Ivory gulls eat contaminated food
The ivory gull, which is threatened by extinction, feeds on crustaceans and fish, but it also eats meat and blubber from carcasses, placing it high up in the food chain in the Arctic. Results from a recent study show how the concentration of environmental toxins in ivory gulls is related to their choices of food and feeding areas.
Temperature increase and sea ice melt will likely alter the transport and increase the amount of environmental contaminants in the Arctic. Such contaminants are often persistent and accumulate from one trophic level to another in the food chain. As a result, animals at the top of the food chain, such as seabirds, suffer especially from high levels of environmental contaminants. The ivory gull lives in ice-filled waters all the year round, and is thus very vulnerable to climate change-induced sea-ice melt and an increase of environmental contaminants in its food. In the present study, the relationship between the foraging strategy and the amount of persistent environmental contaminants, such as DDE, PCB and PFOS, was examined in ivory gulls breeding on Svalbard. Prey items from the higher levels of the food chain (e.g. fish versus shellfish) and shorter distances from the shoreline were found to increase the amount of environmental contaminants in the ivory gulls.
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Contact person: Hallvard Strøm, Norwegian Polar Institute
Photo: Vegard Bang Fjeldheim