Fish Stocks in the southern Scotia Arc region – a review and prospectus Antarctic predator response to fish depletion D

We provide a summary of biological aspects and population trends of demersal finfish stocks in the southern Scotia Arc region of Antarctica. Information presented here, drawn largely from recent scientific research surveys, includes aspects of species composition, biomass and stock structure, reproduction and early life history, age, growth, and nat-ural mortality, and diet. Although Antarctic fish faunal groups overlap in the southern Scotia Arc, the region is dominated by species of low-Antarctic origin both in terms of biomass and number of species. Several basic biological parameters of the abundant fish species in the southern Scotia Arc are comparatively well known, though less so in the South Orkney Islands than the South Shetland Islands. These stocks suffered substantial declines as a result of commercial exploitation of mackerel ice fish, Champsocephalus gunnari, and marbled notothenia, Notothenia rossii, in the late 1970s and mid 1980s. This led to a moratorium on directed fishing in 1989–90 which remains in effect. At present, several stocks, with the exception of these two species, appear to have recov-ered. A number of important biological features, such as age, growth, mortality, and the early life history of most species are still poorly understood. Key biological research needs are identified