FINE-SCALE MAPPING OF FISH DISTRIBUTION FROM COMMERCIAL CATCH AND EFFORT DATA USING MAXIMUM-ENTROPY TOMOGRAPHY

We present a technique for mapping the spatial distribution of fish us ing commercial catch and effort data. The relative fish density can be estimated at scales smaller than the length of the unit of effort, su ch as a tow, by using a Bayesian maximum entropy method. This can take advantage of the fact that the tows cross to give information about t he density in those areas. This is a novel application of a well-teste d technique that has been used in other fields such as astronomical im aging. Its utility and robustness is demonstrated both on simulated da ta and on real data from the trawl fishery on spawning hoki off the we st coast of the South Island of New Zealand.