MEPS 452:159-170 (2012)  -  DOI: https://doi.org/10.3354/meps09665

ABSTRACT: The tropical sea cucumber (Aspidochirotida) fishery for the lucrative Asian dried-seafood trade is a multi-species fishery with little ecological knowledge. To improve ecological understanding of the targeted species, the reefs of Mayotte, Western Indian Ocean, were surveyed to document the distribution, species assemblage and habitat utilization of commercial sea cucumbers. This is one of the few reef areas in the region protected from fishing, thus providing an important and unique opportunity to investigate sea cucumber ecology. Twenty-two species were observed. The medium-value Bohadschia atra and the high-value Holothuria nobilis were the most abundant species. Species distribution varied but the density was generally similar across areas and habitats. Multivariate analysis (ANOSIM) indicated that the community was similar between surveyed areas and reef habitats. Diversity was lower in one of the surveyed areas and in the ocean-facing barrier reef habitat. Habitat complexity was not a significant driver of diversity or abundance. A principal component analysis showed that the 6 most common species (B. atra, Holothuria atra, H. fuscopunctata, H. nobilis and Thelenota ananas) were associated with different substrate types. Clustering these species according to substrate variables indicated both habitat utilization overlap and segregation among species, valuable information for spatial planning of fisheries management and conservation. Although unique species were observed in some areas, the present study shows that, at a large spatial scale, the unfished reefs in Mayotte consist of similar commercial sea cucumber communities, an important baseline finding.

KEY WORDS: Coral reefs · Bêche-de-mer · Trepang · Habitat · Ecosystem-based management · Fisheries management · Tropical seascape