CCAMLR

Haul by haul Chilean and Argentinian data show that fishing forDissostichus eleginoides in 1994/95 took place in two major fishing grounds, West of Shag Rocks (Wshag) and North-West of South Georgia (NWSG). In March there was a high proportion of large females at Wshag (72%) but a nearly equal proportion of males and females at NWSG. It is suggested that a strong influx of small fish at Wshag in April reduced the mean length in the catch and increased CPUE (numbers of fish per hook), although sex ratio remained biassed in favour of females. Similar changes in mean length and CPUE were not seen at NWSG, although the sex ratio did change in favour of males (60% male by early May). The changes at Wshag are hypothesised to be the result of a prespawning migration of sub-adults, especially males, from shallow waters to deeper spawning grounds just prior to spawning in June-July

Data on 6 juvenile fish surveys within South Georgia Subarea have been analysed in the paper. There has been revealed that the most abundant species in the catches by juvenile fish trawl were Champsocephalus gunnari and Lepidonotothen larseni and those the most varions were the representatives or Nototheniidse family (10 species), Myctophidae family (7 species) and Bathydraconidae family (5 species;). Data on size-composition of most abundant species taken with a midwater trawl, as well as on their size-composition and distribution in relation to space and depth have been given.

A randomised cluster design was used successfully to sample otoliths from targetted individuals taken by individual longlines in the fishery for Dissostichus eleginoides. The line was divided into constituent baskets of line; we used the line as the sampling frame, and baskets as the primary sampling units. The design allows representative samples to be taken while a line is being hauled; it offers the potential of little disruption to commercial activities and reductions in observer effort needed to achieve known levels of confidence.

A shore-based design used to sample sports fisheries was adapted to sample otoliths from targetted individuals caught in the artisanal longline fishery for Dissostichus eleginoides off northern Chile. Observers were stationed dockside and at a processing factory. A 14-day sampling frame was used, divided into primary sampling units of days/area and secondary sampling units of three- and eight-hour periods. Compared to shipboard sampling, the design allowed more flexibility in allocation of observer effort and cut time wasted during poor fishing or travel to fishing grounds. However, data on catch date, location, and depth cannot be independently verified, nor data taken on by-catch or incidental mortality of higher predators.