SynopsisRelationships between quantitative measures of habitat type and the biomass of Chaetodon, Scarus and Parupeneus species were investigated across 35 reef sites in the Inner Seychelles Group. Multiple regression was used to determine the proportion of variance in biomass between sites which could be explained by depth, exposure, vertical relief, topographic complexity, live coral cover, coral rubble cover, rock cover, sand cover, underlying carbonate substrate, underlying sand substrate, underlying rock substrate and an index of fishing intensity. A significant proportion of the variance in biomass was explained by habitat variables and the index of fishing intensity for 7 of 12 Chaetodon species (23-52% of variance explained), 3 of 6 Parupeneus species (33-40%), and 10 of 13 Scarus species (1446%). Within genera, different groups of habitat variables explained the variance in biomass for different species and, of the variables studied, only the proportion of underlying sand substrate failed to explain a significant proportion of the variance in biomass for any species. Quantitative relationships between the biomass of Chaetodon and habitat were often in accordance with those suggested by previous studies of their ecology, life-history and distribution at other Indo-Pacific locations. However, the habitat associations of the Parupeneus and some Scarus species have not been studied at other locations and clearly warrant further investigation. It was concluded that habitat was an important determinant of the distribution of many Seychelles reef fishes, but that the habitat variables examined were rarely the most important determinant of biomass. However, the inclusion of a procedure to collect habitat data provided a useful means by which to reduce the unexplained variance associated with visual census biomass estimates and therefore improves the possibility of elucidating the effects of other factors on the biomass of Seychelles reef fishes.

The Western Indian Ocean represents ca. 8% of the world's oceans but generates only 4% of the global industrial catch. This region is also home to a great proportion of the world's population, living in developing countries with a high dependence on marine resources. Trends in the declared landings of marine resources from the Western Indian Ocean suggest that this ocean may be approaching its maximum harvest potential of ca. 4 Mt per annum, but underreported artisanal catches complicate more-detailed analyses. There is a growing demand for 'new resources' to make up for declining stocks, while several large fluctuations are linked to changes in market demand and over exploitation. Artisanal fisheries in the region are highly diversified. Preliminary results are presented of a project that evaluates the conservation status and sustainable management practices in 168 different fishery types. It is concluded that the majority of the region's artisanal fisheries are not adequately supported by scientific information and that management strategies need to be improved if the enormous development challenges of East African countries are to be met.