New refuge for Antarctic krill
New research shows that Antarctic krill, an important link in the Southern Ocean’s food web, has a refuge from rapid global warming and ice loss. These factors have already severely affected some of its habitat in the Atlantic part of the Southern Ocean.
It has long been assumed that the Atlantic sector of the Southern Ocean was the epicenter of the global krill population. This has raised alarm bells for conservation of their stocks, since this particular region has been one of the fastest warming ocean regions on the planet. This new research shows that, while this region can support fewer krill than before due to habitat degradation, the more stable Indian and Pacific sectors are acting as refuges, possibly even holding more krill than they did a century ago.
The study focused on a recent Chinese circumnavigation of Antarctica with a ring of stations where samples had been taken. This feat on the Xuelong icebreaker is probably unmatched today and offers the necessary circumpolar perspective, supported by an existing circumpolar database of krill from the last 90 years. Lead author of the study, Dr. Guang Yang, marine ecologist at the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), explains: “Most plankton species, including krill, are distributed in a ring right around Antarctica, but their habitats are changing at different rates from sector to sector. We used this as a kind of natural experiment to trace the changing fortunes of krill in each of the sectors.”
“The Southern Ocean is a huge and complex ecosystem. By pulling together multiple data sources from multiple locations we are beginning to see the bigger picture, which is that some areas have changed more rapidly than others.”
Dr. Simeon Hill, BAS
This study offers a broader circumpolar perspective on these krill stocks. A broader view is timely, as this type of information is needed to plan a network of marine protected areas (MPAs) in Antarctica and to carry out scientifically based management of various fisheries. Co-author Dr Simeon Hill, fisheries modeller at the British Antarctic Survey (BAS), said: “The Southern Ocean is a huge and complex ecosystem. By pulling together multiple data sources from multiple locations we are beginning to see the bigger picture, which is that some areas have changed more rapidly than others.” So more data is needed to collect on how krill populations will continue to behave. However, in order to be able to accomplish this task, international cooperation such as this is increasingly necessary. Co-author Dr Angus Atkinson, senior ecologist at Plymouth Marine Laboratory, said: “This is a great example of how the different nations working in Antarctica can combine their ideas and data. A spirit of cooperation is essential for a common approach to management and conservation in Antarctica.”
Dr Michael Wenger, PolarJournal / Source: Press release by British Antarctic Survey
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