PhD trial lecture and public defence: Marvin Choquet

05 December 2017 10:15 - 05 December 2017 15:30

Auditorium Petter Thomassen (A5)

PhD-candidate Marvin Choquet will hold a trial lecture and defend his thesis for the degree Philosophiae Doctor (PhD), at the Faculty of Biosciences and Aquaculture, Nord University.

Ph.d.-candidate: Marvin Choquet

Title of thesis:
Combining ecological and molecular approaches to redefine the baseline knowledge of the genus Calanus in the North Atlantic and the Arctic Oceans

Title of trial lecture:
What makes the Calanus genus so successful in boreal and Arctic food webs?

Time of trial lecture: 10:15 - 11:15
Time of defence: 12:15 - 15:30
Place: Auditorium Petter Thomassen (A5)

Members of the evaluation committee:
- Assistant Scientist (PhD) Leocadio Blanco-Bercial
  Bermuda Institute of Ocean Sciences, Bermuda
- Assistant Professor Fredrika Norrbin, Department   of Arctic and Marine Biology, UiT, Tromsø  
- Assistant Professor Henning Reiss, FBA, Nord     University (leader).

Main supervisor: Professor Galice Hoarau, FBA
Co-supervisor: Assistant Professor Janne E. Søreide, Universitetssenteret på Svalbard, Svalbard 

The PhD trial lecture and defence are open to the public. The thesis is available on request. Please contact Jeanett Stegen, email:, phone: 75 51 74 49 

About the thesis:
DNA, key to understand Calanus: To better understand the ecologically important zooplankton genus Calanus, Marvin combined ecological and molecular approaches to establish a solid knowledge baseline for these climate indicator species.

Using DNA as a main tool, Marvin redefined the distributions of each of the four Calanus species inhabiting the North Atlantic and the Arctic Oceans. He demonstrated that DNA is the only way to reliably identify species, and showed that misidentification has been common. He evaluated the potential for hybridisation among species and used molecular tools to discard this hypothesis. Further, he developed new genomic resources, to be used as tools to study Calanus population connectivity and evolutionary history.

The new knowledge documented in this thesis will help to better understand the impact of climate change in
Calanus at population, species and ecosystem level. Furthermore, it challenges the current understanding of fjord ecosystems and questions the ecological role of each species.


Although Calanus species are among the most studied organisms within the zooplankton, little is known about species distribution and boundaries as well as gene flow between populations. Such knowledge is essential to understand their ecology and to predict responses to climate change. 

Marvin will present his thesis for the degree of Philosophiae Doctor, entitled "Combining ecological and molecular approaches to redefine the baseline knowledge of the genus Calanus in the North Atlantic and the Arctic Oceans" on the 5th of December 2017 at Nord University.