Attempts at a quantitative estimate by trawl sampling of distribution of postlarval and juvenile notothenioids (Pisces, Perciformes) in relation to environmental conditions in the Antarctic Peninsula region during SIBEX 1983-84

摘要

During the SIBEX 1983-84 programme, an attempt was made at a quantitative estimate of the distribution of postlarval and juvenile fish north of the South Shetland Islands and the Palmer Archipelago, and in the Bransfield Straits by means of a 368-mesh sampling trawl, designed especially for this project. A total of 14 fish species at the postlarval and juvenile stages was found in the catches. The greatest abundance up to 928 individuals per hour of fishing was recorded within shelf waters of the Antarctic Peninsula. Postlarval and juvenile Pleuragramma antarcticum was the most common and most abundant species there. Relations between fish abundance and environment were observed in the area studied. A decrease in the abundance of juvenile Nototheniidae and Channichthyidae accompanied an increase in depth to the bottom. The abundant occurrence of Pleuragramma seemed to be influenced by the temperature and salinity of water.