Information on the status of fjord fish (Notothenia rossii, Gobionotothen gibberifrons and Notothenia coriiceps) in the lower South Shetland Islands derived from a long-term monitoring program (1983?2006) at Potter Cove.

BARRERA ORO, ESTEBAN RODRIGO; MARSCHOFF, ENRIQUE

Hobart, Australia

Otro; Working Group on Fish Stock Assessment (WG-FSA); 2006

Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR)

WG-FSA-06/25 The long-term monitoring program of demersal fish at inshore sites of the South Shetland Islands has continued at Potter Cove from 2000 to 2006, covering a continuous sampling period of 24 years, and at Harmony Cove, Nelson Island, in the austral summers from 2001 to 2003. The decline in trammel net catches of fjord fish of the species Notothenia rossii and Gobionotothen gibberifrons in relation to the non-commercially fished N. coriiceps, which was previously reported for the period 1983?1999, is still evident. At Potter Cove, despite an overall increasing trend of N. rossii catches from 1991 to 2006, the actual levels are half of those found in the early 1980s, while those of G. gibberifrons further declined and remain close to zero. At Harmony Cove, the relative abundance of N. rossii showed an increase in 2002 and 2003, whereas G. gibberifrons was absent in the catches. These trends are consistent with those observed in scientific cruises on the offshore populations in a similar period. Commercial fishing off the South Shetland Islands in the late 1970s is the most likely explanation for the decrease in recruitment to the inshore sub-populations of N. rossii and G. gibberifrons. No recovery of the stocks of these two fish species was observed, even more than two decades after the end of the commercial fishery. Both, present results of inshore monitoring and those of the offshore cruises since 1998 show that the populations of N. rossii and G. gibberifrons in the South Shetland Islands region cannot, at present, sustain a commercial fishery.