Will Climate Change Affect the Sustainability of Krill Fishing? A Simulation Study.

In the Southern Ocean, Antarctic krill form the base of the food web, and are the primary food source for a wide range of species, including whales, penguins and fish. Krill also comprises the largest fishery resource in Antarctica, but are increasingly thought to be impacted by changing environmental conditions associated with climate change. In order to explore potential synergistic impacts of climate change on krill and Antarctic food webs, we created a model to simulate the growth dynamics of Antarctic krill and its predators under changing sea surface temperatures, sea ice and fishing conditions. However, climate change and fishing are predicted to synergistically interact, possibly shrinking the average krill body sizes. Simulations of predator dynamics also showed that the effects of increased fishing under climate change will initially impact predator populations, rather than krill populations. Further, our empirically constrained simulations indicate that the total predation per year on krill is likely higher than previously assumed. These results can help drive further investigations on krill and predator population dynamics in a changing climate.