Monitoring of relative abundance of fjord Notothenia rossii, Gobionotothen gibberifrons and Notothenia coriiceps at Potter Cove, South Shetland Islands, in years 2000 to 2003

BARRERA-ORO E.; MARSCHOFF E.; CASAUX R,; GONZÁLEZ B.

Workshop; The CCAMLR Fish Stock Assessment Working Group; 2003

The monitoring program of demersal fish at inshore sites of the South Shetland Islands hascontinued in Potter Cove from 2000 to 2003, covering a continuous sampling period oftwenty years and in Harmony Cove, Nelson Island, in the austral summers from 2001 to2003. The decline in trammel net catches of fjord fishes of the species Notothenia rossii andGobionotothen gibberifrons in relation to the non commercially fished Notothenia coriiceps,which was already reported for the period 1983-1999, is still evident. At Potter Cove, highercatches of N. rossii were obtained from 1991 to 2000, but the actual levels of relativeabundance of this species and of G. gibberifrons are well below those found in the early1980s. At Harmony Cove, the relative abundance of N. rossii showed an increase in years2002-2003, whereas G. gibberifrons was absent in the catches. No recovery of the stocks ofthese two fish species was still observed, more than two decades after the end of thecommercial fishery. However, the increase observed in the catches of N. rossii in some yearssince 1997 might be indicative of events of higher recruitment, not yet confirmed by theoffshore scientific surveys carried out in the region. The results are consistent with dietinformation of the piscivorous Antarctic shag Phalacrocorax bransfieldensis in the SouthShetland-Antarctic Peninsula area obtained from the early 1990s.