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

2023

Bakken, Sivert; Henriksen, Marie Bøe; Birkeland, Roger; Langer, Dennis David; Oudijk, Adriënne Esmeralda; Berg, Simen. (2023) HYPSO-1 CubeSat: First Images and In-Orbit Characterization. Remote Sensing
Academic article
Williamson, David Roddan; Moreira Fragoso, Glaucia; Majaneva, Sanna Kristiina; Dallolio, Alberto; Halvorsen, Daniel Ørnes; Hasler, Oliver Kevin. (2023) Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography
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
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
Schartmuller, Bernhard; Anderson, Philip; Mckee, David; Connan-McGinty, Stacey; Kopec, Tomasz Piotr; Daase, Malin Hildegard Elisabeth. (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
Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa. (2023) Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene
Academic literature review

2022

Nøland, Annecken; Johnsen, Geir; Aberle-Malzahn, Nicole. (2022) Autonomous Underwater Vehicle (AUV) based study of zooplankton communities, using a silhouette camera and artificial intelligence. NTNU
Masters 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. NTNU
Masters 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/article/Conference paper
Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Fragoso, Glaucia Moreira; 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
Fragoso, Glaucia Moreira; Davies, Emlyn John; Fossum, Trygve Olav; Ullgren, Jenny; Majaneva, Sanna; Aberle-Malzahn, Nicole. (2022) Contrasting phytoplankton-zooplankton distributions observed through autonomous platforms, in-situ optical sensors and discrete sampling. PLOS ONE
Academic article
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
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 Norges teknisk-naturvitenskapelige universitet
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters thesis
Bjerkvoll, Mikkel; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Aerial and underwater hyperspectral imagery for shallow benthic nature type mapping. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters thesis
Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir. (2022) Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems
Academic article
Oudijk, Esmée; Hasler, Oliver Kevin; Øveraas, Henning; Marty, Sabine; Williamson, David Roddan; Svendsen, Torbjørn Karl. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
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

2021

Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura. (2021) Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biology
Academic article
Cardwell, CR; Berge, Jørgen; Johnsen, Geir. (2021) Arctic voyage shines light on some cold, hard truths. The Herald, UK
Popular scientific article
Bazilchuk, Nancy Reney; Berge, Jørgen; Johnsen, Geir. (2021) Lysforurensning I Arktis kan ha ødelagt forskningsresultater. Gemini.no
Popular scientific article
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2019) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
Other product
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2018) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer. .
Other product
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2019) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
Other product
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2020) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
Other product
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2017).
Other product
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2018) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
Other product
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2020) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
Other product
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2019) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
Other product
Ringvold, Halldis; Taite, Morag; Allcock, A. Louise; Vecchione, Michael; Péan, Michel; Sandulli, Roberto. (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
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
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 scientific article
Bazilchuk, Nancy Reney; Stahl, Annette; Johnsen, Geir; Saad, Aya; Thu, Maren; Nøland, Annecken. (2021) Sporhunden som lukter mikroalger. . Gemini.no
Popular scientific 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. Doktoravhandlinger ved NTNU (2021-254)
Doctoral dissertation
Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2021) Underwater hyperspectral imaging as a tool for benthic habitat mapping. Doktoravhandlinger ved NTNU (2021/271)
Doctoral dissertation
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
Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan H.; Mckee, David. (2021) All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic. Applied Optics
Academic article
Geoffroy, Maxime; Langbehn, Tom Jasper; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault. (2021) Pelagic organisms avoid white, blue, and red artificial light from scientific instruments. Scientific Reports
Academic article
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2019).
Other product
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
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2018).
Other product
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2020).
Other product
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2017) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) .
Other product
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Photosynthetic active radiation (PAR) time series measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
Other product
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2017) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
Other product
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2020) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
Other product
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2018) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
Other product
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2017) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
Other product
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

2020

Ramirez-Llodra, Eva; Hilário, Ana; Paulsen, Emil; Costa, Carolina; Bakken, Torkild; Johnsen, Geir. (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
Berge, Jørgen; Johnsen, Geir. (2020) Life and Light at the Dead of Night. Springer
Academic chapter/article/Conference paper
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr. (2020) Light in the Polar Night. Springer
Academic chapter/article/Conference paper
Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H.. (2020) Operative Habitat Mapping and Monitoring in the Polar Night. Springer
Academic chapter/article/Conference paper
Berge, Jørgen; Johnsen, Geir. (2020) • Polar Night Exhibitions in Russia 2020. Kaliningrad – World Ocean Museum.
Museum exhibition
Gibbens, Sarah; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2020) As the Arctic warms, light pollution may pose a new treat to marine life. . National Geographic
Interview Journal
Johnsen, Geir; Leu, Eva; Gradinger, Rolf. (2020) Marine Micro- and Macroalgae in the Polar Night. Springer
Academic chapter/article/Conference paper
Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.. (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) Polar night marine ecology - life and light in the dead of night. Springer Advances in Polar Ecology (0)
Academic anthology/Conference proceedings
Berge, Jørgen; Johnsen, Geir. (2020) Polar Night exhibition in Karelia (Petrozavodsk, Russia): 03.03 – 03.04.2020 . Polar Night exhibition, Karelia (Petrozavodsk, Russia). March-April 2020
Museum exhibition
Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole. (2020) Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer. Oceanography
Academic article
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Introduction. Springer
Introduction
Fragoso, Glaucia Moreira; 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
Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan. (2020) Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots. Remote Sensing
Academic article

2019

Fragoso, Glaucia Moreira; Davies, Emlyn John; Ellingsen, Ingrid H.; Chauton, Matilde Skogen; Fossum, Trygve Olav; Ludvigsen, Martin. (2019) Physical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspot. Progress in Oceanography
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
Graham, Lisa Kristine Hernandez; Johnsen, Geir; Christensen-Dalsgaard, Signe. (2019) A pilot study assessing drones for mapping and monitoring of European shags. Institutt for biologi, NTNU
Masters thesis
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
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
Pavlov, Alexey K.; Leu, Eva; Hanelt, Dieter; Bartsch, Inka; Karsten, Ulf; Hudson, Stephen. (2019) The Underwater Light Climate in Kongsfjorden and Its Ecological Implications. Springer
Academic chapter/article/Conference paper
Bazilchuk, Nancy Reney; Fossum, Trygve Olav; Fragoso, Glaucia Moreira; 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 scientific article
Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Davies, Emlyn John; Ullgren, Jenny; Mendes, Renato; Johnsen, Geir. (2019) Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Science robotics
Academic article
Fragoso, Glaucia Moreira; 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

Fragoso, Glaucia Moreira; 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
Dumke, Ines; Nornes, Stein Melvær; Purser, Autun; Marcon, Yann; Ludvigsen, Martin; Ellefmo, Steinar Løve. (2018) First hyperspectral imaging survey of the deep seafloor: High-resolution mapping of manganese nodules. Remote Sensing of Environment
Academic article
Zolich, Artur Piotr; De La Torre, Pedro R.; Rodwell, Shane; Geoffroy, Maxime; Johnsen, Geir; Berge, Jørgen. (2018) An ice-tethered buoy for fish and plankton research. IEEE conference proceedings
Academic chapter/article/Conference paper
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 Norges teknisk-naturvitenskapelige universitet
Masters thesis
Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin; Hansen, Roy Edgar; Maarleveld, Thijs. (2018) Towards Autonomous Operations and Systems in Marine Archaeology. Doktoravhandlinger ved NTNU (IMT-12)
Doctoral dissertation
Strømsholm, Jørgen; Johnsen, Geir; Ludvigsen, Martin. (2018) Eyes beneath the surface - using a miniROV to reveal habitat and dietary choices of the European shag. NTNU MSc thesis
Masters thesis
Kauko, Hanna Maria; Johnsen, Geir; Assmy, Phillipp. (2018) Light response and acclimation of macroalgae in a changing Arctic. Doktoravhandlinger ved NTNU (2018)
Doctoral dissertation
Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning - enda en kilde til bekymring. Svalbardposten
Feature article
Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning truer livet i Arktis. Aftenposten Viten
Feature article
Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; De La Torre, Pedro R.; Nornes, Stein Melvær. (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
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. Doktoravhandlinger ved NTNU (2018:202)
Doctoral dissertation
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
Fossum, Trygve Olav; Eidsvik, Jo; Ellingsen, Ingrid H.; Alver, Morten; Fragoso, Glaucia Moreira; Johnsen, Geir. (2018) Information-driven robotic sampling in the coastal ocean. Journal of Field Robotics (JFR)
Academic article
Kauko, Hanna Maria; Olsen, Lasse Mork; Duarte, Pedro; Peeken, Ilka; Granskog, Mats A.; Johnsen, Geir. (2018) Algal colonization of young arctic sea ice in spring. Frontiers in Marine Science
Academic article
Dumke, Ines; Purser, Autun; Marcon, Yann; Nornes, Stein Melvær; Johnsen, Geir; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports
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
Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert. (2018) Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic. Polar Biology
Short communication
Johnsen, Geir; Norli, Marit; Moline, Mark A.; Robbins, Ian; Quillfeldt, Cecilie von; Sørensen, Kai. (2018) The advective origin of an under-ice spring bloom in the Arctic Ocean using multiple observational platforms. Polar Biology
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
Gabrielsen, Tove M.; Johnsen, Geir. (2018) Skogen på Svalbard. Svalbardposten
Popular scientific article

2017

Berge, Jørgen; Johnsen, Geir; Tandberg, Anne helene. (2017) Polar night - Life and light in the dead of night. Russian Science Week - Lomonosov Moscow State University
Museum exhibition
Otterlei, Inger; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin; Hareide, Nils Roar; Christensen-Dalsgaard, Signe. (2017) 300 000 sjøfugl er forsvunnet fra Runde. Sunnmørsposten
Interview Journal
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. NTNU Trondheim
Masters thesis
Johnsen, Geir; Christiansen, Hanne H; Ravolainen, Virve; Reymert, Per Kyrre; Jenssen, Eva Therese; Arlov, Thor Bjørn. (2017) Utfordrende natur og sikkerhet på Svalbard. Svalbardposten
Feature article
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. NTNU, Trondheim
Masters 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. NTNU, Trondheim
Masters 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. Master science NTNU
Masters 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
Kauko, Hanna Maria; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C.J.; Duarte, Pedro. (2017) Windows in Arctic sea ice: light transmission and ice algae in a refrozen lead. Journal of Geophysical Research (JGR): Biogeosciences
Academic article
Berge, Jørgen; Johnsen, Geir. (2017) Kunnskapshull om livet i Arktis i mørketiden. Aftenposten Viten
Feature article
Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John. (2017) Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic. Scientific Reports
Academic 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; Johnsen, Geir. (2017) Om bambus, spøkelseskreps og et Arktis i endring. Svalbardposten
Feature article
Berge, Jørgen; Johnsen, Geir. (2017) Superkommunisten. Svalbardposten
Feature article
Andersson, Ingvild Henriette Kristin; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin. (2017) Bio-optical diversity on cold water coral habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters thesis

2016

Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) Opp fra polarnattens mørke. Aftenposten Viten
Feature article
Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) A bitter-sweet symphony. Svalbardposten
Feature article
Gätzschmann, Per; Hårsaker, Karstein; Johnsen, Geir; Leite, Stein Roar; Pedersen, Solbjørg; Sørumgård, Marit. (2016) Nye oppdagelser i polarnatta - video. Polarnatt
Museum exhibition
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
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; Johnsen, Geir; Ludvigsen, Martin; Cohen, Jonathan. (2016) Design for latskap - men med store muligheter. Svalbardposten
Feature 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. NTNU
Masters thesis
Bondø, Tor-Hartvig; Johnsen, Geir; Berge, Jørgen. (2016) Fant yrende liv i polarnatta. VG : Verdens gang
Popular scientific article
Berge, Jørgen; Johnsen, Geir. (2016) Mørkets fyrster med påskrudd lys. Svalbardposten
Popular scientific article
Bazilchuk, Nancy Reney; Leite, Stein Roar; Johnsen, Geir; Kjeken, John; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2016) Bomber og buss på havbunnen. Gemini
Popular scientific 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 scientific 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 scientific article
Bjørgan, Espen Halvorsen; Johnsen, Geir; Kjeken, Jon; Ludvigsen, Martin. (2016) Fant buss på 600 m dybde. Adresseavisen
Popular scientific 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
Masters thesis
Liefmann, Stephanie; Johnsen, Geir; Järnegren, Johanna. (2016) Eco-physiological responses of cold-water corals to anthropogenic sedimentation and particle shape. NTNU Mastergrad
Masters thesis
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. Polarnattsutstilling ved Vitenskapsmuseet NTNU
Museum exhibition
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
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Kinderegg i polarnatten. Svalbardposten
Feature 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 scientific article
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Dark lords, werewolves and Indiana Jones in the polar night. Gemini (English edition)
Interview Journal
Krüger, Frida Jørstad; Johnsen, Geir; Kjeken, John; Ludvigsen, Martin. (2016) Gammel buss ble korallrev. NRK Viten
Popular scientific 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 scientific article
Haugstad, Tormod; Erdal, Ivar; Johnsen, Geir. (2016) Kameraet deres «kan bli det nye ekkoloddet». Nå er det norske selskapet i ferd med å lykkes. Teknisk Ukeblad
Interview Journal
Johnsen, Geir. (2016) Yrende liv i Isfjorden. Svalbardposten
Popular scientific article
Aarskog, Karine Nigar; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2016) Et stort løft for arktisk forskning (NTNU & UiT). Universitetet i Tromsø
Article in business/trade/industry journal
Berge, Jørgen; Falk-Petersen, Stig; Renaud, Paul E.; Daase, Malin; Geoffroy, Maxime; Johnsen, Geir. (2016) En reise mot Ultima Thule. Svalbardposten
Popular scientific article
Lervik, Frank; Johnsen, Geir; Ludvigsen, Martin; Kjeken, John. (2016) Det ligger flere busser der. Adresseavisen
Popular scientific article
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Mark spiser opp vrak på havbunnen. Fiskaren
Popular scientific article
Kintisch, Eli; Berge, Jørgen; Last, Kim; Cohen, Jonathan; Johnsen, Geir. (2016) Voyage into darkness . Science
Interview Journal
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Ludvigsen, Martin; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Mørkets fyrster, varulver og Indiana Jones. Gemini
Popular scientific article
Berge, Jørgen; Renaud, Paul E.; Johnsen, Geir; Darnis, Gerald; Geoffroy, Maxime; Daase, Malin. (2016) I grenselandet (mellom Tull og Thule). Svalbardposten
Popular scientific article
Førde, Henny; Forbord, Silje; Handå, Aleksander; Fossberg, Julia; Arff, Johanne; Johnsen, Geir. (2016) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. Journal of Applied Phycology
Academic article

2015

Nilssen, Ingunn; Dos Santos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo M.; Eide, Ingvar. (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
Nilssen, Ingunn; Santos dos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral Montenegro, Marcelo; Eide, Ingvar. (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
Rodriguez, Francisco; Garrido, J.L.; Sabrino, C; Johnsen, Geir; Riobo, P; Franco, J. (2015) Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae). Environmental Microbiology
Academic article
Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) Life and light in the dead of night. Museumsutstilling
Museum 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
Aarekol, Lena; Johnsen, Geir; Berge, Jørgen. (2015) Polarnatt. Liv og lys i mulm og mørke Polarnighth. Life and death in dead of night. Utstilling
Museum exhibition
Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur. (2015) Underwater vehicles for environmental management in coastal areas. IEEE conference proceedings
Academic chapter/article/Conference paper
Tandberg, Anne Helene S.; Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) POLARNATT - liv og lyst i mulm og mørke. Polarnatt - liv og lyst i mulm og mørke
Museum exhibition
Berge, Jørgen; Johnsen, Geir. (2015) Polarnatt - Liv og lys i mulm og mørke Polar night - life and light in the dead of night. Utstilling på Polarmuseet i Tromsø
Museum exhibition
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig. (2015) Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?. PLOS ONE
Academic article
Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.. (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. (2015) Unexpected levels of biological activity during the polar night offer new perspectives on a warming Arctic. Current Biology
Academic article

2014

Pettersen, Ragnhild; Johnsen, Geir; Bruheim, Per; Andreassen, Trygve. (2014) Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms. Organisms Diversity & Evolution
Academic article
Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti. (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
Lund, Lene; Johnsen, Geir; Bakken, Torkild; Gabrielsen, Tove. (2014) Morphological diversity in Laminaria digitata - different species or different phenotypes?. Norwegian University of Science and Technology, Department of Biology
Masters thesis
Valle, Kristin Collier; Johnsen, Geir; Bones, Atle M. (2014) Photoacclimation mechanisms and light responses in marine micro- and macroalgae. NTNU
Doctoral dissertation
Hallerud, Charlotte; Johnsen, Geir; Aamot, Inga. (2014) Pigment composition of macroalgae from a Norwegian kelp forest. NTNU
Masters thesis
Kjerstad, Ingrid; Johnsen, Geir; Sørensen, Asgeir Johan; Bakken, Torkild. (2014) Underwater Imaging and the effect of Inherent Optical Properties on image quality. NTNU
Masters thesis
Førde, Henny; Reitan, Kjell Inge; Johnsen, Geir. (2014) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. NTNU
Masters thesis
Hatlebakk, Maja; Johnsen, Geir; Søreide, Janne. (2014) Effect of lipids and fatty acid composition on success of reproduction in Calanus glacialis. NTNU
Masters thesis
Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik. (2014) Managing data from multiple sensors in an interdisciplinary research cruise. Amsterdam University Press
Academic chapter/article/Conference paper
Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2014) Elemental composition in various marine brown, green and red macro algae with respect to season and tissue age. NTNU
Masters thesis
Kvernvik, Ane Cecilie; Johnsen, Geir; Aamot, Inga. (2014) How lamina age influence photosynthetic response to light variations in Saccharina latissima. NTNU
Masters thesis
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
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
Hansen, Ingrid; Pettersen, Ragnhild; Beuchel, Frank; Cochrane, Sabine; Frantzen, marianne; Ekehaug, Stefan. (2014) Underwater hyperspectral imaging (UHI) for environmental mapping and monitoring of seabed habitats. Ocean Optics
Abstract
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
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
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
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
Abstract
Nilssen, Ingunn; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen; Nornes, Stein Melvær. (2014) Integrated environmental monitoring; a methodological approach to optimise knowledge gathering and sampling strategy. Ocean Optics
Abstract
Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Valle, Kristin Collier. (2014) Photoacclimation mechanisms and light responses in marine micro- and macroalgae. Doktoravhandlinger ved NTNU (74)
Doctoral dissertation
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
Errata
Berge, Jørgen; Cottier, Finlo; Varpe, Øystein; Renaud, Paul; Falk-Petersen, Stig; Kwasniewski, Sawomir. (2014) Arctic complexity: A case study on diel vertical migration of zooplankton. Journal of Plankton Research
Academic article
Eldevik, Tor; Reigstad, Marit; Falck, Eva; Gerland, Sebastian; Jentoft, Sissel; Johnsen, Geir. (2014) Arven efter Nansen. Forskningsplan for det sentrale og nordlige Barentshavet. UiT Norges arktiske universitet UiT Norges arktiske universitet
Report
Hancke, Kasper; Hovland, Erlend Kjeldsberg; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark A.. (2014) Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance. Journal of Marine Systems
Academic article
Hovland, Erlend Kjeldsberg; Hancke, Kasper; Alver, Morten; Drinkwater, Kennneth F.; Høkedal, Jo; Johnsen, Geir. (2014) Optical impact of an Emiliania huxleyi bloom in the frontal region of the Barents Sea. Journal of Marine Systems
Academic article

2013

Ingrid, Hansen; Johnsen, Geir; Sørensen, Asgeir Johan. (2013) Optical Mapping of Cold-water Corals in Trondheimsfjorden and Svalbard. NTNU
Masters 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. MSc Thesis (2013)
Masters 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
Pettersen, Ragnhild; Johnsen, Geir. (2013) Identification of marine organisms using Chemotaxonomy and Hyperspectral imaging. Doktoravhandlinger ved NTNU (292)
Doctoral dissertation
Båtnes, Anna Solvang; Johnsen, Geir. (2013) Light in the dark – the role of irradiance in the high Arctic marine ecosystem during polar night. Doktoravhandlinger ved NTNU (151)
Doctoral dissertation
Johnsen, Geir; Volent, Zsolt; Dierssen, Heidi; Pettersen, Ragnhild; Ardelan, Murat Van; Søreide, Fredrik. (2013) Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties. Woodhead Publishing Limited
Academic chapter/article/Conference paper
Ludvigsen, Martin; Johnsen, Geir; Lågstad, Petter Arthur; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord. IEEE conference proceedings
Academic chapter/article/Conference paper
Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Nymark, Marianne. (2013) Light responses in the marine diatom Phaeodactylum tricornutum. Doktoravhandlinger ved NTNU (378)
Doctoral dissertation
Berge, Jørgen; Johnsen, Geir; Falk-Pettersen, Stig. (2013) Mørkets hemmeligheter. Svalbardposten
Popular scientific article
Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir. (2013) Molecular and photosynthetic responses to prolonged darkness and subsequent acclimation to re-illumination in the diatom Phaeodactylum tricornutum. PLOS ONE
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

2012

Bjørdalsbakke, Lise Kristin; Johnsen, Geir; Bakken, Torkild; Berge, Jørgen. (2012) Population structure, parasitism and prey preference in Sclerocrangon boreas and S. ferox, Svalbard. NTNU
Thesis at a second degree level
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 water. NTNU
Doctoral dissertation
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
Belseth, Elen; Johnsen, Geir; Berge, Jørgen. (2012) Eco-physiology of the Arctic kelp Laminaria solidungula. NTNU Master thesis
Masters 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. NTNU Master theses
Masters thesis
Gabrielsen, Tove M; Quillfeldt, Cecilie von; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden. Svalbardposten
Reader opinion piece
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
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2012) Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2012)
Academic anthology/Conference proceedings

2011

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
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 Norges teknisk-naturvitenskapelige universitet
Masters thesis
Brunet, Christophe; Johnsen, Geir; Lavaud, Johan; Roy, Suzanne. (2011) Pigments and photoacclimation processes. Cambridge University Press
Academic chapter/article/Conference paper
Johnsen, Geir; Bricaud, Annick; Nelson, Norman; Prézelin, Barbara; Bidigare, Robert. (2011) In vivo bio-optical properties of phytoplankton pigments. Cambridge University Press
Academic chapter/article/Conference paper
Volent, Zsolt; Johnsen, Geir; Hovland, Erlend Kjeldsberg; Folkestad, Are; Olsen, Lasse Mork; Tangen, Karl. (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. (2011) Optical monitoring of phytoplankton bloom pigment signatures. Cambridge University Press
Academic chapter/article/Conference paper
Llewellyn, Carole A.; Roy, Suzanne; Johnsen, Geir; Egeland, Einar Skarstad; Chauton, Matilde ; Hallegraeff, Gustaff. (2011) Perspectives on future directions. Cambridge University Press
Academic chapter/article/Conference paper
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Preface. Cambridge University Press
Foreword
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Acknowledgements. Cambridge University Press
Other
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2011)
Academic anthology/Conference proceedings
Jouenne, Fabien; Eikrem, Wenche; Le Gall, F; 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
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

2010

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
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/
Abstract
Johnsen, Geir; Søreide, Fredrik. (2010) Underwater hyperspectral imaging of marine mineral deposits. Underwater Mining meeting Institute (UMI)
Abstract

2009

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

2008

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
Masters thesis
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
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
Bakken, Torkild; Evertsen, Jussi; Johnsen, Geir. (2008) Vitenskapelig dykking - behov for endringer i forskriften. Dykkenytt : informasjonsorgan for dykkeindustrien
Article in business/trade/industry journal
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
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combined use of AUV and hyperspectral imaging to mapping sea-surface and macroalgae. Ocean Optics
Abstract

2007

Kleiven, Mona; Johnsen, Geir. (2007) Pigmentation in Halocynthia pyriformis from Isfjorden, Spitsbergen. NTNU, Institutt for biologi
Masters 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
Masters thesis
Stübner, Eike; Johnsen, Geir. (2007) Biogeographical distribution of temperate vs. Arctic benthic species around Svalbard. NTNU, Institutt for biologi
Masters thesis
Pettersen, Ragnhild; Johnsen, Geir. (2007) Phytoplankton systematics and pigmentation in the Arctic. NTNU, Institutt for biologi
Masters thesis
Hancke, Kasper; Johnsen, Geir. (2007) Photosynthetic responses as a function of light and temperature: Field and laboratory studies on marine microalgae. NTNU, Institutt for biologi
Doctoral dissertation
Johnsen, Geir; Volent, Zsolt; Sigernes, F.. (2007) Fine scale studies using hyper-spectral remote sensing. ESSAS Meeting in Marine Arctic Climate
Report
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
Thesis at a second degree level
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
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
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
Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir; Naustvoll, L. (2007) Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology
Academic article
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 UiT Norges arktiske universitet
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 UiT Norges arktiske universitet
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 UiT Norges arktiske universitet
Report
Johnsen, Geir. (2007) Arctic Life: Bridging ecosystem function using remote sensing technologies. Svalbard Science Forum
Popular scientific 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

2006

Sylling, Guro; Thingstad, Per Gustav; Johnsen, Geir. (2006) Marin bunndyrfauna (Gastropoda, Bivalvia) - Konsekvenser av åpning av veifylling over Ramsarområdet Tautrasvaet. NTNU, Institutt for biologi
Masters thesis
Carlsen, Beth Paludan; Johnsen, Geir. (2006) Makroepifauna associeret med Laminaria digitata og L. saccharina, Svalbard. NTNU, Institutt for biologi
Masters thesis
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Editorial
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
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
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
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
Report
Johnsen, Geir. (2006) Warming Arctic sees return of blue mussels after 1000 years. National Geographic
Popular scientific article
Onstad, L; Evertsen, Jussi; Johnsen, Geir. (2006) Snegle på solceller. Gemini
Popular scientific article

2005

Hilstad, Kari; Johnsen, Geir. (2005) In situ tidsseriemålinger av lyshøstingsegenskaper og cellekjemi hos marine makroalger i Trondheimsfjorden. NTNU, Institutt for biologi
Thesis at a second degree level
Olsen, Lasse Mork; Johnsen, Geir. (2005) Interactions between marine osmo- and phagotrophs in different physicochemical environments. NTNU, Institutt for biologi
Doctoral dissertation
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
Thesis at a second degree level
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 dissertation
Sakshaug, Egil; Johnsen, Geir. (2005) Absorption, fluorescence excitation and photoacclimation in phytoplankton. Multi-Science Publishing
Academic chapter/article/Conference paper
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
Sakshaug, Egil; Johnsen, Geir. (2005) Algal cultures, Analogues of Blooms and Applications. Multi-Science Publishing Multi-Science Publishing
Academic anthology/Conference proceedings
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
Bordvik, Hans Otto; Johnsen, Geir. (2005) “En glupsk nellik”. NEWTON websider (NRK)
Popular scientific article
Indergaard, M; Nordtvedt, M; Johnsen, Geir. (2005) Satellittmålinger for miljøet (SISCAL project, NTNU, IBI). Gemini
Popular scientific article
Bordvik, Hans Otto; Johnsen, Geir. (2005) “Forskning og foto under vann”. NEWTON websider (NRK)
Popular scientific 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
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

2004

Hancke, Torunn Beate; Johnsen, Geir. (2004) SISCAL processor evaluation document. www.siscal.net
Report
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

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
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
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

2002

Johansen, Torunn Beate; Johnsen, Geir. (2002) End User Requirements document. [Mangler utgivernavn]
Report
Johansen, Torunn Beate; Johnsen, Geir. (2002) End User requirement evaluation document. [Mangler utgivernavn]
Report
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
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
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

1992

Syvertsen, E.; Hegseth, E; Johnsen, Geir; Sakshaug, Egil; Gulliksen, B; Lønne, O. J. (1992) Livet i isen (The life in the ice). In Økosystem Barentshavet. [Mangler utgivernavn]
Non-fiction book
Sakshaug, Egil; Kristiansen, S; Syvertsen, E; Eilertsen, H. C; Gilstad, M; Hegseth, E. N. (1992) Planktonalger (Phytoplankton). In Økosystem Barentshavet. [Mangler utgivernavn]
Non-fiction book
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
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; Sakshaug, Egil; Vernet, Maria. (1992) Pigment composition, spectral characteriation and photosynthetic parameters in Chrysochromulina polylepis. Marine Ecology Progress Series
Academic article

1991

Johnsen, Geir. (1991) Proceedings from a scientific working meeting. Fisken og Havet
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
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

Journal publications

Bakken, Sivert; Henriksen, Marie Bøe; Birkeland, Roger; Langer, Dennis David; Oudijk, Adriënne Esmeralda; Berg, Simen. (2023) HYPSO-1 CubeSat: First Images and In-Orbit Characterization. Remote Sensing
Academic article
Williamson, David Roddan; Moreira Fragoso, Glaucia; Majaneva, Sanna Kristiina; Dallolio, Alberto; Halvorsen, Daniel Ørnes; Hasler, Oliver Kevin. (2023) Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography
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
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
Schartmuller, Bernhard; Anderson, Philip; Mckee, David; Connan-McGinty, Stacey; Kopec, Tomasz Piotr; Daase, Malin Hildegard Elisabeth. (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
Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa. (2023) Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene
Academic literature review
Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Fragoso, Glaucia Moreira; 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
Fragoso, Glaucia Moreira; Davies, Emlyn John; Fossum, Trygve Olav; Ullgren, Jenny; Majaneva, Sanna; Aberle-Malzahn, Nicole. (2022) Contrasting phytoplankton-zooplankton distributions observed through autonomous platforms, in-situ optical sensors and discrete sampling. PLOS ONE
Academic article
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
Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir. (2022) Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems
Academic article
Oudijk, Esmée; Hasler, Oliver Kevin; Øveraas, Henning; Marty, Sabine; Williamson, David Roddan; Svendsen, Torbjørn Karl. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
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
Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura. (2021) Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biology
Academic article
Cardwell, CR; Berge, Jørgen; Johnsen, Geir. (2021) Arctic voyage shines light on some cold, hard truths. The Herald, UK
Popular scientific article
Bazilchuk, Nancy Reney; Berge, Jørgen; Johnsen, Geir. (2021) Lysforurensning I Arktis kan ha ødelagt forskningsresultater. Gemini.no
Popular scientific article
Ringvold, Halldis; Taite, Morag; Allcock, A. Louise; Vecchione, Michael; Péan, Michel; Sandulli, Roberto. (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
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
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 scientific article
Bazilchuk, Nancy Reney; Stahl, Annette; Johnsen, Geir; Saad, Aya; Thu, Maren; Nøland, Annecken. (2021) Sporhunden som lukter mikroalger. . Gemini.no
Popular scientific article
Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan H.; Mckee, David. (2021) All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic. Applied Optics
Academic article
Geoffroy, Maxime; Langbehn, Tom Jasper; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault. (2021) Pelagic organisms avoid white, blue, and red artificial light from scientific instruments. Scientific Reports
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; 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
Ramirez-Llodra, Eva; Hilário, Ana; Paulsen, Emil; Costa, Carolina; Bakken, Torkild; Johnsen, Geir. (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
Gibbens, Sarah; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2020) As the Arctic warms, light pollution may pose a new treat to marine life. . National Geographic
Interview Journal
Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.. (2020) Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth. Communications Biology
Academic article
Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole. (2020) Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer. Oceanography
Academic article
Fragoso, Glaucia Moreira; 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
Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan. (2020) Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots. Remote Sensing
Academic article
Fragoso, Glaucia Moreira; Davies, Emlyn John; Ellingsen, Ingrid H.; Chauton, Matilde Skogen; Fossum, Trygve Olav; Ludvigsen, Martin. (2019) Physical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspot. Progress in Oceanography
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; 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
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; Fragoso, Glaucia Moreira; 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 scientific article
Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Davies, Emlyn John; Ullgren, Jenny; Mendes, Renato; Johnsen, Geir. (2019) Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Science robotics
Academic article
Fragoso, Glaucia Moreira; 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
Fragoso, Glaucia Moreira; 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
Dumke, Ines; Nornes, Stein Melvær; Purser, Autun; Marcon, Yann; Ludvigsen, Martin; Ellefmo, Steinar Løve. (2018) First hyperspectral imaging survey of the deep seafloor: High-resolution mapping of manganese nodules. Remote Sensing of Environment
Academic article
Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning - enda en kilde til bekymring. Svalbardposten
Feature article
Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning truer livet i Arktis. Aftenposten Viten
Feature article
Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; De La Torre, Pedro R.; Nornes, Stein Melvær. (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
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
Fossum, Trygve Olav; Eidsvik, Jo; Ellingsen, Ingrid H.; Alver, Morten; Fragoso, Glaucia Moreira; Johnsen, Geir. (2018) Information-driven robotic sampling in the coastal ocean. Journal of Field Robotics (JFR)
Academic article
Kauko, Hanna Maria; Olsen, Lasse Mork; Duarte, Pedro; Peeken, Ilka; Granskog, Mats A.; Johnsen, Geir. (2018) Algal colonization of young arctic sea ice in spring. Frontiers in Marine Science
Academic article
Dumke, Ines; Purser, Autun; Marcon, Yann; Nornes, Stein Melvær; Johnsen, Geir; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports
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
Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert. (2018) Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic. Polar Biology
Short communication
Johnsen, Geir; Norli, Marit; Moline, Mark A.; Robbins, Ian; Quillfeldt, Cecilie von; Sørensen, Kai. (2018) The advective origin of an under-ice spring bloom in the Arctic Ocean using multiple observational platforms. Polar Biology
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
Gabrielsen, Tove M.; Johnsen, Geir. (2018) Skogen på Svalbard. Svalbardposten
Popular scientific article
Otterlei, Inger; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin; Hareide, Nils Roar; Christensen-Dalsgaard, Signe. (2017) 300 000 sjøfugl er forsvunnet fra Runde. Sunnmørsposten
Interview Journal
Johnsen, Geir; Christiansen, Hanne H; Ravolainen, Virve; Reymert, Per Kyrre; Jenssen, Eva Therese; Arlov, Thor Bjørn. (2017) Utfordrende natur og sikkerhet på Svalbard. Svalbardposten
Feature 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
Kauko, Hanna Maria; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C.J.; Duarte, Pedro. (2017) Windows in Arctic sea ice: light transmission and ice algae in a refrozen lead. Journal of Geophysical Research (JGR): Biogeosciences
Academic article
Berge, Jørgen; Johnsen, Geir. (2017) Kunnskapshull om livet i Arktis i mørketiden. Aftenposten Viten
Feature article
Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John. (2017) Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic. Scientific Reports
Academic 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; Johnsen, Geir. (2017) Om bambus, spøkelseskreps og et Arktis i endring. Svalbardposten
Feature article
Berge, Jørgen; Johnsen, Geir. (2017) Superkommunisten. Svalbardposten
Feature article
Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) Opp fra polarnattens mørke. Aftenposten Viten
Feature article
Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) A bitter-sweet symphony. Svalbardposten
Feature 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
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; Johnsen, Geir; Ludvigsen, Martin; Cohen, Jonathan. (2016) Design for latskap - men med store muligheter. Svalbardposten
Feature article
Bondø, Tor-Hartvig; Johnsen, Geir; Berge, Jørgen. (2016) Fant yrende liv i polarnatta. VG : Verdens gang
Popular scientific article
Berge, Jørgen; Johnsen, Geir. (2016) Mørkets fyrster med påskrudd lys. Svalbardposten
Popular scientific article
Bazilchuk, Nancy Reney; Leite, Stein Roar; Johnsen, Geir; Kjeken, John; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2016) Bomber og buss på havbunnen. Gemini
Popular scientific 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 scientific 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 scientific article
Bjørgan, Espen Halvorsen; Johnsen, Geir; Kjeken, Jon; Ludvigsen, Martin. (2016) Fant buss på 600 m dybde. Adresseavisen
Popular scientific 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
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Kinderegg i polarnatten. Svalbardposten
Feature 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 scientific article
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Dark lords, werewolves and Indiana Jones in the polar night. Gemini (English edition)
Interview Journal
Krüger, Frida Jørstad; Johnsen, Geir; Kjeken, John; Ludvigsen, Martin. (2016) Gammel buss ble korallrev. NRK Viten
Popular scientific 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 scientific article
Haugstad, Tormod; Erdal, Ivar; Johnsen, Geir. (2016) Kameraet deres «kan bli det nye ekkoloddet». Nå er det norske selskapet i ferd med å lykkes. Teknisk Ukeblad
Interview Journal
Johnsen, Geir. (2016) Yrende liv i Isfjorden. Svalbardposten
Popular scientific article
Aarskog, Karine Nigar; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2016) Et stort løft for arktisk forskning (NTNU & UiT). Universitetet i Tromsø
Article in business/trade/industry journal
Berge, Jørgen; Falk-Petersen, Stig; Renaud, Paul E.; Daase, Malin; Geoffroy, Maxime; Johnsen, Geir. (2016) En reise mot Ultima Thule. Svalbardposten
Popular scientific article
Lervik, Frank; Johnsen, Geir; Ludvigsen, Martin; Kjeken, John. (2016) Det ligger flere busser der. Adresseavisen
Popular scientific article
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Mark spiser opp vrak på havbunnen. Fiskaren
Popular scientific article
Kintisch, Eli; Berge, Jørgen; Last, Kim; Cohen, Jonathan; Johnsen, Geir. (2016) Voyage into darkness . Science
Interview Journal
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Ludvigsen, Martin; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Mørkets fyrster, varulver og Indiana Jones. Gemini
Popular scientific article
Berge, Jørgen; Renaud, Paul E.; Johnsen, Geir; Darnis, Gerald; Geoffroy, Maxime; Daase, Malin. (2016) I grenselandet (mellom Tull og Thule). Svalbardposten
Popular scientific article
Førde, Henny; Forbord, Silje; Handå, Aleksander; Fossberg, Julia; Arff, Johanne; Johnsen, Geir. (2016) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. Journal of Applied Phycology
Academic article
Nilssen, Ingunn; Dos Santos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo M.; Eide, Ingvar. (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
Nilssen, Ingunn; Santos dos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral Montenegro, Marcelo; Eide, Ingvar. (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
Rodriguez, Francisco; Garrido, J.L.; Sabrino, C; Johnsen, Geir; Riobo, P; Franco, J. (2015) Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae). Environmental Microbiology
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
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig. (2015) Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?. PLOS ONE
Academic article
Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.. (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. (2015) Unexpected levels of biological activity during the polar night offer new perspectives on a warming Arctic. Current Biology
Academic article
Pettersen, Ragnhild; Johnsen, Geir; Bruheim, Per; Andreassen, Trygve. (2014) Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms. Organisms Diversity & Evolution
Academic article
Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti. (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
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
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
Hansen, Ingrid; Pettersen, Ragnhild; Beuchel, Frank; Cochrane, Sabine; Frantzen, marianne; Ekehaug, Stefan. (2014) Underwater hyperspectral imaging (UHI) for environmental mapping and monitoring of seabed habitats. Ocean Optics
Abstract
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
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
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
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
Abstract
Nilssen, Ingunn; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen; Nornes, Stein Melvær. (2014) Integrated environmental monitoring; a methodological approach to optimise knowledge gathering and sampling strategy. Ocean Optics
Abstract
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
Errata
Berge, Jørgen; Cottier, Finlo; Varpe, Øystein; Renaud, Paul; Falk-Petersen, Stig; Kwasniewski, Sawomir. (2014) Arctic complexity: A case study on diel vertical migration of zooplankton. Journal of Plankton Research
Academic article
Hancke, Kasper; Hovland, Erlend Kjeldsberg; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark A.. (2014) Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance. Journal of Marine Systems
Academic article
Hovland, Erlend Kjeldsberg; Hancke, Kasper; Alver, Morten; Drinkwater, Kennneth F.; Høkedal, Jo; Johnsen, Geir. (2014) Optical impact of an Emiliania huxleyi bloom in the frontal region of the Barents Sea. Journal of Marine Systems
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; Falk-Pettersen, Stig. (2013) Mørkets hemmeligheter. Svalbardposten
Popular scientific article
Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir. (2013) Molecular and photosynthetic responses to prolonged darkness and subsequent acclimation to re-illumination in the diatom Phaeodactylum tricornutum. PLOS ONE
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; Båtnes, Anna Solvang; Johnsen, Geir; Blackwell, Susan; Moline, Mark A.. (2012) Bioluminescence in the high Arctic during the polar night. Marine Biology
Academic article
Gabrielsen, Tove M; Quillfeldt, Cecilie von; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden. Svalbardposten
Reader opinion piece
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
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
Volent, Zsolt; Johnsen, Geir; Hovland, Erlend Kjeldsberg; Folkestad, Are; Olsen, Lasse Mork; Tangen, Karl. (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
Jouenne, Fabien; Eikrem, Wenche; Le Gall, F; 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
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
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/
Abstract
Johnsen, Geir; Søreide, Fredrik. (2010) Underwater hyperspectral imaging of marine mineral deposits. Underwater Mining meeting Institute (UMI)
Abstract
Berge, Jørgen; Cottier, Finlo; Last, Kim S.; Varpe, Øystein; Leu, Eva; Søreide, Janne. (2009) Diel vertical migration of Arctic zooplankton during the polar night. Biology Letters
Academic article
Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Winge, Per; Hancke, Kasper; Andresen, Kjersti. (2009) An integrated analysis of molecular acclimation to high light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Academic article
Berge, Jørgen; Lønne, Ole Jørgen; Renaud, Paul; Johnsen, Geir; Gulliksen, Bjørn; Varpe, Øystein. (2009) Polartorsken - vil den bli utkonkurrert av sørlige fiskearter?. Svalbardposten
Popular scientific 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, Z; Johnsen, Geir; Sigernes, Fred. (2009) Microscopic hyperspectral imaging used as a bio-optical taxonomic tool for micro- and macroalgae. Applied Optics
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
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
Bakken, Torkild; Evertsen, Jussi; Johnsen, Geir. (2008) Vitenskapelig dykking - behov for endringer i forskriften. Dykkenytt : informasjonsorgan for dykkeindustrien
Article in business/trade/industry journal
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
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combined use of AUV and hyperspectral imaging to mapping sea-surface and macroalgae. Ocean Optics
Abstract
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
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
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
Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir; Naustvoll, L. (2007) Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology
Academic article
Johnsen, Geir. (2007) Arctic Life: Bridging ecosystem function using remote sensing technologies. Svalbard Science Forum
Popular scientific 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
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Editorial
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
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
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
Johnsen, Geir. (2006) Warming Arctic sees return of blue mussels after 1000 years. National Geographic
Popular scientific article
Onstad, L; Evertsen, Jussi; Johnsen, Geir. (2006) Snegle på solceller. Gemini
Popular scientific 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
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
Bordvik, Hans Otto; Johnsen, Geir. (2005) “En glupsk nellik”. NEWTON websider (NRK)
Popular scientific article
Indergaard, M; Nordtvedt, M; Johnsen, Geir. (2005) Satellittmålinger for miljøet (SISCAL project, NTNU, IBI). Gemini
Popular scientific article
Bordvik, Hans Otto; Johnsen, Geir. (2005) “Forskning og foto under vann”. NEWTON websider (NRK)
Popular scientific 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
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
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
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
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
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
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
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
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
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
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
Graneli, Edna; Legrand, Catherine; Carlsson, Per; Johnsen, Geir; Maestrini, Serge Y.; Reichelt, Michael. (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
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
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; 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
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
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
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
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
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
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
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
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; Sakshaug, Egil. (1995) Light harvesting in bloom-forming marine phytoplankton: species-specificity and photoadaption. Scientia Marina
Academic article
Egeland, E.; Johnsen, Geir; Eikrem, W.; Liaaen-Jensen, S.; Throndsen, J.. (1995) The pigments of Bathycoccus prasinos. Journal of Phycology
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
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
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
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
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
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
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
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
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; Sakshaug, Egil; Vernet, Maria. (1992) Pigment composition, spectral characteriation and photosynthetic parameters in Chrysochromulina polylepis. Marine Ecology Progress Series
Academic article
Johnsen, Geir. (1991) Proceedings from a scientific working meeting. Fisken og Havet
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
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

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

Books

Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Polar night marine ecology - life and light in the dead of night. Springer Advances in Polar Ecology (0)
Academic anthology/Conference proceedings
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2012) Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2012)
Academic anthology/Conference proceedings
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2011)
Academic anthology/Conference proceedings
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit M.. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Non-fiction book
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Academic anthology/Conference proceedings
Sakshaug, E.; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Textbook
Sakshaug, Egil; Johnsen, Geir. (2005) Algal cultures, Analogues of Blooms and Applications. Multi-Science Publishing Multi-Science Publishing
Academic anthology/Conference proceedings
Syvertsen, E.; Hegseth, E; Johnsen, Geir; Sakshaug, Egil; Gulliksen, B; Lønne, O. J. (1992) Livet i isen (The life in the ice). In Økosystem Barentshavet. [Mangler utgivernavn]
Non-fiction book
Sakshaug, Egil; Kristiansen, S; Syvertsen, E; Eilertsen, H. C; Gilstad, M; Hegseth, E. N. (1992) Planktonalger (Phytoplankton). In Økosystem Barentshavet. [Mangler utgivernavn]
Non-fiction book

Part of book/report

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/article/Conference paper
Berge, Jørgen; Johnsen, Geir. (2020) Life and Light at the Dead of Night. Springer
Academic chapter/article/Conference paper
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr. (2020) Light in the Polar Night. Springer
Academic chapter/article/Conference paper
Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H.. (2020) Operative Habitat Mapping and Monitoring in the Polar Night. Springer
Academic chapter/article/Conference paper
Johnsen, Geir; Leu, Eva; Gradinger, Rolf. (2020) Marine Micro- and Macroalgae in the Polar Night. Springer
Academic chapter/article/Conference paper
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Introduction. Springer
Introduction
Pavlov, Alexey K.; Leu, Eva; Hanelt, Dieter; Bartsch, Inka; Karsten, Ulf; Hudson, Stephen. (2019) The Underwater Light Climate in Kongsfjorden and Its Ecological Implications. Springer
Academic chapter/article/Conference paper
Zolich, Artur Piotr; De La Torre, Pedro R.; Rodwell, Shane; Geoffroy, Maxime; Johnsen, Geir; Berge, Jørgen. (2018) An ice-tethered buoy for fish and plankton research. IEEE conference proceedings
Academic chapter/article/Conference paper
Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur. (2015) Underwater vehicles for environmental management in coastal areas. IEEE conference proceedings
Academic chapter/article/Conference paper
Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik. (2014) Managing data from multiple sensors in an interdisciplinary research cruise. Amsterdam University Press
Academic chapter/article/Conference paper
Johnsen, Geir; Volent, Zsolt; Dierssen, Heidi; Pettersen, Ragnhild; Ardelan, Murat Van; Søreide, Fredrik. (2013) Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties. Woodhead Publishing Limited
Academic chapter/article/Conference paper
Ludvigsen, Martin; Johnsen, Geir; Lågstad, Petter Arthur; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord. IEEE conference proceedings
Academic chapter/article/Conference paper
Brunet, Christophe; Johnsen, Geir; Lavaud, Johan; Roy, Suzanne. (2011) Pigments and photoacclimation processes. Cambridge University Press
Academic chapter/article/Conference paper
Johnsen, Geir; Bricaud, Annick; Nelson, Norman; Prézelin, Barbara; Bidigare, Robert. (2011) In vivo bio-optical properties of phytoplankton pigments. Cambridge University Press
Academic chapter/article/Conference paper
Johnsen, Geir; Moline, Mark; Pettersson, Lasse H.; Pinckney, J. L.; Pozdnyakov, Dmitry; Egeland, Einar Skarstad. (2011) Optical monitoring of phytoplankton bloom pigment signatures. Cambridge University Press
Academic chapter/article/Conference paper
Llewellyn, Carole A.; Roy, Suzanne; Johnsen, Geir; Egeland, Einar Skarstad; Chauton, Matilde ; Hallegraeff, Gustaff. (2011) Perspectives on future directions. Cambridge University Press
Academic chapter/article/Conference paper
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Preface. Cambridge University Press
Foreword
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Acknowledgements. Cambridge University Press
Other
Johnsen, Geir; Volent, Z; Sakshaug, E.; Sigernes, Fred; Pettersson, L.H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
Sakshaug, E.; Johnsen, Geir; Kristiansen, Svein; Quillfeldt, C.v.; Rey, F.; Slagstad, D.. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
Sakshaug, E.; Johnsen, Geir; Volent, Z. (2009) Light. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
Quillfeldt, C.v.; Hegseth, E.N.; Johnsen, Geir; Sakshaug, E.; Syvertsen, E.E.. (2009) Ice algae. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
von Quillfeldt, Cecilie H.; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik. (2009) Ice algae. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
von Quillfeldt, Cecilie; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik E.. (2009) Ice algae. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
Sakshaug, Egil; Johnsen, Geir; Kristiansen, Svein; von Quillfeldt, Cecilie; Rey, Francisco; Slagstad, Dag. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
Sakshaug, Egil; Johnsen, Geir; Volent, Z.. (2009) Light. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
Johnsen, Geir; Volent, Zsolt; Sakshaug, Egil; Sigernes, Fred; Pettersson, Lasse H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
Academic chapter/article/Conference paper
Sakshaug, Egil; Johnsen, Geir. (2005) Absorption, fluorescence excitation and photoacclimation in phytoplankton. Multi-Science Publishing
Academic chapter/article/Conference paper
Johnsen, Geir; Samset, O.; Sakshaug, Egil. (1998) Bio-optical classification of potential harmful chlorophyll c -containing prymnesiophyte blooms in Scandinavian water.
Academic chapter/article/Conference paper
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/article/Conference paper
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/article/Conference paper

Report

Nøland, Annecken; Johnsen, Geir; Aberle-Malzahn, Nicole. (2022) Autonomous Underwater Vehicle (AUV) based study of zooplankton communities, using a silhouette camera and artificial intelligence. NTNU
Masters 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. NTNU
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters thesis
Bjerkvoll, Mikkel; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Aerial and underwater hyperspectral imagery for shallow benthic nature type mapping. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters 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. Doktoravhandlinger ved NTNU (2021-254)
Doctoral dissertation
Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2021) Underwater hyperspectral imaging as a tool for benthic habitat mapping. Doktoravhandlinger ved NTNU (2021/271)
Doctoral dissertation
Graham, Lisa Kristine Hernandez; Johnsen, Geir; Christensen-Dalsgaard, Signe. (2019) A pilot study assessing drones for mapping and monitoring of European shags. Institutt for biologi, NTNU
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters thesis
Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin; Hansen, Roy Edgar; Maarleveld, Thijs. (2018) Towards Autonomous Operations and Systems in Marine Archaeology. Doktoravhandlinger ved NTNU (IMT-12)
Doctoral dissertation
Strømsholm, Jørgen; Johnsen, Geir; Ludvigsen, Martin. (2018) Eyes beneath the surface - using a miniROV to reveal habitat and dietary choices of the European shag. NTNU MSc thesis
Masters thesis
Kauko, Hanna Maria; Johnsen, Geir; Assmy, Phillipp. (2018) Light response and acclimation of macroalgae in a changing Arctic. Doktoravhandlinger ved NTNU (2018)
Doctoral dissertation
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. Doktoravhandlinger ved NTNU (2018:202)
Doctoral dissertation
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. NTNU Trondheim
Masters 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. NTNU, Trondheim
Masters 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. NTNU, Trondheim
Masters 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. Master science NTNU
Masters thesis
Andersson, Ingvild Henriette Kristin; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin. (2017) Bio-optical diversity on cold water coral habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters 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 Norges teknisk-naturvitenskapelige universitet
Masters 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. NTNU
Masters 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
Masters thesis
Liefmann, Stephanie; Johnsen, Geir; Järnegren, Johanna. (2016) Eco-physiological responses of cold-water corals to anthropogenic sedimentation and particle shape. NTNU Mastergrad
Masters thesis
Lund, Le

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Geir Johnsen

Geir Johnsen

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