Krill, Climate, and Contrasting Future Scenarios for Arctic and Antarctic Fisheries

No abstracts are to be cited without prior reference to the author.

Arctic and Antarctic marine systems have in common high latitudes, large seasonal changes in light levels, cold air/ sea temperatures, and sea ice. In other ways they are strikingly different, including: geological structure; ice stability; and food webs. Both regions contain rapidly warming areas; reported climate impacts and future projections are dramatic. Effects of changing climate on oceanographic processes and food webs influence their fisheries in different ways. Life-history strategies of zooplankton (Antarctic krill and Calanus copepods in the Arctic) may affect future fisheries productivity. To explore potential future scenarios for each region; this paper: 1) considers characteristics (geographic, physical, biological) defining these ecosystems, and reviews impacts of climate change on key zooplankton; 2) summarizes existing fisheries; 3) synthesizes this information to envisage future scenarios; 4) considers implications for management. Published studies suggest that in the Arctic increased open water and primary/ secondary production may benefit fish stocks. Fisheries may see new mixes of species and enhanced biomass. In contrast, studies in the Southern Ocean suggest the potential for existing species to adapt is mixed and potential for invasion of pelagic finfish is low. Future fisheries may depend on currently existing species. Management approaches should anticipate climate-induced changing dynamics in these regions