Per Juel Hansen Lab

Physiology and function biology of marine plankton

I am generally interested in physiology and function biology (ecology) of planktonic organisms, community structure and function of microbial communities in marine environments. Recently, I have worked on effects of acidification (low pH) as well as on alkalinification (elevated pH) on plankton organisms. While acidification of the sea is an effect of our use of fossil fuels, alkalinification occurs in fjords and embayments during algal blooms due to high primary production.

The focus of my research group is presently on 1) Toxic algae associated with fish kills. We work with natural product chemists to discover new algal toxins associated with fish kills, and with fish physiologists on the mechanisms behind fish kills and possible immunological reactions of fish towards algal toxins. Finally, we study the costs and benefits of toxin production of marine phytoplankton, 2) Mixotrophy, which is the ability of organisms to simultaneous photosynthesize and eat. We usually split plankton organisms in to phytoplankton (“plants”) and zooplankton (animals). However, we are now aware of that many plankton organisms are in fact mixotrophs. We study the functional biology and physiology in both “algae” that eat as well as “animals” that utilize chloroplasts, which they steal from their algal prey.





Name Title Phone E-mail
Per Juel Hansen Professor +4535321985 E-mail


Professor Per Juel Hansen
Marine Biology Section
Strandpromenaden 5
DK-3000 Helsingør, Denmark

Phone:  +45 35 32 19 85
Mobile: +45 26 78 21 17
Fax: +45 35 32 19 51

ORCID: 0000-0003-0228-9621




Name Title E-mail
Melanie Desmaret Walli
MSc student E-mail
Christine Schultz Yde Eriksen
MSc student
Emilie Frederikke K. Henningsen
MSc student E-mail