Rajid by-catch in the longline fishery for toothfish in Subarea 48.3

In response to concern about rajid bycatch in CCAMLR finfish fisheries, we conducted a preliminary analysis of data collected by UK scientific observers on vessels fishing toothfish in Subarea 48.3 from April to July 1999. The overall average catch rate of rays was 0.7/thousand hooks, compared with 34.7/thousand hooks for toothfish and 2.2/thousand hooks for grenadier species. Generalised linear models demonstrated that there are significant differences between the catch rates of rays for different vessels, areas, and depths in Subarea 48.3. Some vessels, fishing on the northern shelf edges of both Shag Rocks and South Georgia, achieved average catch rates of over 1 ray/thousand hooks, and 20-30 rays/ thousand toothfish. Catch rates were lowest to the south and east of South Georgia. The two species most frequently found on hooks were R. georgiana and B. murrayi. R. georgiana was found in all areas, B. murrayi was not found in this study to the east or south of South Georgia. Modal length of R. georgiana caught was 65-69cm for males and 80-84cm for females, for B. murrayi was 65-69cm and 70-74cm for males and females respectively.