PROPOSAL FOR AN EXTENSION TO THE MARK–RECAPTURE EXPERIMENT TO ESTIMATE TOOTHFISH POPULATION SIZE IN THE SOUTH OF SUBAREA 48.4

1. A three-year tagging study in the South of Subarea 48.4 was initiated in the 2008/09 fishing season with the aims of providing the data required for assessments of the population structure, size, movement and growth of both Dissostichus eleginoides and Dissostichus mawsoni in the South of 48.4; 2. In 2008/09 a total of 214 D. eleginoides and 192 D. mawsoni were tagged and released. Two tagged D. mawsoni were recaptured in the first season. 3. Macrourids and rajids dominated finfish bycatch with discard weights at 19% and 0.8% of toothfish catches, respectively. These rates are similar to those experienced in the North of 48.4. 196 Amblyraja georgiana and 1 Bathyraja eatonii were tagged and released and none were recaptured; 4. Almost half (47%) of sets were undertaken during daylight hours and no bird entanglements or mortalities were reported; 5. The UK proposes to continue the mark-recapture experiment in the South of Subarea 48.4 in 2009/10 with a combined catch limit of 75 tonnes for Dissostichus spp. 6. It is proposed that tagging effort is restricted to D. mawsoni which dominates catches in the South of 48.4.