Stock, Maximum Sustainable Yield, and Management Status of Tenualosa ilisha in Bangladesh Waters

Abstract

The gregarious hilsa, Tenualosa ilisha, is an anadromous fish predominantly a marine variety migrating from marine environment to estuarine and freshwater environment for spawning, nursing, and feeding purposes. It is the major catchment species particularly in Bangladesh, India, and Myanmar. Presently a major gap in understanding on stock size and maximum sustainable yield (MSY) of hilsa and their habitats ecology has created the new challenges for the researchers and policy makers to implement the science-based hilsa management. Thus, we critically reviewed population dynamics parameters of hilsa, i.e., migration pattern, growth, mortality, exploitation, standing stock status, and MSY to provide information for supporting a more operative hilsa fishery management particularly conservation techniques for sustenance of this fish in the region. T. ilisha migrated throughout the year in the coast and all the main rivers of Bangladesh. Their peak migrations showed in September to October and continuously occurred in every 2 months of intervals. Distribution of hilsa in Bangladesh indicated that remarkable juvenile hilsa starts migration from the February, whereas the migration of matured hilsa is not bounded to monsoon period only, but this fish also migrates for a short duration in the winter season. Exploitation status from 1995 to 2016 indicated that the fish is overexploited in the last decades that affect the MSY of this fishery. Thus, the review summarized the migration pattern, population parameters, stock size, maximum sustainable yield, and their current exploitation status that can be helpful for hilsa shad protection and conservation especially in Bangladesh waters.