Prøveforelesning og disputas - MSc in Biology Olof Bengtsson

Later, at 12.15 he will defend his thesis entitled: "Dietary niches of phocid seals and predatory fishes in Kongsfjorden, Svalbard: Comparisons between co-occurring endemic Arctic and non-endemic species"

Head of department at AMB Vidar Sørum will lead the disputation.

Popular Science Summary
Kongsfjorden in Svalbard is transforming due to climate change. Sea ice is disappearing, glaciers are retreating, and southern species are taking over while Arctic species are declining. Stomach contents of fish and chemical compounds in skin and blubber from seals were used to explore diets of Arctic and non-Arctic species co-existing in Kongsfjorden. Dietary overlap was observed between Arctic char and pink salmon, polar cod and Atlantic cod, and between the Arctic ringed- and bearded seals and the temperate harbor seal. This suggests that there could be competition for food. Atlantic prey were common for species feeding pelagically and in central/outer Kongsfjorden, suggesting strong “Atlantification” in these habitats. Arctic prey still play vital roles in the food web, especially at the seabed and in inner Kongsfjorden. Relying on Arctic habitats and specialized diets could help Arctic predators in the short-term but are likely to be replaced by Atlantic species in the long-term.

Evaluation Committee

• Professor David Thomas, University of Helsinki, Finland (1. opponent)
• Senior researcher Dr. Marta Moyano, The research institute for water and the environment (2. opponent)
• Associate Professor Arve Lynghammar, Norwegian College of Fishery Science (Internal member and leader of the committee)

Supervisors

• Professor Jørgen Berge, AMB
• Senior researcher Dr Kit Kovacs, the Norwegian Polar Institute

Streaming

Both the trial lecture and defense and will be streamed and recorded:

• Trial lecture
• Defense

Thesis

 The thesis is available through Munin