A long-term decline in krill density is linked to winter sea ice
An analysis of decades of net-haul records from the Southern Ocean reports that krill density in the southwest Atlantic sector declined over the second half of the twentieth century, correlating with reduced winter sea-ice extent, while salps increased. It is the paper that made the krill-ice dependency a matter of measured record rather than of inference from life history, and the size of the decline has been argued over ever since.
Historical — it happened, and the record is settled.
Subjects
- Antarctic Krill (Euphausia superba) · species · Southern Ocean - circumpolar, south of the Antarctic Polar Front · not located
- Sea Ice · natural phenomenon · Both polar oceans · not located
- Southern Ocean · maritime region · Circumpolar, south of roughly 40°S · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
Long-term decline in krill stock and increase in salps within the Southern Ocean
Analysis of a compiled database of scientific net hauls indicates a long-term decline in Antarctic krill density in the southwest Atlantic sector, correlated with reduced winter sea-ice extent, together with an increase in salp abundance. V55 VERIFICATION BASIS: not opened during production; no research channel was available. The magnitude of the reported decline is deliberately not quoted anywhere in this pack, because subsequent work has contested it and the figure could not be checked.
Nature; Atkinson, Siegel, Pakhomov and Rothery · 2004 · Partly verified
Nature, vol. 432, pp. 100-103 (2004); doi:10.1038/nature02996
Recorded on Antarctic Krill (Euphausia superba)
- The factory ship Lancing takes a stern slipway south
- The Antarctic blue whale catch reaches its all-time peak
- The continuous satellite sea-ice record begins
- CCAMLR is agreed at Canberra
- The Southern Ocean Whale Sanctuary is adopted
- A long-term decline in krill density is linked to winter sea ice
- The Arctic summer minimum drops far below anything previously observed
- The lowest Arctic sea-ice extent in the satellite record
- Dedicated Antarctic Blue Whale Project voyages
- The Halley Bay emperor colony fails and does not recover
- CCAMLR adopts the Ross Sea marine protected area
- Baleen whale consumption is re-measured, and the krill paradox sharpens
- The emperor penguin is listed as threatened under the US Endangered Species Act
- The only published Antarctic blue whale satellite tracks are released as data
- Antarctic sea ice reaches a record low, a year after the previous one
- Antarctic meltwater is projected to slow the abyssal cell
- A physics-based early warning signal is proposed
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- A physics-based early warning signal is proposed · 2024-02
- The only published Antarctic blue whale satellite tracks are released as data · 2023
- Antarctic sea ice reaches a record low, a year after the previous one · 2023-02
- Antarctic meltwater is projected to slow the abyssal cell · 2023
- The emperor penguin is listed as threatened under the US Endangered Species Act · 2022-10-25
- Baleen whale consumption is re-measured, and the krill paradox sharpens · 2021-11
- The Halley Bay emperor colony fails and does not recover · 2016 onward
- CCAMLR adopts the Ross Sea marine protected area · 2016-10