Observation on selectivity of fishing gears and ichthyofaunal diversity in the Paira River of Southern Bangladesh

Abstract

Paira River, a coastal water body of Patuakhali district having immense aquatic biota especially fishes. An attempt has been undertaken for a period of 7 months from March 2015 to September 2015 to estimate the fishing gears, their mesh size and ichthyofaunal diversity status in the Southern Bangladesh along with the globe. The study discovered total seven major types of fishing gears defined as gill nets (saine jal and current jal), lift nets (dharma jal), push net (thela jal and moiya jal), seine net (ber jal), fixed purse net (badha jal and gora jal), cast net (jhaki jal) and hook and line (chip barshi and chara barshi). A total of 57 species of fishes were identified belongs to 10 orders and 28 families of which Perciformes were of the highest occurrence (33.33%) order of the total fish population followed by 21.05%, 19.30%, 10.53%, 5.26%, and 2.51% for Cypriniformes, Siluriformes, Clupeiformes, Synbranchiformes and Beloniformes, respectively. Four orders viz., Cyprinodontiformes, Osteoglossiformes, Pleuronectiformes and Tetraodontiformes were found in the same percentage (1.75% for each) of the total number of fish species. Out of these 57 species about 8 species have to be found endangered and 3 to critically endangered in Bangladesh whereas in the globe total 4 species recorded as near threatened. Over fishing, use of restricted fishing gears and different forms of pollution are the most important factors for declining of fish diversity from the Paira River. For sustainability of these resources, an adequate knowledge of fishing gears, species composition, fish diversity and conservation status of available fish species must be understood.