Estimates of bird by-catch by IUU vessels in Subarea 48.3,
1998–2001

Estimates of bird catches by IUU fishing made using the new method presented by Agnew and Kirkwood last year (WG-FSA-02/4 & 5) are updated to take account of the comments of the working group. Last year we suggested that the Isabel data from 1997 were rather atypical of bird catch rates in the illegal fishery, and that these were more likely to be similar to the bird catch rates made by other vessels in 1997. Including the Isabel data and weighting the bootstrap estimates of bird catch rate by the number of hooks observed leads to revised estimates of total catch in 1999, 2000 and 2001 of 1115, 4898 and 1236 birds respectively. The relevant rates per 1000 hooks for this bootstrapping option, which should be used by WG-FSA/IMAF in future estimates of bird bycatch rates are:
a. Summer: Median: 0.741 birds/1000 hooks; 95% confidence limits – lower: 0.39, upper: 11.641
b. Winter: Median: 0.0 birds/1000 hooks; 95% confidence limits – lower: 0.0, upper: 0.99.