Changes in biomass of eight species of finfish around the South Orkney Islands (Subarea 48,2) from three bottom trawl surveys

Stocks of finfish exploited around the South Orkney Islands (Subarea 48.2) suffered substantial declines from split-year 1977/78 to 1989/90. The biomass of several species of finfish has been monitored through scientific bottom trawl surveys within the 500 m isobath of the South Orkney Islands, most...

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Bibliographic Details
Main Authors: Jones, C.D., Kock, K.H., Balguerías-Guerra, Eduardo
Format: Article in Journal/Newspaper
Language:unknown
Published: 2000
Subjects:
Online Access:http://hdl.handle.net/10508/6966
http://hdl.handle.net/10261/325976
Description
Summary:Stocks of finfish exploited around the South Orkney Islands (Subarea 48.2) suffered substantial declines from split-year 1977/78 to 1989/90. The biomass of several species of finfish has been monitored through scientific bottom trawl surveys within the 500 m isobath of the South Orkney Islands, most recently by the Federal Republic of Germany in 1985, Spain in 1991 and the USA in 1999. From these surveys, estimates of total stock biomass were computed for the eight species of finfish which were most abundant in catches. Biomass levels and size composition from the March 1999 trawl survey were compared to previous surveys conducted in February 1985 and January to February 1991. Species examined were Gobionotothen gibberifrons, Lepidonotothen sqtlarnifrons, Pseudochaenichfhys georgianus, Charnpsocephalus gunnari, Chae~zocephalus aceratus, Chionodraco rastrospinosus, Notothenia rossii and Lepidonotothen larseni. Despite substantial variability in point estimates, biomass levels of most species appear to be unchanged or may have declined slightly since 1991. The stock of C. gzinnari is currently extremely low, while there appear to be strong signs of recovery for N. rossii. However, overall levels of biomass indicate very little potential for commercial exploitation at this tim No