ASFB Home > The effects of spatial and temporal factors on the abundance of seven key finfish species along south-western Australia.

Evaluation of the impact of spatial effort quota and area closures on the stock of a prized species, Lutjanid sebae, in the Pilbara fishery, Western Australia.

Peter Stephenson and Norm Hall

Department Of Fisheries Western Australia, NORTH BEACH, AUSTRALIA

THEME: ASFB

The effectiveness of an area closure and spatially based effort quotas on the stocks of red emperor (Lutjanus sebae) in the Pilbara Fishery, on the north-west shelf of Western Australia, was assessed using an age and sex structured spatial model. The inputs to the model included Tiawanese trawl catches from 1972 to 1990, the domestic trawl, trap, line, and recreational catches from 1985 to 2001, biological parameters, age structure data, and trawl catch rates from 1993 to 2001. Various scenarios involving, different biological parameters, and estimates of efficiency were used to determine probabilities of achieving the target, 40% of virgin biomass in 2010, for different future values of trawl and trap effort. The likely future catches were determined for the current area closure and also if there had been no closed area.