~ 382 ~  International Journal of Fisheries and Aquatic Studies 2016; 4(2): 382-387  ISSN: 2347-5129 (ICV-Poland) Impact Value: 5.62  (GIF) Impact Factor: 0.352 IJFAS 2016; 4(2): 382-387 © 2016 IJFAS www.fisheriesjournal.com Received: 05-02-2016 Accepted: 08-03-2016 Md. Bokthier Rahman Department of Fisheries Technology, Faculty of Fisheries, Patuakhali Science and Technology University, Dumki, Patuakhali- 8602, Bangladesh. Md. Sazedul Hoque Department of Fisheries Technology, Faculty of Fisheries, Patuakhali Science and Technology University, Dumki, Patuakhali- 8602, Bangladesh Shihab Sharar Mukit Department of Fisheries Technology, Faculty of Fisheries, Patuakhali Science and Technology University, Dumki, Patuakhali- 8602, Bangladesh. Mehedi Azam Department of Aquaculture, Faculty of Fisheries, Patuakhali Science and Technology University, Dumki, Patuakhali- 8602, Bangladesh Manosh Mondal Department of Aquaculture, Faculty of Fisheries, Patuakhali Science and Technology University, Dumki, Patuakhali- 8602, Bangladesh Correspondence Md. Bokthier Rahman Department of Fisheries Technology, Faculty of Fisheries, Patuakhali Science and Technology University, Dumki, Patuakhali- 8602, Bangladesh. Gears specific Catch Per Unit Effort (CPUE) with special reference to declining causes of ichthyofauna in the Kajal River of Southern Bangladesh Md. Bokthier Rahman, Md. Sazedul Hoque, Shihab Sharar Mukit, Mehedi Azam, Manosh Mondal Abstract The Kajal River is a coastal water body, having vast aquatic biota which situated at Rangabali upazila under Southern district of Patuakhali in Bangladesh. Different types of fishing gears have been operated in the river to capture aquatic resources especially fishes which were investigated by employing participatory rural appraisal (PRA) such as focus groups (FGD), key informant interviews (KIA) with fisher’s community fishing in the river for a period of 8 months from March 2015 to October 2015. A total of fifteen (15) fishing gears under seven (7) major groups of net were identified. Estimated CPUE of various gears was found highest (5-8 kg) for Current jal and lowest (0.01-.06 kg) for Moia jal. In total, forty three (43) species were recorded belongs to eleven (11) orders, twenty four (24) families and thirty four (34) genera in the catches of different gears. Among the 43 species, 20, 13, 4 and 6 were to be found as available, less available, rare and very rare, respectively. A total of seven (7) vulnerable, two (2) endangered and two (2) critically endangered species were obtained out of 43 species. But these numbers are increasing day by day due to both natural and manmade causes. Therefore, necessary measures should be taken to conserve the species from near extinction. Keywords: Conservation, CPUE, Extinction, Fishing gears, Fisheries biodiversity, Mesh size, Kajal River. 1. Introduction Bangladesh, the world largest deltaic region, lies in the northeastern part of South Asia, is exceptionally endowed with a vast variety of flora and fauna due to its unique geophysical location (Nishat et al. 2002) [1] . The pride of Bangladesh is its rivers with one of the largest networks in the world which is the habitat of at least 265 freshwater fish species (Rahman 2005) [2] . Being a country of rivers and floodplain with a high potential of aquatic resources, fish plays a very important role in daily life of many people in Bangladesh. Fish alone donates 60% animal protein intake (DoF 2015) [3] which solves malnutrition related problem. Coastal fisheries are one of the major contributors to inland fish production in Bangladesh. Numbers of coastal water bodies are prominent in Southern region of which Kajal River is the most imperative, located at Rangabali upazila under Patuakhali district. A small piece of land rise from river beds in Rangabali upazila labeled as Char Kajal from which the river is characterized as Kajal River. The river has many distributaries which serve as the migration route of migratory species of fishes especially hilsa as well as the place of other important species. So fishing is a common practice in terms of livelihood and nutrition ingestion for fisher’s community around the coast of the river. Numbers of scientific based investigation has been held on various aspects of fishes on different water bodies [7-18, 20-22] throughout the country. But no attempt has yet been identified on fishing gears and fish folk diversity of Kajal River to make acquainted the existing fisheries resource with potential impacts and declining causes of fish species. Diverse stresses like natural calamities, excess harvesting, agricultural runoff, siltation and different restricted fishing gears have been operated on fishes in very detrimental ways which reach the fish under threat. Biodiversity and its conservation are treated as one of the major issues of enabling sustainable use of natural resources. Therefore, it is necessary to carry out scientific based work on available fishing gears including their mesh size, catch per unit effort (CPUE), fisheries biodiversity, conservation status of available