Confirmed Sighting of a Spawning Aggregation of the Brown-marbled Grouper, Epinephelus fuscoguttatus, in Kenya

Abstract

The occurrence of spawning aggregations at fixed sites and times is well documented for several species of reef fish. These aggregations are known to attract fishers and such species may therefore be vulnerable to overfishing. This is particularly true in the case of groupers which have intrinsically vulnerable life history traits. The brown-marbled grouper, Epinephelus fuscoguttatus, distributed throughout the Indo-Pacific region and classified by IUCN as Near Threatened, is reported to form spawning aggregations but little is known about its spawning behaviour; in the Western Indian Ocean this has only been reported for the Seychelles. This study confirmed spawning aggregation behaviour in E. fuscoguttatus in Kenya based on underwater observations and fishers’ knowledge of the phenomenon. We showed that E. fuscoguttatus forms short aggregations for ~5 days linked to the new moon for a 3-4 month period during the northeast monsoon (austral summer).  The numbers of aggregating fish appear to be low, however, and the species is currently not managed in Kenya. Considering the fact that only small areas of the Kenyan coastline are under total protection (8.6% of the country’s coral reefs), these factors suggest that there is an urgent need for additional management of E. fuscoguttatus if it is to survive in Kenya.