Avoidance of incidental mortality of seabirds and the implementation of Conservation Measure 169/XVII in Statistical Subarea 88.1 in the 1998/99 season

New Zealand conducted Longline weighting trials during the 1998/99 fishery for Dissostichus spp. in Sub-area 88.1. Daylight setting was allowed south of 65°S in Sub-area 88.1 under special provisions in Conservation Measure 169/XVII. The provisions included strictly applied line-weighting regimes and rigorous monitoring of line sink rates.
In the trials, two autoline vessels set weighted longlines in Statistical Sub-area 88.1 between 30th December 1998 and 27th February 1999. Time depth recorders were used to record the actual sink rate achieved on 30% of all sets. For all sets combined the average sink rate achieved was greater than the minimum required standard of 0.3 m/sec (mean = 0.37 m/sec, 1 s.d. = 0.06, n = 74). Observer coverage was 31% of all hooks hauled and 100% of all sets during the trials. During the trials, zero seabird mortalities were recorded. The need for further line-weighting trials and the development of new line-weighting technologies is recommended.