Multi-specific effects of increasing T90 mesh size and amount in an Australian fish trawl

Increases in the size and amount of meshes turned 90° ('T90') an Australian fish-trawl codend were investigated to improve selection deepwater flathead Neoplatycephalus conatus reduce discards. The conventional comprised 94-mm mesh throughout with normal orientation (diamond-shaped) posterior half but T90 anterior ('half T90' codend). Two new codends had 105-mm section only T90') ('full T90'). Both larger-meshed caught fewer immature flathead, also lost some larger fish, especially full codend, which 80% more meshes. allowed discarded species escape, similarly affected other targets. Collected morphological data support a ~100 mm or ~94 maintain target sizes. However, irrespective changes meshes, owing comparable inter-specific sizes shapes, discard percentage this fishery will probably remain consistent at >75%, is than double global average for fish trawls. Future efforts should consider modifications changes.