Presentation on theme: "Impact of marine climate variability and stock size on the distribution of Barents Sea capelin Randi B. Ingvaldsen and Harald Gjøsæter BARECORE annual."— Presentation transcript:
Impact of marine climate variability and stock size on the distribution of Barents Sea capelin Randi B. Ingvaldsen and Harald Gjøsæter BARECORE annual meeting Herdla 4-7 October, 2011
Motivation Earlier studies: When the capelin stock is large, the feeding area is expanded (Gjøsæter, 2000) In warm years the capelin migrate to the north- eastern Barents Sea (Loeng, 1981; Ushakov and Ozhigin, 1987) This study: Evaluate how the capelin distribution change taking into account stock size, ocean temperature and the amount of open water
Relation to stock size Adjusting for stock size Capelin meet the greater food demand by expanding its distribution
Relation to ocean temperature Since the mid/late 1990s the temperatures have been high enough to support a widespread capelin distribution
Conclusions Since the mid/late 1990s, there has been a shift in the capelin distribution because of high temperatures (and low ice cover) in the northern Barents Sea. An increase in stock size of 4 million tonnes and an increase in temperature of 1 o C give comparable impact on the distribution. To give reliable projections of climate-induced changes in the capelin distribution, the factors influencing the stock size (prey, predators, trophic interactions) must be included.