Antarctic krill population contracts southward as polar oceans warm

The population of Antarctic krill, the favourite food of many whales, penguins, fish and seals, shifted southward during a recent period of warming in their key habitat, new research shows.

Antarctic krill are shrimp-like crustaceans which occur in enormous numbers in the cold Southern Ocean surrounding Antarctica. They have a major role in the food web and play a significant role in the transport of atmospheric carbon to the deep ocean.

Important krill habitats are under threat from climate change, and this latest research — published today (Jan. 21, 2019) in Nature Climate Change — has found that their distribution has contracted towards the Antarctic continent. This has major implications for the ecosystems that depend on krill.

An international team of scientists, led jointly by Dr Simeon Hill at the British Antarctic Survey and Dr Angus Atkinson at Plymouth Marine Laboratory, analysed data on the amount of krill caught in nets during scientific surveys. The data covered the Scotia Sea and Antarctic Peninsula — the region where krill are most abundant. The team found that the centre of the krill distribution has shifted towards the Antarctic continent by about 440 km (4° latitude) over the last four decades.

The team took great care to account for background noise in the data. Many factors, in addition to long-term change, influence the amount of krill caught in any one net. Even after accounting for these factors the team found a consistent trend throughout the data, indicating a substantial change in the krill population over time.

For More: https://www.sciencedaily.com/releases/2019/01/190122115024.htm

Posted by admin on Jan 24 2019. Filed under Climate change. You can follow any responses to this entry through the RSS 2.0. You can leave a response or trackback to this entry