Conservation and Management of Antarctic Silverfish Pleuragramma antarctica Populations and Habitats

Abstract

One of the main conservation objectives for marine systems is to identify areas of ecological importance for biodiversity and essential species habitats which can be used as scientific reference areas for monitoring global change in the absence of major human impacts. The Antarctic silverfish, Pleuragramma antarctica is a keystone pelagic species, that has been assessed on the IUCN Red list of threatened species as a species with “Least Concern”. However, this species is unique as it is placed at one extreme of the notothenioid evolutionary/ecological axis that ranges from benthic to secondary pelagic life style. Its different life stages occur in unique environments such as the platelet ice for eggs, some of the inner shelf canyons for young larvae and at the shelf break with Antarctic krill swarms for juveniles and adults. The winter habitats are not known. In addition to the effects of climate change, a threat to this species is its bycatch in krill fisheries; however it has not been directly harvested since the 1980s. As a midtrophic species, P. antarctica is sensitive to environmental changes and should be monitored in protected scientific reference areas to obtain information on global change. For a midtrophic fish in a supposed wasp-waist ecosystem, strict regulation of bycatch and monitoring should be carried out in parallel with the monitoring of Antarctic krill and ice krill. The designation of protected areas is an important mechanism for preserving the essential habitats of P. antarctica in the Southern Ocean.