Mixed-species yield-per-recruit simulations of the effect of seasonal closure on a central Queensland coastal prawn trawling ground

An assessment of the effect of seasonal closure on the central Queensland coastal prawn trawling grounds was carried out by mixed-species yield-per-recruit simulations of the fishery based on parameters determined from field studies and analysis of logbook data. Under a conventional scenario of constant fishing mortality, simulations suggest little positive effect on yield to be achieved from closures of up to 15 wk in duration. Economic gain would have to be made via reduced costs during the closure, rather than through increased value of the postclosure yield. Logbook data clearly showed that the fishery underwent a heavy pulse of effort, immediately after the fishing season opened. Nonlocal boats had entered the fishery to take advantage of the prawns available. Using this more realistic regime of fishing mortality, simulations suggest a significant increase in yield and value of catch. The increase was caused by boosted exploitation rates of the stocks and was determined by the magnitude of the effort...