Exploring the effects of reductions in krill biomass in the Southern Ocean on blue whales using a state-dependent foraging model

• Published in: Ecological Modelling
• Main Authors: Wiedenmann, J, Cresswell, KA, Goldbogen, J, Potvin, J, Mangel, M
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Science Bv 2011
• Subjects: Mathematical Sciences; Applied Mathematics; Biological Mathematics; Southern Ocean; baleen whales; Blue whale; Sea ice
• Online Access: https://doi.org/10.1016/j.ecolmodel.2011.07.013; http://ecite.utas.edu.au/131160

Many species of baleen whales were hunted to near extinction in the Southern Hemisphere. The recoveryof these populations will be affected by the availability of krill, a major dietary component, in the SouthernOcean. We combine a novel energetics model for baleen whales with a state dependent foraging modelto explore the impacts of an expanding krill fishery on baleen whales. We parameterize the model forblue whales, but with simple modifications it could be applied to most baleen whales. We predict thatan expanding fishery will have a small but significant impact on the blue whale population throughdecreased birth rates. However, spreading the catch limit throughout the range of krill can reduce theseeffects. In addition, whales may be able to reduce these impacts through adaptive changes in foragingbehavior. The relationship between krill abundance and blue whale foraging and reproductive successis nonlinear, such that larger reductions in krill biomass, potentially following a loss of sea ice due toclimate change, could have a much larger negative impact on the recovery of blue whales.