CCAMLR

It has been suggested a method of GY-model adjustment to the additional data of observations represented as abundance indices. Catch per effort values or results of inventory surveys can serve as such indices. Adjustment basic concept is a selection of those GY-models from realization sets a certain function of which runs through the set of points defined by confidence intervals of abundance index estimates. It has been shown as an example of D.eleginoides from Subarea 48.3 that GY-model adjustment to the catch per effort values should give estimates of potential yield (2500 tons), essentially differing from those obtained by a routine model usage (3500 tons).

In February-March 1999, a Russian fishing vessel "Zakhar Sorokin" carried out fishery for Champsocephalus gunnari in CCAMLR subarea 48.3. During the processing of catches taken in the area of the northwestern slope, two species of parasites were revealed: copepod Eubrachiella antarctica and leech Trulliobdella capitis Brinkman, 1948. Statistical data collected during examination of more than 3.000 specimens of icefish has shown that the average infestation of fish with copepods constituted 24.4% and with leeches - 18.5 %.

From 16 Fenruary to 10 March, 1999, a Russian large capacity trawler "Zakhar Sorokin" carried out fishery for icefish Gunnari in CCAMLR subarea 48.3. During the cruise, 88 hauls were done and 264,921 t of icefish were caught. 86% of catch were taken from 28 February to 3 March on the nothwestern slope of the South Georgia Island, where icefish fed actively on Antarctic krill and, therefore, formed dense commercial concentrations. In this period, catches constituted 3,4 t per trawling hour and 57 t per day of fishing. Icefish 27-33 cm long were the basis of catches. Total catch of other fish species constituted 9,171 t.
Due to opinion of the captain of a Russian vessel and Russian scientists, having large experience in fisheries and research in this area, the results of the cruise have proved a complexity of fishery for this species but are not an evidence of bad status of Champsocephalus gunnari stock in the subarea 48.3

To examine consistency between laboratories in age estimation of Patagonian toothfish, otoliths were taken from 100 fish caught in the South Atlantic, and transverse sections prepared by baking, then grinding from the anterior and posterior sides of the otolith. Ages were estimated from the otoliths by one reader from the Center for Quantitative Fisheries Ecology at Old Dominion University and one reader from the National Institute of Water and Atmospheric Research, without auxiliary information: the readers generally read the sections similarly, with 84.7% of the estimates falling within two years or less of each other. Variation in estimates between readers did not increase markedly with age; however. the CQFE reader tended to give higher age estimates than the NIWA reader consistently over the full age range, indicating differences in the criteria used to interpret the first few years of age, possibly in identification of the first annulus.

The need to protect young fish and spawning aggregations in fisheries generally, and specifically in the C. gunnari fishery in Subarea 48.3, is reviewed. Mechanisms available to achieve these objectives are discussed, including the measures put in place by CCAMLR to date. These measures are re-examined in the light of new information, and a strategy for the future protection of young fish and spawning aggregations of C. gunnari in Subarea 48.3 is proposed.