Epinephelus Genus Groupers Population Structure and Length-Weight Relationships off Kenyan South Coast Indian Ocean Marine Waters

Groupers are apex predatory fishes playing important local economic roles and ecosystem functions worldwide. The Kenyan coast Indian Ocean waters have been a good landing centre for nearly 30% of the already identified 98 Epinephelus genus species groupers. However, of late, their natural populations have greatly decreased with the landed individuals mean length and weights showing drastic reductions. Most are therefore caught when either juveniles or sub adults. Information data is therefore needed to avert this alarming decline and initiate conservation measures for these prized premium fishes. This study elucidates the Epinephelus genus groupers population structures and length-weight relationship analyses for these highly sought fishes from Kenyan inshore marine waters. The study results indicated varying significant conditions (p<0.001) for these species having Length-Weight Relationship (LWR) regression coefficients (R2) that appeared to be stronger (R2>0.6000) for 23 species. Despite this apparently strong fit, Analysis of Covariance (ANCOVA) revealed no significant differences between (a) intercept and (b) slopes of the species regression lines (p = 0.5552). R2 analyses also showed consistent non isometric patterns in the plotted power curved data suggesting that unless stringent management measures are implemented to restrict over-exploitation, it is likely that the species currently categorized as ‘Near Threatened’ under the International Union for Conservation of Nature (IUCN) Red list would soon become ‘Endangered’ while those ‘Endangered’ extinct. This can greatly alter the ecosystems’ ecological health as they are apex predators in the demersal food web and their stock depletions would result in the alteration of the ecosystem.