Fish Diversity in the Southern Coastal Waters of Bangladesh: Present Status, Threats and Conservation Perspectives

Despite the enormous anthropogenic and environmental hazards affecting wild fisheries resources, southern coastal waters are still considered one of the aquatic biodiversity hotspots in Bangladesh. Therefore, the present study was conducted to make a complete account of fishes and to assess their condition and conservation status in the rivers spread across four southern coastal districts of Bangladesh. During the study period from January to December 2014, a total of 98 species of fish were recorded belonging to 81 genera, 48 families and 13 orders. Perciforms were recorded as the most diverse fish group in terms of both number and individuals of species observed. Of the 98 species, 26.53% were listed as Locally Threatened in Bangladesh, including 11.22% species listed as Vulnerable, 10.20% as Endangered and 5.10% as Critically Endangered. Four population indices viz, Shannon–Wiener index (H), Simpson’s dominance index (D), Simpson’s index of diversity (1-D) and Margalef’s index (d) were applied to demonstrate the species diversity, richness and evenness of fish in sampling areas and their overall values were 3.54-3.70, 0.04-0.05, 0.95-0.96 and 7.48-8.67, respectively. To sustain the prospect of fisheries biodiversity in the southern coastal areas of Bangladesh, management and conservation strategies like restocking economically important fish species, establishing and maintaining fish sanctuaries, banning indiscriminate fishing and destructive fishing gears, identification and protection of the breeding and nursery grounds should be taken into consideration with utmost priority.