ESTIMATED CATCH AND MORTALITY OF SEA-TURTLES FROM THE EAST-COAST OTTER-TRAWL-FISHERY OF QUEENSLAND, AUSTRALIA

Trawling for penaeid prawns has been suggested to have major effects o n the size of sea populations in Australia and overseas. The numbers o f turtles caught and killed in the Queensland East Coast Otter Trawl F ishery were estimated from a 2-year programme monitoring turtle captur es in this commercial prawn trawl fishery. A sample of about 50 commer cial fishers participated and reported an average catch rate of 0.068 turtles per day fished. Loggerhead Caretta caretta (50.4%), green Chel onia mydas (30.1%) and flatback Natator depressus (10.9%) turtles comp rised the main species caught. An estimated 5295 +/- 1231 turtles were caught annually by the Queensland East Coast Otter Trawl Fishery, whi ch has an annual fishing effort of 80,558 days. About 1.1% of captured turtles were reported dead when landed. This mortality rate is lower than those reported for other trawl fisheries because in the Queenslan d East Coast Otter Trawl Fishery tow durations are short (<80 min) whe re turtles are commonly caught. Potentially, if all comatose turtles a re assumed to die, the mortality rate of trawl caught turtles could be as high as 6.8%. However, the true mortality rate is probably somewhe re between 1.1% and 6.8% of turtles landed because some commercial fis hers resuscitate trawl-caught turtles.