Observations on the by-catch of dolphins Stenella longirostris, Tursiops aduncus, Sousa chinensis and Delphinus delphis Tropicalis in the gill nets off Calicut coast, India

Species composition, length distribution seasonal variation in occurrence and sex ratio of 174 dolphins from Calicut coast were studied for the period 1976 to 1980. The incidence of dolphins in the gill nets were found to be more during the colder months of the year from October to February. Stenella longirostns contributed 52.9% of the dolphins landed followed by Tursiops adimcus which formed 32.7%. Delphinus delphis tropicalis and Sousa chinensis were the other two species that occurred in the net