ESTIMATION OF THE SIZE OF A CORAL-REEF FISH POPULATION

The present study monitored a fish population before and after fishing within a marked area. Visual census counts along transects were used to estimate fish abundance inside and around the fishing area. The emp eror Lethrinus borbonicus made up 64% of fish in terms of numbers and 44% of the catch in terms of weight. As fishing progressed, the catch per unit effort (CPUE) of L. borbonicus declined. Visual census counts of L. borbonicus were lower after fishing both inside and outside the fishing area. Linear models were used to calibrate CPUE and visual ce nsus data as indices of abundance to obtain 2 independent estimates of population size, which were found to be similar. These estimates furt her converged if the models included an estimate of the immigration ra te into the fished population. The present study demonstrated that dep letion experiments provide valuable information on coral reef fish pop ulations, particularly for fisheries.