The effect of trawling and subsequent handling on the survival rates of the by-catch of prawn trawlers in Moreton Bay, Australia

Abstract The fate of by-catch discarded by the Moreton Bay prawn trawl fishery was studied between September 1983 and March 1986. The composition and biomass of the by-catch were ascertained and the effect of trawling and handling on its survival was measured. The by-catch was made up of 52% crustaceans, 15% elasmobranchs, 8% bony fish, 18% echinoderms, 3% cephalopods and 4% debris by weight. Trawl hauls lasted about 60 min. and the catch was sorted in about 20 min. About 85% of the Crustacea and about 20% of the bony fish were still alive 8 h after sorting.