The most important animal in the Arctic

The most important animal in the Arctic

Top image: The Calanus species is essential in the Arctic marine ecosystem. Photo: Daniel Vogedes/UNIS

Without copepods the entire Arctic marine ecosystem would probably collapse. They hold a key position in the food web as a link between phytoplankton and larger animals in the Arctic. In a new PhD thesis by Daniel Vogedes unknown life history aspects of three copepod species are revealed. Vogedes will defend his thesis at UNIS on Wednesday 19 November 2014.

17 November 2014
Press release from UNIS and UiT – The Arctic University of Norway.

The PhD thesis by Daniel Vogedes sheds light upon hitherto unknown aspects of the life history of three co-occurring and closely related copepod species (Calanus glacialis, C. finmarchicus and C. hyperboreus).

Essential animal in the marine ecosystem
These species are thought to be absolutely essential for the functioning of the Arctic marine ecosystem as we know it today. In particular the C. glacialis is probably the most important link between phytoplankton and sea birds, mammals and fish higher up in the food web.

Problems with identification of the three Calanus species, their role as food for little auks (the most numerous breeding sea bird in Svalbard), their energy content as well as the distribution of Calanus around Svalbard is in the focus of the thesis.

The thesis is built upon six scientific publications, each of them with focus on a different aspect of the life history of the three Calanus species, Calanus finmarchicus, C. glacialis and C. hyperboreus.

Using genetic methods Vogedes and colleagues were able to show that the traditional method of visual species identification is problematic and should be revised. They also found that the Calanus species can form dense aggregations on a small scale (1–2 km), which is important both for our understanding of the biology of Calanus, and even more so the feeding strategies of larger predators like the little auk.

Little auk (alle alle) in Svalbard

Little auk (alle alle) feeds mainly on Calanus. Photo: Eva Therese Jenssen/UNIS

A major finding discussed in the thesis is the fact the little auks alternate between long and short foraging trips to find food for their offspring and to replenish their own energy reserves with energy rich food far away from the bird colony in Bjørndalen, just outside Longyearbyen in Svalbard. This alternating feeding strategy seems to be directly linked to the Calanus distribution in the Isfjorden system.

Last, but not least, the scientists also found clear indications that Calanus do not perform any daily vertical migrations in autumn, as had been speculated before, but that there are daily vertical migrations of zooplankton (possibly Calanus) in the dark of the polar night.

Dissertation
Daniel Vogedes will defend his thesis for the PhD degree, titled “Calanus spp. in the Arctic ecosystem – a story on predation, distribution and morphology” on 19 November 2014 at 13:00 in the auditorium “Lassegrotta” at UNIS. He will hold a trial lecture entitled “The role of lipids in polar marine ecosystems” at 10:15 the same day at UNIS.

Daniel Vogedes

Daniel Vogedes

About the candidate:
Daniel Vogedes was born in Duisburg, Germany in 1974. He studied at the Christian-Albrechts-University in Kiel, Germany, before he took a one year undergraduate programme in biology at UNIS in 2001.

He immediately got bitten by the Svalbard virus and returned only a year later to do his master thesis at UNIS.

After various small jobs on the island he went back to science and started his PhD at UNIS in 2005. In the end of 2009 he moved to Tromsø and is at the moment working as a research technician at UiT – The Arctic University of Norway.

In addition he has a part-time job as secretary for the ARCTOS network, as well as a part-time position as field technician in the biology department at UNIS.

Read Daniel Vogedes’ PhD thesis here: Calanus spp. in the Arctic ecosystem – a story on predation, distribution and morphology

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