Direct effects of climate change on the Antarctic krill fishery

Climate change is predicted to affect marine fisheries, but these effects are usually considered to be indirect, for example through distributional changes in fish populations (Perry, Low, Ellis & Reynolds 2005), changes in marine biodiversity (Cheung, Lam, Sarmiento, Kearney, Watson & Pauly 2009) or changes in oceanic productivity (Sharp 2003). This article shows that in Antarctic waters, there is already evidence of direct effects of the changing physical environment – the duration of sea ice cover – on the seasonal behaviour of the region's largest fishery, that for Antarctic krill, Euphausia superba (Kock, Reid,Croxall & Nicol 2007). Declining sea ice cover in the main krill fishing grounds has resulted in greater accessibility of krill stocks to the fishing fleets, particularly during winter, and this change in fishing behaviour will need careful management in an era of rapid ecological change.