John Fleng Steffensen, Professor
M.Sc., lic. scient (Ph.D.)

University of Copenhagen
Marine Biological Section, Department of Biology
Strandpromenaden 5, DK-3000 Helsingør


Telephone - direct : +45 353 21986    Cell Phone: +45 60770490
e-mail primary :   
JFSteffensen @

e-mail secondary: JFSteffe @



ORCID: 0000-0002-4477-8039


Main Project: Old And Cold: Biology of the Greenland shark


Other projects: "Atlantic Bluefin Tuna Research" w IFREMER, France 2020 - 2025.



Link to 5 min video concerning the project - open in other window:


Other project: Behaviour and physiology of billfish - sailfish, marlin, spearfish and swordfish:


High-speed video of sailfish slashing a sardine school - recorded at 240 frames pr. second - replayed in slow-motion at about 10 times lower speed.

Heli fishing trip with US Navy and baited traps south of McMurdo Station in Antarctica on the ice at approximately 77,5 S - 165 E. The water was

about 700 meters deep and the ice +2 meters thick. Traps were deployed through Weddell Seal breathing hole. Foto: J. F. Steffensen.



Shark attacking baitfish at Heron Island, Great Barrier Reef, Australia. Photo:J. F. Steffensen.

Updated August 2023.