Population genetics of marine organisms

– Mork Lab

Our main research area is population structure, biology and ecology of  marine fishes. The current research project is on the genetic effects of net-spawning and escape from a cod aquaculture plant on the genetic constitution of the local Trondheimsfjord. Cod stock is being studied in detail using a broad range of genetic markers; blood proteins, allozymes, mtDNA, microsatellites and nuclear RFLP.


Applied population genetics and fisheries biology studies for the identification, description and delineation of stocks of commercially important marine fish species in the Atlantic. Main tools are electrophoretic markers (blood proteins, isozymes and DNA), tagging/recapture experiments and transplantation experiments for the study of migration/homing. Natural populations are described with respect to genetic characteristics, individual growth rates, gonad maturation dynamics, spawning time, stock recruitment, stock size estimates and relative year-class strengths.


Study materials include an extensive time series (~40 years, or 10 consecutive cod generations) of samples of the Trondheimsfjord cod stock, a geographic baseline collection covering 50 locations on the mid- and north Norwegian coast for cod and five other gadoid species.


The lab produced the first quantitative estimates of genetic variation in all the commercially most important gadoid- and flatfish species, and herring in the North-East Atlantic. For the gadoids cod, blue whiting, hake and poor cod the population genetic data cover their entire distribution ranges in the North Atlantic. Since the year 2000, the effects of increasing water temperatures on the planktonic ecology of the Trondheimsfjord and the recruitment dynamics of the local cod stock as well as of the invasive jellyfish Periphylla periphylla are being monitored by population genetic, biological, hydrographical and bottom trawl series.


  • Jarle Mørk - Mork lab




  • Trawl sample




  • Jellyfish - Periphylla




  • Periphylla catch at Gunnerus R/V




  • Population genetics studies




  • Dendrogram showing the genetic structure






Jarle Mørk

Jarle Mork


E-mail: jarle.mork@ntnu.no

Collaborators (partial list)

Prof. Einar Arnason, Dr. Gudni Magnusson (University of Iceland)

Prof. Einar Eeg Nielsen, Dr. Stine Dalmann Ross, Dr. Keith Brander (Denmark Technological University (DTU))

Prof. John Fleng Steffensen (University of Copenhagen, Denmark)

Dr. Olav Rune Godø, Dr. Mikko Heino, Dr. Anders Jelmert, Dr. Torild Johansen (Institute of Marine Research, Bergen, Norway)

Dr. Elizabeth Gosling (Galway-Mayo Institute of Technology, Galway, Ireland)

Prof. Jean-Francois Rees (Universite de Lovain, Belgium)

Ass. Prof. Bryan Grieg Fry, Dr.Eivind Undheim (University of Queensland, Australia)

Dr. Ingebrigt Uglem (NINA, Trondheim, Norway)

Dr. Rachel Tiller, Yajie Liu, Øyvind Knutsen, Lionel Eisenhauer (Sintef Fisheries and Aquaculture, Trondheim, Norway)

Prof. Ulf Båmstedt (University of Umeå, Sweden)

Dr. Oddvar Longva (NGU, Trondheim)

Prof. Petr Strelkov (St. Petersburg State University, St-Petersburg 199178, Russia)

Dr. Mark Baumgartner (Woods Hole Oceanographic Institution,USA)