Fishery and ecology of the spiny lobster Panulirus homarus (Linnaeus, 1758) at Khadiyapatanam in the southwest coast of India

Commercial exploitation of palinurid lobsters has been on the increase due to high demand and lucrative price for live lobsters in the international market. The spiny lobster Panulirus homarus caught generally by traps and bottom-set gillnets support significant commercial catches along the southern Indian coast. Fishery along the southwest coast is seasonal, extending from September to March and peak landings are during October to December. The catch gradually declines from January and the landing is negligible in April and May. The paper presents results of a field study carried out on the ecology of the lobster fishing ground at Khadiyapatanam, on the southwest coast of India. Hydrographical parameters were used to correlate the lobster catch from the coastal fishing grounds during the fishing (October-November) and the non-fishing season (April-May) for which lobster catch and the entangled associated fauna and flora from 8 bottom-set-gillnets operated at different depth zones were monitored. Mean catch in the bottom-set- gillnet varied from 1.6 to 0.68 kg/net/day during October-January and 0.1 kg/net/day during April-May. Negative correlation between bottom sea water temperature and the catch of P. homarus was observed. The environmental and ecological conditions, widespread beds of the brown mussel Perna indica are likely to be impacting the abundance of P. homarus at Khadiyapatanam fishing ground. The major groups of organisms in the fishing ground were echinoderms, fishes, sponges, crustaceans and molluscs. The paper discusses the probable influence of environmental and ecological factors that impact the distribution and fishery of P. homarus in the fishing grounds of Khadiyapatanam