Einfluss von Fischerei und Klima auf die Bestände des antarktischen Krill

• Main Author: Siegel, Volker
• Format: Book Part
• Language: German
• Published: Wissenschaftliche Auswertungen 2014
• Subjects: Text; Antarctic; Southern Ocean; The Antarctic; Antarctic Peninsula; Indian; Antarc*; Antarctic Krill; Antarktis*; Euphausia superba; Sea ice
• Online Access: https://www.openagrar.de/receive/timport_mods_00013194; https://www.openagrar.de/servlets/MCRFileNodeServlet/timport_derivate_00013194/dn053373.pdf

The Antarctic krill, Euphausia superba, is the key species of the Antarctic food web. Since 1973 krill are commercially exploited. Following scientific biomass surveys, a catch limit has been set at 5.614 million tonnes for the Atlantic sector of the Southern Ocean and approx. at 3 million tonnes for the entire Indian sector. Although the current catch level of around 150,000 tonnes is not thought to cause negative effects on the overall krill stock, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) decided an interim precautionary measure that the krill catches in the Atlantic shall not exceed an operational catch limit (»trigger level«) of 620,000 tonnes. The strong overlap in the distribution of fisheries and krill predator colonies requires different management regulations and a procedure to apportion the overall catch limit to small-scale management units (SSMU). The feedback management should also consider climate effects on krill stocks, since successful reproduction and recruitment was found to be dependent on the extent of winter sea-ice cover. Long-term data analysis has shown a substantial decline in krill biomass since the early 1980’s. The recorded temperature increase in the Antarctic Peninsula region will result in a further decline of the winter sea ice and, hence, negatively affect the size of the krill stocks and dependent predator populations.