Antarctic krill: Key food source moves south
https://www.bbc.com/news/science-environment-46953652
Antarctic krill: Key food source moves south
By Jonathan Amos
BBC Science Correspondent
21 January 2019
A keystone prey species in the Southern Ocean is retreating towards the Antarctic because of climate change. Krill are small, shrimp-like creatures that swarm in vast numbers and form a major part of the diets of whales, penguins, seabirds, seals and fish.
Scientists say warming conditions in recent decades have led to the krill contracting poleward. If the shift is maintained, it will have negative ecosystem impacts, they warn. Already there is some evidence that macaroni penguins and fur seals may be finding it harder to get enough of the krill to support their populations.
"Our results suggest that over the past 40 years, the amount of krill has, on average, gone down, and also the location of the krill has contracted to much less of the habitat. That suggests all these other animals that eat krill will face much more intense competition with each other for this important food resource," Simeon Hill from the British Antarctic Survey told BBC News.
The study is published in the journal Nature Climate Change. It focuses on the Scotia Sea and the Antarctic Peninsula - the places where the crustaceans are most abundant. Scientists have been gathering data in these areas since the 1920s. Initially, krill catches were recorded to understand the environmental consequences of commercial whaling, but the information has continued to be collected through to the present.
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