Assessment of the fishery, growth, mortality and exploitation of Indo-Pacific tarpon, Megalops cyprinoides (Broussonet, 1782) from a microtidal tropical estuary, South West coast of India

Megalops cyprinoides is distributed in tropical and subtropical waters of Indo-Pacific Ocean. The population of the species have declined in recent years due to the over exploitation for commercial fisheries, habitat loss and alteration of freshwater flow from rivers and the species listed as Data Deficient (DD) in the IUCN red list. The present study reports on the fishery, length-weight relationships, growth, mortality and exploitation of M. cyprinoides from Kodungallur-Azhikode estuary, South West coast of India. Monthly catches of the species from the estuary varied from 135kg to 710kg. The length-weight relationship of the population was described by the equation: BW= 0.006TL^2.98 (r= 0.99). The growth parameters, asymptotic length (L∞) and growth coefficients (K) were 394.8mm and 0.87 year^-1 respectively. The potential longevity (tmax) and the observed length at first capture (Lc) were estimated to be 3.44 years and 227.90mm respectively. Fishing mortality rate (F= 1.24 year^-1) of M. cyprinoides was higher than the natural mortality rate (M = 0.82 year^-1) and the present exploitation level (E=0.60) is 80% of the predicted maximum exploitation (Emax=0.75), which indicates that the stock is over exploited under current level of harvest. Therefore, the present investigation suggests reducing the fishing pressure for M. cyprinoides along the Indian coastal water that will be useful for their sustainable fisheries management.