMPiS (Kompetanse i Skolen) Biodiversitet - Trondheimsfjorden. Kompetanse i skolen (KOMPiS)
Conference lecture

Johnsen, Geir. (2014) Underwater hyperspectral imagery for seafloor mapping - now and future perspectives. Seminar at Curtin University, Perth Western Australia
Lecture

Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2014) Varulver i polarnatta. NTVA-/NVP-seminar i Trondheim
Conference lecture

Johnsen, Geir; Berge, Jørgen. (2014) "Varulvene kommer". Seminar Norw Academy of Polar Res (NAPR) & Techn Sci (NTVA)
Interview

Candeloro, Mauro; Dukan, Fredrik; Ludvigsen, Martin; Sørensen, Asgeir Johan; Johnsen, Geir; Ekra, Siv Ingrid Skau. (2014) Smarte roboter tar nye bilder av havbunnen.
Interview

Johnsen, Geir; Hansen, Ingrid; Hanssen, Christian. (2014) Dette kameraet kan bli det nye ekkoloddet – Ser flere farger enn det menneskelige øyet.

2013

Conference lecture

Johnsen, Geir; Hansen, Ingrid; Ekehaug, Stefan. (2013) Identification, mapping & monitoring of underwater habitats using Underwater Hyperspectral Imager (UHI) on robots. Workshop on sea bed habitats of environmental concern
Interview

Ødegård, Øyvind; Johnsen, Geir. (2013) "Denne vekker interesse hos NASA og US Navy" innslag på NRK Midtnytt om UHI og arkeologi.
Conference lecture

Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir. (2013) Towards Autonomy in Marine Archaeology. Nordisk Konference for Marinarkæologi
Lecture

Johnsen, Geir. (2013) Trondheimsfjordens hemmeligheter. Kunnskapsbyen
Lecture

Johnsen, Geir. (2013) Trondheimsfjordens hemmeligheter - i dypet. Trondheim Rotary Klub
Lecture

Johnsen, Geir. (2013) Undervannsroboter i Trondheimsfjorden. Forskningsdagene i Trondheim
Conference lecture

Johnsen, Geir. (2013) Marine Arctic environment- a quick overview. Workshop in underwater technology & operations, UNIS 10-12 April 2013
Conference lecture

Johnsen, Geir; Hansen, Ingrid Myrnes; Ekehaug, Stefan. (2013) Identification, mapping and monitoring of underwater habitats using underwater hyperspectral imager on robots. Workshop on Sea Bed Habitats of Environmental Concern 2013
Contribution to radio or TV

Johnsen, Geir; Sørensen, Asgeir Johan. (2013) Koraller i dypet.
Conference lecture

Johnsen, Geir; Ludvigsen, Martin; Sørensen, Asgeir Johan; Moline, Mark A.. (2013) Underwater hyperspectral imagery for identification, mapping and monitoring of bio-geo-chemical features on the sea floor. Blue Photonics 3
Conference lecture

Ludvigsen, Martin; Låge, Petter A.; Johnsen, Geir; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord. OCEANS’13
Interview

NRK, P2; Johnsen, Geir; Berge, Jørgen. (2013) Liv I polarnatten – 14 min Podcast , del 2 av 2.
Interview

NRK, P2; Johnsen, Geir; Berge, Jørgen. (2013) Liv i polarnatten (del 1 av 2) i Ekko.
Conference lecture

Johnsen, Geir; Sørensen, Asgeir Johan. (2013) Ny teknologi for utforskning av havrommet. Årssamling FHL Midtnorsk Havbrukslag
Conference lecture

Johnsen, Geir; Sørensen, Asgeir Johan. (2013) Underwater remote sensing – mapping & monitoring of marine life. Workshop on habitat mapping and time-series in coastal Norway and Svalbard
Conference lecture

Johnsen, Geir; Moline, Mark A.; Ludvigsen, Martin; Berge, Jørgen; Sørensen, Asgeir Johan. (2013) Use of underwater robots and sensors to identify, map, monitor biomass & production in the Arctic. Arctic Frontiers

2012

Conference lecture

Johnsen, Geir; Sørensen, Asgeir Johan. (2012) UHI based mapping of habitats and organisms on the seabed. International workshop on seabed mapping methods and technology
Conference lecture

Båtnes, Anna Solvang; Miljeteig, Cecilie; Berge, Jørgen; Johnsen, Geir. (2012) Light responses of Arctic zooplankton during the polar night. Ocean Optics Conference XXI
Conference lecture

Johnsen, Geir. (2012) Marine biology and TBS- Marine underwater robots & sensors. NTNU Marine Science Seminar
Conference lecture

Johnsen, Geir; Sørensen, Asgeir Johan. (2012) NTNU´s kobling naturvitenskap/teknologi gir nøkkelrolle for havrom-utforskning via NTNU MCD. NTNU Marine coastal development strategiseminar
Lecture

Johnsen, Geir. (2012) Marine undervannsroboter og sensorer til havovervåkning. Luncheseminar Institutt for biologi
Lecture

Johnsen, Geir; Sørensen, Asgeir Johan. (2012) Marine undervannsroboter og sensorer til havovervåkning. Luncheseminar Gløshaugen Akademiske Klubb, NTNU
Conference lecture

Johnsen, Geir; Moline, Mark A.; Berge, Jørgen; Sørensen, Asgeir Johan. (2012) Underwater mapping and monitoring in the Arctic. Workshop in Underwater Technology and operations. Workshop in Underwater Technology and operations
Conference lecture

Johnsen, Geir; Moline, Mark A.; Berge, Jørgen; Schofield, Oscar. (2012) Technology and science development for marine monitoring and ocean observation. Workshop in Underwater Technology and operations
Conference lecture

Hovland, Erlend Kjeldsberg; Dierssen, Heidi; Johnsen, Geir. (2012) Emiliania huxleyi in the Barents Sea. Ocean Optics Conference XXI
Conference lecture

Johnsen, Geir. (2012) In situ and remote sensing of phytoplankton pigments – some examples of detecting pigment-signatures using different platforms and optical sensors. Final PROTOOL meeting at SYKE – “Marine Environmental Monitoring Methods
Conference lecture

Båtnes, Anna Solvang; Berge, Jørgen; Johnsen, Geir; Miljeteig, Cecilie. (2012) In situ light responses of high Arctic Calanus spp. Ocean Optics 2012
Conference lecture

Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik; Moline, Mark A.. (2012) Managing data from multiple sensors in an interdisciplinary research cruise. CAA 2012 (Computer Applications and Quantitative Methods in Archaeology )
Interview

opland, egil M; Johnsen, Geir. (2012) Fjernstyrt ubåt kartlegger fjorden.
Lecture

Johnsen, Geir. (2012) Trondheimsfjordens hemmeligheter – I dypet. Kunnskapsbyen, NTNU
Reader opinion

Gabrielsen, Tove M.; von Quillfeldt, Cecilie; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden.

2011

Conference lecture

Johnsen, Geir. (2011) The use of a underwater hyperspectral imager to map and monitor bio-geo-chemical object of interest on seafloor. Australian Meterological & Oceanographic Society symposium
Conference lecture

Johnsen, Geir. (2011) The use of a underwater hyperspectral imagery to map bio-geo-chemical objects of interest on seafloor. Imaging and Phycics seminar series.
Conference lecture

Johnsen, Geir. (2011) Underwater hyperspectral imaging of Great Barrier Reef corals. Lizard Island Research seminar, Australian Museum
Conference lecture

Lynch, Mervin; Hedley, John; Klonowski, Wojchiech; Slivkoff, Matt; Johnsen, Geir; Fearns, Peter; Marrable, Dan. (2011) Remote sensing of the eutrophic state of coastal waters via phytoplankton functional groups. International Symposium on Remote Sensing of Environment
Conference lecture

Johnsen, Geir. (2011) The use of underwater robotics and underwater hyperspectral imagery to map and monitor marine bio-diversity. School of Biology Sciences seminars
Interview

Johnsen, Geir. (2011) “Nordmøringer I Australia” - Lars Djupegot møter Geir Johnsen i Perth.
Conference lecture

Berge, Jørgen; Moline, Mark; Johnsen, Geir. (2011) NORUS – Research-based educational field studies using new sensors for mapping of water surface, column and sea-floor. Transatlantic Science Week, UC Berkeley
Lecture

Johnsen, Geir. (2011) Romteknologi under havoverflaten – Undervannsroboter med optiske sensorer for deteksjon av bio-geo-kjemiske objekter av interesse. Havforskermøte 2011
Interview

Johnsen, Geir. (2011) For gründerpris? NTNU´s spin-off selskap Ecotone i finalen.
Conference lecture

Moline, Mark A.; Johnsen, Geir; Berge, Jørgen. (2011) Technology Development for marine monitoring and oceran observation – a SiU funded research based educational program between US and Norway. Transatlantic Science Week, UC Berkeley
Interview

Johnsen, Geir. (2011) Som fisken I vannet – forskere fra Nordmøre.
Conference lecture

Johnsen, Geir; Sørensen, Asgeir Johan. (2011) Applied Underwater Robotics Laboratory – A new view of subsea applications. The Society for Underwater Technology (AiUT) and The Australian Hydrographic Society.
Lecture

Johnsen, Geir. (2011) Planktonalger – fra fjernmåling til gener. NATUR 2011, Artsdatabankens konferanse om biologisk mangfold
Conference lecture

Johnsen, Geir; Ardelan, Murat Van. (2011) Underwater monitoring of bio-geo-chemical objects of interest using underwater hyperspectral imagery. Transatlantic Science Week

2010

Conference lecture

Dierssen, Heidi; Johnsen, Geir; Cummings, Molly; Maginnis, Tara; Holt, J.. (2010) Spectral polarized reflectance from skin preparations from four different subtropical fish species. Ocean Optics conference OOXX
Conference lecture

Hovland, Erlend Kjeldsberg; Hancke, Kasper; Høkedal, Jo; Johnsen, Geir; Moline, Mark; Sakshaug, Egil. (2010) An in situ bio-optical study of Emiliania huxleyi in the Barents Sea. Oslo Science Conference (OSC)
Conference lecture

Hancke, Kasper; Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark; Sakshaug, Egil. (2010) The Underwater Light Regime and cDOM across the Polar Front (Barents Sea):With relevance for the Primary Production. Oslo Science Conference (OSC)
Conference poster

Hovland, Erlend Kjeldsberg; Hancke, Kasper; Volent, Zsolt; Johnsen, Geir; Sakshaug, Egil. (2010) cDOM in the Barents Sea. Ocean Optics XX

2009

Conference lecture

Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir; Bones, Atle M.. (2009) En integrert analyse av molekylær akklimatisering til sterkt lys i kiselalgen Phaeodactylum tricornutum. Algesymposium 2009
Conference poster

Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Andresen, Kjersti; Brembu, Tore; Johnsen, Geir; Bones, Atle M.. (2009) Global physiological and expression adaptation to changes in light condition in the diatom Phaeodactylum tricornutum. 45th Contact Meeting of the Norwegian Biochemical Society
Conference lecture

Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Winge, Per; Johnsen, Geir; Bones, Atle M.. (2009) Molecular mechanisms behind acclimation to high light conditions for the marine diatom Phaeodactylum tricornutum. CMB seminar series
Conference poster

Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Østensen, Mari-Ann; Johnsen, Geir; Bones, Atle M.. (2009) Molecular mechanisms behind acclimation to high light conditions for the marine diatom Phaeodactylum tricornutum. Plant Biology 2009
Conference poster

Bones, Atle M.; Valle, Kristin Collier; Hancke, Kasper; Andresen, Kjersti; Brembu, Tore; Johnsen, Geir; Nymark, Marianne. (2009) Mining for genes, proteins, metabolites, nanoscale structures and molecular machinery of marine algae. Bioprosp2009

2008

Conference poster

Evertsen, Jussi; Johnsen, Geir. (2008) A window into endosymbiotic adaptation - from organelle to cell in photosynthetic phycozoans. Norske havforskeres forenings årsmøte
Conference poster

Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combining AUV and hyperspectral imaging in coastal monitoring. Ocean Optics conference
Interview

Johnsen, Geir. (2008) På vannets betingelser (Universitetsavisa).
Interview

Johnsen, Geir; Berge, Jørgen; Thoen, Hanne. (2008) Polhavets piraya.
Contribution to radio or TV

Johnsen, Geir; Zotchev, Sergey. (2008) Svamper mot blodkreft.
Contribution to radio or TV

Johnsen, Geir; Berge, Jørgen; Gabrielsen, Tove M.. (2008) På tokt i polhavet med UNIS.
Contribution to radio or TV

Johnsen, Geir; Berge, Jørgen; Gabrielsen, Tove M.. (2008) Klimaendringer, er de menneskeskapt?.
Contribution to radio or TV

Johnsen, Geir; Berge, Jørgen; Gabrielsen, Tove M.. (2008) Pikoplankton i Polhavet.
Contribution to radio or TV

Johnsen, Geir; Zotchev, Sergey. (2008) Svamper mot blodkreft -NTNUs rolle.
Conference poster

Evertsen, Jussi; Johnsen, Geir. (2008) A window into endosymbiotic adaptation - from organelle to cell in photosynthetic phycozoans. Norske havforskeres forenings årsmøte

2007

Conference poster

Brembu, Tore; Valle, Kristin Collier; Størseth, T.R.; Østensen, Mari-Ann; Bjørk, Camilla; Andresen, Kjersti; Johnsen, Geir; Bones, Atle M.. (2007) The DIABOL project – mining for nanoscale structures and machinery of the diatom silica shell. Nanomat konferanse
Conference lecture

Johnsen, Geir; Sakshaug, Egil. (2007) Application of in vivo fluorescence excitation spectra from different pigment-groups of phytoplankton. AquaFluo
Conference lecture

Johnsen, Geir. (2007) Bruk av nye plattformer til tverrfaglig marin forskning ved NTNU. Havet og Kysten
Conference lecture

Johnsen, Geir. (2007) Makroalgeforskning ved TBS-IBI. Integrate SIP konferanse
Conference lecture

Johnsen, Geir. (2007) Overvåkning, kartlegging av marine ressurser ved hjelp av optikk, akustikk og telemetri. Statoil Hydro
Conference lecture

Johnsen, Geir. (2007) Marine bio-optics. NTNU
Conference lecture

Johnsen, Geir. (2007) Hyperspectral monitoring of ocean colour. VISTA
Conference lecture

Johnsen, Geir; Volent, Zsolt; Sigernes, F.. (2007) Fine scale studies using hyper-spectral remote sensing. ESSAS meeting in marine Arctic climate
Conference lecture

Johnsen, Geir. (2007) Bio-optikk til bruk i fjernmåling og in situ detektering av forskjellige biologiske komponenter i Trondheimsfjorden. Marin kystutvikling
Conference poster

Hancke, Torunn Beate; Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2007) Rate of O2 production from PAM fluorescence: Testing three bio-optical approaches against measured O2 production rate. AquaFluo Conference
Conference poster

Johnsen, Geir; Volent, Zsolt; Sigernes, F.; Berge, Jørgen; Hovland, Erlend Kjeldsberg; Sakshaug, Egil. (2007) Local hyperspectral imaging of ocean colour from tethered balloons in the Arctic. Arctic Frontiers Conference
Conference poster

Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir. (2007) Temperature effects on photosynthesis-light responses measured by O2 evolution, pulse amplified modulated (PAM) fluorescence and 14C assimilation. AquaFluo Conference
Conference poster

Johnsen, Geir; Volent, Zsolt; Sigernes, Fred; Berge, Jørgen; Hovland, Erlend Kjeldsberg; Sakshaug, Egil. (2007) Local hyperspectral imaging of ocean colour from tethered balloons in the Arctic. Arctic Frontiers

2006

Conference lecture

Johnsen, Geir. (2006) Marine Biology ?. IBI meeting, NTNU
Conference lecture

Johnsen, Geir. (2006) Nye tider for foto-opto-molekylo (FOM) biologi. IBI meeting, NTNU
Conference lecture

Johnsen, Geir. (2006) Monitoring of phytoplankton on coastal areas. UNESCO SCOR Meeting
Contribution to radio or TV

Johnsen, Geir. (2006) Medisin fra havet.
Conference poster

Hancke, Torunn Beate; Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2006) The use of PAM fluorescence and bio-optical characteristics to estimate oxygen production in phytoplankton. Annual meeting at the Association of Norwegian Oceanographers
Conference lecture

Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir; Glud, Ronnie N. (2006) Temperature effects on photosynthesis: Measurements using O2-microelectrodes, Pulse Amplitude Modulated (PAM) fluorescence and 14C-incorporation techniques. Annual meeting at the Association of Norwegian Oceanographers

2005

Conference lecture

Edvardsen, Bente; Eikrem, Wenche; Shalchian-Tabrizi, Kamran; Riisberg, Ingvild; Johnsen, Geir; Naustvoll, Lars; Throndsen, Jahn. (2005) Phylogeny of a new ichthyotoxic dictyochophyte forming blooms in the North Sea. Seminarserie ved CNRS Station Biologique de Roscoff
Lecture

Johnsen, Geir. (2005) Introduction & overview of Marine Ecosystems to NFR. “Kunnskapsstatus om marine økosystem I Norge 2005”. Meeting in “Havet og kysten”
Conference lecture

Johnsen, Geir. (2005) Kunnskapsstatus om marine økosystem I Norge 2005. Meeting in “Havet og kysten”
Conference lecture

Johnsen, Geir. (2005) "Forskning og foto under vann” Fotoptip of GJ.www.nrk.no/programmer/TV/Newton´s hjemmside Publ. 1409 and updated 210905. Newton spesial (NRK news website)
Conference lecture

Johnsen, Geir. (2005) "Forskning og foto under vann” Fotoptip of GJ.www.nrk.no/programmer/TV/Newton´s hjemmside Publ. 1409 and updated 210905. Newton spesial (NRK news website)
Conference lecture

Johnsen, Geir. (2005) Evidence of global warming became so overwhelming in 2004, now the question is: What can we do about it. Vol 26, No 1 (see MEPS 303). Discover magazine (Jan issue by R. Kunzig).
Contribution to radio or TV

Johnsen, Geir; Zotchev, Sergey; Moore, Thomas. (2005) The medical gold rush. Sky News (England). 7 min program of NTNU´s bioprospecteering NFR project “Marine actinopmycetes”. Kew words with NTNU´s ROV to harvest songes to isolate new type of antiobiotica from sponges in the Trondheimsfjord.
Conference poster

Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir. (2005) Temperature effects on photosynthesis-light responses measured by O2-evolution, 14C-assimilation and Pulse Amplitude Modulated (PAM) fluorescence. Am. Soc. Limnol. Oceanogr. (ASLO) conference
Contribution to radio or TV

Johnsen, Geir. (2005) Er det mulig å se alger fra satelitt?.
Contribution to radio or TV

Johnsen, Geir; Bordvik, Hans Otto. (2005) Forskning og foto under vann. (GJ underwater video and comments). Newton.

2004

Conference lecture

Edvardsen, Bente; Eikrem, Wenche; Johnsen, Geir; Shalchian-Tabrizi, Kamran; Riisberg, Ingvild; Naustvoll, Lars; Throndsen, Jahn. (2004) Phylogeny of a new ichthyotoxic dictyochophyte forming blooms in the Skagerrak. 11th International Conference on Harmful Algae
Conference poster

Volent, Z.; Johnsen, Geir; Sigernes, F.. (2004) Comparison study between airborne remote sensing of of ocean colour using hyperspectral imager and in situ measurements of optical properties in surface waters in an Arctic fjord, Svalbard, May 2004. Poster
Conference lecture

Johnsen, Geir; Hancke, Torunn Beate. (2004) SISCAL dissemination evaluation. Foredrag
Conference poster

Salvesen, Ingrid; Brakstad, I.; Givskov, M.; Johnsen, Geir; Skindersø, M.; Størseth, Trond. (2004) Antibacterial activity in crude extracts of marine macroalgae. Poster
Conference poster

Berge, J.; Johnsen, Geir; Nilsen, F.; Gulliksen, B.. (2004) Discovery of blue mussels (Mytilus edulis) in Svalbard - indication of temperature increase in the Arctic marine environment. Poster
Conference lecture

Johnsen, Geir; Evertsen, Jussi. (2004) Photosynthetic Nudibranchs and Sacoglossans. Foredrag/poster
Conference lecture

Johnsen, Geir; Hancke, Torunn Beate. (2004) SISCAL processor evaluation. Fordrag
Conference lecture

Johnsen, Geir. (2004) Presentation of SISCAL and the use of remote sensing. Foredrag
Conference lecture

Johnsen, Geir; Evertsen, Jussi. (2004) Photosynthetic Opisthobranchs. Foredrag
Conference lecture

Forbord, Silje; Johnsen, Geir. (2004) Marine bio-prospecteering of marine macroalgae. Foredrag
Conference lecture

Johnsen, Geir. (2004) Light utilzation in 13 different pigments groups of phytoplankton. Foredrag
Conference lecture

Edvardsen, Bente; Eikrem, Wenche; Johnsen, Geir; Naustvoll, L.; Riisberg, I.; Shalchian-Tabrizi, K.; Trondsen, Jahn. (2004) Verruca fascima gen. et. sp. nov. (Dictyochophyceae, Heterokontophyta) a bloom forming ichthyotoxic flagellate isolated from Skagerrak, Norway. Foredrag
Conference poster

Bredholt, Harald; Fjærvik, E.; Johnsen, Geir; Johansen, G.; Sletta, Håvard; Ellingsen, Trond Erling; Zotchev, Sergey. (2004) Isolation and characterization of actinomycete bacteria from sediments in the Trondheimsfjord, Norway. Genetics and Molecular Biology of Industrial Microorganisms conference
Conference poster

Bredholt, Harald; Fjærvik, Espen; Johnsen, Geir; Hancke, Torunn Beate. (2004) Isolation and characterization of actinomycete bacteria from sediments in the Trondheimsfjord, Norway. GMBIM/BMP
Conference lecture

Olsen, Lasse Mork; Øzturk, Murat; Sakshaug, Egil; Vadstein, Olav; Sandaa, Ruth Anne; Johnsen, Geir. (2004) Interactions between metabolism, geochemistry and bacterial diversity in cultures of the marine dinoflagellate Prorocentrum minimum. ASLO møte
Conference lecture

Bredholt, Harald; Fjærvik, E.; Hakvåg, Sigrid; Sletta, Håvard; Johnsen, Geir; Ellingsen, Trond Erling; Zotchev, Sergey. (2004) Mining for antibiotic-producing bacteria in the Trondheim fjord. BIOPROS 2004

2003

Conference poster

Forbord, Silje; Valle, Kristin Collier; Hilstad, Kari; Evertsen, Jussi; Johnsen, Geir. (2003) Annual variation of pigments in marine red-, brown- and green macroalgae. Norske havforskeres forening, årsmøtet
Conference poster

Evertsen, Jussi; Johnsen, Geir. (2003) Opisthobranchs with solar panels. Norske havforskeres forening, årsmøtet
Conference poster

Hilstad, Kari; Evertsen, Jussi; Forbord, Silje; Valle, Kristin Collier; Johnsen, Geir. (2003) Annual variation in bio-optical characteristics in marine red-, brown-, and green macro algae. Norske havforskeres forening, årsmøtet
Conference poster

Valle, Kristin Collier; Forbord, Silje; Hilstad, Kari; Evertsen, Jussi; Johnsen, Geir. (2003) Detectation of annual variation in red-, brown- and green macroalgae using in situ video technique and fluorescence microscopy. Norske havforskeres forening, årsmøtet
Conference poster

Volent, Z.; Johnsen, Geir. (2003) Presentation of an optical sensor for in situ detection of phytoplankton, inorganic particles and yellow substance. Norske Havforskers Forenings årsmøte
Conference poster

Johnsen, Geir. (2003) Bio-optical characterization in 10 major phytoplankton classes. Norske Havforskers Forenings årsmøte
Conference lecture

Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL prototype evaluation. SISCAL Second Annual Meeting

2002

Conference poster

Evertsen, Jussi; Johansen, Torunn Beate; Johnsen, Geir. (2002) MODTEQ Module 2 - bio-optical methods. Model based development of advanced marine equipment. Norske Havforskeres Forenings årsmøte
Conference poster

Salvesen, Ingrid; Størseth, Trond; Johnsen, Geir; Brakstad, O.G.. (2002) Bakteriehemmenede forbindelser i marine alger: Utvikling av miljøvennlige strategier for å kontrollere virulens og begroing. Ikke opplyst
Conference poster

Fell, Frank; Herut, Barak; Johansen, Torunn Beate; Johnsen, Geir; Brozek, Morten; Hanssen, Frank. (2002) SISCAL: internet-based delivery of near-real-time data products on coastal areas and lakes from satellite imagery. SPIE
Conference poster

Størseth, Trond; Reitan, Kjell Inge; Salvesen, Ingrid; Skjermo, Jorunn; Rainuzzo, J.; Johnsen, Geir; Partali, Vassilia. (2002) Immunostimulants and Antimicrobial Compounds from algae, Isolation and Characterization. Marin bioprospektering
Conference poster

Salvesen, Ingrid; Johnsen, Geir; Rainuzzo, J.; Reitan, Kjell Inge; Skjermo, Jorunn; Størseth, Trond. (2002) Immunstimulerende og antibakterielle forbindelser fra marine alger. Marin bioprospektering. Marin bioprospektering
Conference poster

Johansen, Torunn Beate; Evertsen, Jussi; Johnsen, Geir. (2002) SISCAL - satellite-based information system on coastal areas and lakes. Norske havforskeres forening, årsmøtet
Conference lecture

Fell, Frank; Herut, Barak; Johansen, Torunn Beate; Johnsen, Geir; Brozek, Morten; Hanssen, Frank. (2002) SISCAL project: establishing an internet-based delivery of near-real-time data products on coastal areas and lakes from satellite imagery. SPIE 2002
Conference lecture

Børsheim, Knut Yngve; Kirkvold, Ståle; Johansen, Torunn Beate; Johnsen, Geir. (2002) Measurement of phytoplankton mortality as a tool to estimate turnover of phytoplankton biomass. Phytoplankton Productivity. An Appreciation of 50 years of the study of oceans and lakes
Conference lecture

Johnsen, Geir. (2002) End user requirements in SISCAL (EU Romete sensing project). SISCAL meeting
Lecture

Johnsen, Geir. (2002) Queen Maud and myself. Norwegian Antarctic Research Expedition jan-mar 2001. Primary production under the sea ice

2001

Contribution to radio or TV

Johnsen, Geir; Johansen, Torunn Beate. (2001) Norsk Antarktis Forsknings Ekspedisjon "Fotosyntese i måneskinn".
Conference lecture

Ødegaard, Øyvind Tangen; Sortland, Bjørn; Ellingsen, Ingrid Helene; Slagstad, Dag; Johnsen, Geir; Sakshaug, Egil. (2001) An Interdisciplinary Marine Research Programme: How to promote generative interaction between marine scientists, modellers and engineers. OCEANS, 2001. MTS/IEEE Conference and Exhibition

2000

Conference lecture

Johnsen, Geir. (2000) Bio-optics as a tool to detect physiological status in toxic algae. Conference in EC MAST III prosject.
Conference lecture

Johnsen, Geir; Legrand, C; Chauton, Matilde Skogen; Eigeland, E; Sakshaug, Egil. (2000) The use of a DIVING-PAM for detection of irradiance, biomass and photosystem II fluorescene yield in harmful algal bloom experiments: Discussion of methodological aspects. HAB 2000
Conference lecture

Legrand, C; Johnsen, Geir; Graneli, E; Sakshaug, Egil. (2000) Effect of polyamines on growth and toxicity of Chrysochromulina leadbeateri and Prymnesium patellifreum (Haptophytes). HAB 2000
Conference lecture

Legrand, C; Johnsen, Geir; Graneli, E; Sakshaug, Egil. (2000) Effect of polyamines on growth and toxicity of Chrysochromulina leadbeateri, Haptophytae. Proceedings of the 9th International conference on Harmful Algal Blooms.
Conference lecture

Johnsen, Geir. (2000) Bio-optical instruments for use in marine water and plankton. SINTEF seminarseries in bio-optics held at auditorium E5-101 Realfagsbygget NTNU, Gløshaugen.
Conference lecture

Johnsen, Geir. (2000) Why bio-optics in marine biology. 2nd NTNU seminarseries in bio-optic held at the auditorium Trondhjem Biological Station.
Lecture

Mork, Jarle; Johnsen, Geir; Tokle, Nils Egil; Evensen, Jussi; Andresen, Kjersti. (2000) Trondhjem Biologiske Stasjon. Poster presentasjon. Trøndelagsmessa 2000
Conference poster

Legrand, C; Johnsen, Geir; Graneli, E; Sakshaug, Egil. (2000) Effect of polyamines on growth and toxicity of Chrysochromulina leadbeateri and Prymnesium patelliferum (Haptophytae). 9th International conference on Harful Algal Blooms.
Conference lecture

Chauton, Matilde Skogen; Johnsen, Geir; Legrand, C; Sakshaug, Egil; Granëli, E. (2000) Development of a pontential harmful algal bloom in a mesocosm experiment monitored through pigment analysis and bio-optical measurements. HAB 2000
Conference lecture

Granëli, E; Legrand, C; Carlsson, P; Maestrini, SY; Johnsen, Geir; Hummert, C; Pallon, J; Luckas, B; Sakshaug, Egil. (2000) Nitrogen and phosphorus deficiency favours the dominance and toxin content of harmful species in summer Baltic Sea phytoplankton. HAB 2000
Conference poster

Graneli, E; Legrand, C; Carlsson, P; Maestrini, S.Y; Hummert, C; Reichelt, M; Johnsen, Geir; Pallon, J; Luckas, B; Sakshaug, Egil. (2000) Nitrogen and phosphorus deficiency favours the dominance and toxin content of harmful species in summer Baltic Sea phytoplankton. 9th International conference on Harmful Algal Blooms.
Conference poster

Johnsen, Geir; Legrand, C; Graneli, C; Sakshaug, Egil. (2000) The use of a DIVING-PAM for detection of irradiance, biomass and photosystem II fluorescence yields in harmful algal bloom experiments: Discussion of methodological aspects. 9th International conference on Harmful Algal Blooms.
Conference poster

Tilstone, G; Johnsen, Geir; Chauton, Matilde Skogen; Johansen, T; Figueiras, F.G. (2000) Temporal evolution of photosynthetic parameters and primary prodution during a bloom of an ichthytoxic prymnesiophyte under different N/P ratios. 9th International conference on Harmful Algal Blooms.
Conference poster

Chauton, Matilde Skogen; Johnsen, Geir; Legrand, C; Graneli, E; Sakshaug, Egil. (2000) Development of a potential harmful algal bloom in mesocosm experiment monitored through pigment analysis and bio-optical measurements. 9th International conference on Harmful Algal Blooms.
Conference lecture

Wägele, H; Johnsen, Geir. (2000) New result on histology and photosynthetic performance of solar-powered¨ opisthobranchs (Mollusca, Gastropoda, Opisthobranchia) constaining symbiotic chloroplasts or zooxanthellae. -
Conference lecture

Johnsen, Geir. (2000) Inhibition of toxin production in cultures. Conference in EC MART III prosject.
Conference lecture

Johnsen, Geir. (2000) Fish killing species. Conference in EC MAST III project ¨NUTOX¨
Conference lecture

Johnsen, Geir. (2000) PSP producer Alexandrium tamarense II. Conferrnce in EC MAST III project.
Conference lecture

Johnsen, Geir. (2000) Inhibition of toxin production in natural communities. Conference in EC MAST III ¨NUTOX¨

1999

Conference lecture

Legrand, C; Johnsen, Geir; Hummert, C; Graneli, E. (1999) Variation in toxin production in two strains of Alexandrium tamarense: Effects of nitrogen and phosphorus replete vs. limited growth conditions. ASLO winter meeting.
Conference lecture

Graneli, E; Carlsson, P; Legrand, C; Johnsen, Geir; Luckas, B; Maestrini, S. Y; Reichelt, M. (1999) Structuration of marine phytoplankton communities subjected to different levels of N, P and Si limitation in a mesocosm experiment. ASLO winter meeting.

1998

Conference lecture

Chauton, Matilde Skogen; Johnsen, Geir; Sakshaug, Egil. (1998) In vivo fluorescence exitation spectra of phytoplankton. CANIGO 2nd general meeting.
Conference lecture

Johnsen, Geir; Sakshaug, Egil. (1998) Monitoring of Harmful Algal Blooms using bio-optical methods. International Symposium and workshop on harmful algal blooms in the Benguela current region and other upwelling ecosystems. Phagotrophy and toxicity in photosynthetic Prymnesium patellifreum (Haptophyte).

1997

Conference lecture

Johnsen, Geir; Sakshaug, Egil. (1997) Chlorophyll c3-containing prymnesiophytes and dinoglagellates: a potentially harmful phytoplankton group. VIII International Conference on Harmful Algae,

1996

Conference lecture

Egeland, E. S; Johnsen, Geir; Jensen, S Liaaen-. (1996) Variable carotenoid composition in a prasinophycean phytoplankton acclimated to three different irradiances. 11th International Symposium on carotenoids,

1994

Conference lecture

Johnsen, Geir; Sakshaug, Egil. (1994) Pigment composition and photoadaptive pigment variation in three toxic marine dinoflagellate species. Ocean Science Meeting (ASGU/ASLO).

1993

Conference lecture

Johnsen, Geir; Nelson, N. B; Jovine, R. V. M; Prezelin, B. B. (1993) Chromoprotein- and pigment dependent modeling of spectral light absorption in two dinoflagellates, Prorocentrum minimum and Heterocapsa pygmaea. Optical properties and quantum yields of aquatic photosynthetic systems. Binational Scientific Fundation Workshop.

1992

Conference lecture

Volent, Z; Johnsen, Geir. (1992) Presentation of an optical algae sensor "Optisens" designed for Eulerian measurements from a moored buoy. In: Autonomous bio-optical ocean observin systems scientific symposium (ABOOS). [Mangler data]
Conference lecture

Johnsen, Geir; Samset, O; Volent, Z. (1992) Optical characteristics of phytoplankton in relation to remote sensing. In: Autonomous boi-optical ocean observing systems scientific symposium (AB. [Mangler data]

1990

Conference lecture

Johnsen, Geir; Gilstad, M; Sakshaug, Egil. (1990) Diurnal variations in light absorption spectra, fluorescence excitation spectra and pigment composition in the marine diatom skeletonema costatum. NATO/ASI Individual cell & particle analysis in oceanography. Aquafredda di Maratea,
Conference lecture

Gilstad, M; Johnsen, Geir; Sakshaug, Egil. (1990) Diurnal varations in cell chemistry, photosynthetic parameters and respiration in the marine diatom skeletonema costatum. In: NATO/ASI Individual cell & particle analysis in oceanography. Aquafredda di Maratea.

Språkvelger

Geir Johnsen

Geir Johnsen

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