Catch composition and sustainability of the marine aquarium fishery in Kenya

Abstract

Management of the marine aquarium fishery in Kenya and most of the Western Indian Ocean (WIO) region is challenged by a poor understanding of the status and impacts of the fishery on stocks due to lack of long-term species-specific data sets. In this study, we analyzed commercial catch and effort data over a six-year period (2006–2011), provided by a major exporter, constituting over 70% of the total national catch, in order to assess spatial and temporal variations in catch composition for 11 fishing grounds in coastal Kenya. In addition, a semi-quantitative risk assessment based on Productivity Susceptibility Analysis (PSA) was applied on 102 target species to identify species at risk of overexploitation by the fishery. Between 2006 and 2011, approximately 1.54 million aquarium fish were collected constituting 220 species in 36 fish families. The catch was numerically dominated by Labridae (32%), Pomacentridae (14%), Serranidae (9%), Blenniidae (9%), Scorpaenidae (7%), Pomacanthidae (5%) and Acanthuridae (5%). Thirty-two species made up 80% of the catch with the cleaner wrasse, Labroides dimidiatus and the anthias, Pseudanthias squamipinnis being the most collected with a relative abundance of 11% and 7%, respectively. Multivariate nMDS analysis of the catch composition grouped the fishing grounds into three clusters and mostly influenced by the mode of fishing (snorkeling or SCUBA diving). Detrended Correspondence Analysis (DCA) further showed an association of some species to specific fishing grounds. The PSA showed that 91 species (90%) fell in the high productivity and low susceptibility risk categories placing them at a relatively low risk of depletion by the fishery. However, four species: Pomacanthus maculosus, Pomacanthus chrysurus, Amphiprion allardi, and Amphiprion akallopisos were ranked at high risk, and seven species at moderate risk of overexploitation. The findings highlight the need for closer monitoring of the aquarium fishery in Kenya and the WIO; and institution of precautionary management measures such as area closures and species restrictions to ensure sustainability in the fishery.