Environmental Drivers of Antarctic Krill Distribution in the South Orkney Islands Region

Emma Frances Young1, Sally E Thorpe1, Eugene John Murphy1 and Angelika Renner2, (1)British Antarctic Survey, Cambridge, United Kingdom, (2)Institute of Marine Research Bergen, Bergen, Norway
Antarctic krill (Euphausia superba) is a key species in the marine ecosystem of the Southern Ocean, but is also the target of a commercial fishery, with an important fishing ground in the South Orkney Islands region. Development of risk management strategies for the fishery necessitates a deeper understanding of the key physical and behavioural drivers for krill distribution. Using a combination of regional oceanographic modelling and an Individual Based Model (IBM) parameterized for krill, we have investigated the influence of regional-scale oceanographic variability on patterns of transport and retention on and around the South Orkney Plateau. Incorporating behavioural traits relevant to krill into the IBM, specifically association with sea ice, significantly modified the patterns from purely oceanic transport; strong regional oceanic flows had a weaker influence on transport pathways, and local recruitment and retention tended to decrease. Here, we present the key findings of our research and highlight the importance of understanding the behaviour of krill, including age-dependent behavioural changes in response to sea ice conditions, for parameterization of more refined model simulations.