CCAMLR

Longline fishing for Patagonian toothfish Dissostichus eleginoides in the South African Exclusive Economic Zone around the Prince Edward Islands commenced in 1996. This paper summarises seabird bycatch during the year July 1997-June 1998. Data on seabird bycatches were obtained from fishery observers aboard all 11 sanctioned fishing trips, representing a fishing effort of 4.3 million hooks. This is 13% more than the number of hooks reported set in 1996-97, but total effort probably declined during 1997-98 as a result of a decrease in the number of unsanctioned vessels operating in the area. Observers reported 498 birds of five species killed. White-chinned Petrels Procellaria aequinoctialis predominated (96%), followed by giant petrels Macronectes spp. (3%), with Yellow-nosed Mollymawks Thalassarche chlororhynchos and crested penguins Eudyptes spp. each contributing Most birds were killed during setting. There was considerable variance between vessels (range among trips 0.000 to 0.456 birds per 1 000 hooks), with

Studies on DNA microsatellites and a tagging programme both provide information on the degree of interchange of Dissostichus eleginoides (Patagonian Toothfish) between two sites 40 nautical miles apart near Macquarie Island. Five DNA microsatellite loci were identified that showed polymorphism levels appropriate for population structure analysis, and two of these gave results that suggest samples from the two sites are not homogeneous at the 5% probability level. While the other three loci did not demonstrate significant spatial heterogeneity, combined results across all five loci again indicated heterogeneity at the 5% probability level. Results from tagging experiments support the inference from the genetic analyses that interchange of fish between the two sites is very low. Of 469 recaptures at both sites combined, only one fish had moved between sites. As the DNA analysis has so far only been performed on small numbers of fish and loci these results must be regarded as preliminary, but if confirmed by further study the implication of very localised stocks of D. eleginoides will have a great effect on the management of commercial fisheries for this species.