Declining catch rates of reef fish in Aldabra's marine protected area

Abstract

1. Fish landings from a small-scale subsistence fishery at Aldabra, Seychelles, were monitored from late 1995 to early 2007 to describe the predominant species caught, catch per unit effort (CPUE) and patterns in yield over time. 2. During this period a total of 19.5 tons of piscivores were caught, varying between 0.99 and 2.46 tons per annum. Effort data allowing for estimation of CPUE were available for 259 fishing trips and from 1998 onwards. 3. Over the study period, and in order of importance, Lutjanus bohar, Variola louti, Lethrinus nebulosus, Epinephelus multinotatus and Epinephelus polyphekadion made up over 80% of the total catch in terms of biomass. Using a general linear model, including fishing location and season as predictor variables, it was shown that CPUE declined significantly over the study period. Annual CPUE varied between 3.0 and 5.1 kg h -1 per person. 4. Throughout the period fishing pressure was low, and largely limited to the subsistence fishery. It is argued that changing catch rates are likely to have been independent of direct anthropogenic influences but a result of reef degradation following the 1998 bleaching event.