Population structure and length-weight relationship of Epinephelus diacanthus from Ponnani, South India

Groupers in addition to their importance to local economies, are apex predators thought to play important roles in ecosystem function. Ponnani in South West coast of India, has been a good landing centre for a particular species of grouper, Epinephelus diacanthus. However, of late the mean length of individual landed has shown a drastic reduction. Most of the fishes caught are either juveniles or sub adults. This paper elucidates the population structure of E. diacanthus through length-weight relationship analysis of the fish landings. Results emerging from the present study indicate the dismal condition of the Spinycheek grouper stock along the South Western coast of India. The study also suggests that unless stringent management measures are not implemented to restrict overexploitation of this species, it is likely that the species that has been categorized a ‘Near Threatened’ under IUCN Red list would soon become ‘Endangered’. Being an apex predator in the demersal food web, depletion of stock of E. diacanthus, would alter the ecological heath.