ANALYSIS OF VESSEL MOVEMENTS AND STRATEGIES USING COMMERCIAL CATCH AND EFFORT DATA FROM THE NEW-ZEALAND HOKI FISHERY

Standardized catch rates from a multiplicative model of commercial cat ch per unit effort data have been examined to investigate vessel movem ents and strategies. A linear model was fitted to log-transformed comm ercial catch per unit effort data in the spawning hoki trawl fishery o ff the west coast of the South Island of New Zealand. The residuals fr om this model were examined; catch rates from tows done by different v essels at different times of day are standardized and, therefore, comp arable. There is evidence that vessels make decisions about where to f ish based on both their own recent catch history and on observations a bout the location and aggregation of other vessels. There is no eviden ce that there is enough information transfer for vessels to make decis ions on the basis of catch rates of the other vessels in the fleet.