Fish distribution and biomass in the Heard Island zone (Division 58.5.2)
Division 58.5.2 encompasses the southern part of the Kerguelen plateau, and contains Heard Island and the McDonald Islands, an Australian Territory around which a 200-mile EEZ has been declared. In order to assess the potential of this area for commercial fishing, and to obtain some preliminary data for its management, three random stratified surveys were conducted to investigate the distribution, abundance and biology of the most important species, covering a number of years and seasons. Five species were found to be abundant. There were two consistent areas of aggregation of Champsocephalus gunnari, but total abundance varied greatly between years. Channichthys rhinoceratus has a similar distribution, but abundance is lower and less variable with location and between surveys. Dissostichus eleginoides is widespread over those parts of the plateau where waters are more than 300 m deep, but is nowhere very abundant, although the total biomass is relatively high by virtue of the large area it occupies. There was one aggregation area of Lepidonotothen squamifrons on an outlying bank during two surveys, but this had disappeared by the third survey. Rays were widespread and moderately abundant in waters shallower than 300 m. From these results, it seems that a small fishery of a few hundred tonnes each for C. gunnari and D. eleginoides may be possible.