Crab by-catch in the experimental toothfish pot fishery around South Georgia, 2000

Trials of a method of fishing for toothfish using pots were undertaken by FV Argos Georgia from March to May 2000. A significant bycatch of crabs was encountered. Paralomis spinosissima occurred in shallow water, generally shallower than 800m. P. anamerae, which has not been reported for this area previously, had an intermediate depth distribution from 400 – 800m. P. formosa was present in shallow waters but reached much higher catch levels (and, presumably, densities) between 800 and 1400m. There were some differences in catch rate5 between areas, with lowest catch rates being encountered between Shag Rocks and South Georgia, and highest for P. formosa in deep water north of South Georgia. Few crabs (3% of P. spinosissima and 10.5% of P. .formosa) were males above the legal size limit and could be retained. All other crabs were discarded. Mortality rates estimated from re-immersion experiments indicated that about 10% of apparently lively discarded crabs would die.