Nature and Science 2018;16(1) http://www.sciencepub.net/nature Operational System and Catch Composition of Charberjal (Fixed Net) in Tetulia River and its Impact on Fisheries Biodiversity in the Coastal Region of Bangladesh Md. Moazzem Hossain1, Masum Billah2, Md. Belal Hossen3, Md. Hafijur Rahman4 1Department of Fisheries Management, Patuakhali Science and Technology University, Dumki, Patuakhali-8602, Bangladesh 2Department of Aquaculture, Patuakhali Science and Technology University, Dumki, Patuakhali-8602, Bangladesh 3Department of Fisheries Biology and Genetics, Patuakhali Science and Technology University, Dumki, Patuakhali- 8602, Bangladesh 4Department of Fisheries Management, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh Email: [email protected] Abstract: An investigation was carried out to acquire the knowledge regarding charberjal operation system in Tetulia River and its impact on fisheries biodiversity in the coastal region of Bangladesh over a period of 6 months between July and December 2016. Combination of questionnaire interview, focus group discussions and crosscheck interviews were accomplished with key informants during data collection. Charberjal is operated in the shoreline of rivers, submerged chars and inundated agriculture land including tiny canals all over the coastal region of Bangladesh. A total of 80 species including finfish, freshwater prawn, crabs and mollusk was recorded under 22 families including 38 SIS and 26 threatened species during the study period. The recorded species was 60 finfish, 14 prawn, 4 mollusk and 2 crabs. Among the finfish rui, bata, mullet, khorsula and poa were the dominant species while aire, boal, bacha, ramsosh and tengra were the foremost species among catfish. Moreover, Macrobrachium rosenbargii was the most prevailing species among fresh water prawn while bele, phasa, puti, shol, dimua chingri and SIS were the most leading species among others. All types and all size of fish, prawn, mollusk and crustaceans and their larvae are trapped by this net during operation due to use small mesh size net and the trapped fishes die just after drying up of the shore and mixed with soil. As a result, huge number of commercially important fish larvae, eggs and fish fry are accidentally destroyed by charberjal operation system in the coastal region of Bangladesh. Due to lack of knowledge and indiscernible competition among the fishermen for fishing, they use this type of illegal and destroying fishing net for fishing which decline the fisheries biodiversity in the coastal region of Bangladesh. Charberjal is very harmful and has severe impact to destroy fisheries biodiversity including threatened species in the coastal region as well as all over the country. [Md. Moazzem Hossain, Masum Billah, Md. Belal Hossen, Md. Hafijur Rahman. Operational System and Catch Composition of Charberjal (Fixed Net) in Tetulia River and its Impact on Fisheries Biodiversity in the Coastal Region of Bangladesh. Nat Sci 2018;16(1):52-61]. ISSN 1545-0740 (print); ISSN 2375-7167 (online). http://www.sciencepub.net/nature. 7. doi:10.7537/marsnsj160118.07. Keywords: Charberjal operation system; coastal region; biodiversity; catch composition 1. Introduction about 3.65% to the GDP and 23.81% to the agriculture Bangladesh has the third biggest aquatic fish bio- while 18.2 million people directly and indirectly diversity in Asia after China and India with about 800 involved in this sector which is about 11% of total species in fresh, brackish and marine waters (Hussain population of Bangladesh (DOF, 2016). The total fish and Mazid, 2001). The country’s tropical climate, production was calculated at 36.84 lack metric tons of alluvial soils, productive waters and vast flood plains which 83.72% came from inland water and 16.28% are highly favorable to inland fisheries and from marine water in 2014-2015 (DOF, 2016). This aquaculture and Bangladesh ranks first (467 kg/km2) sector is influential for socio-economic development, in the world in open water fish production (Ahmed et nutrition supplementation, employment creation, al., 1997). It is one of the most compactly populated poverty alleviation and foreign exchange earning of countries in the world covering an area of 147500 Bangladesh (Hasan et al., 2011). Coastal region of square kilometer with a population of 164 million Bangladesh is reputation as valuable natural aquatic (Ahmed et al., 2012). It is called a land of rivers as it ecosystem due to the presence of appropriate natural has about 700 rivers including tributaries with the total feeding, spawning and nursery grounds for many length is about 24,140 km (DOF, 2015). Fisheries commercially important fish species (Mahmood et al., sector signifies one of the most creative and dynamic 1978; Hanif et al., 2015). Tetulia is one of the most sectors in Bangladesh and it contributes about 60% important coastal river with huge fishery resources of animal protein to the daily diets of the population, the southern part of Bangladesh originated from the 52 Nature and Science 2018;16(1) http://www.sciencepub.net/nature Meghna River from south-east part of Barisal district system, catch composition and its impact on fisheries and then flows down over three important coastal biodiversity and make some recommendations for the districts like Barisal, Bhola and Patualkahli through sustainable fisheries management in the coastal region ten upazilas namely Mehendijong, Muladi, Bauphal, of Bangladesh. Dashmina, Galachipa, Rangabali, Bhola Sadar, Borhanuddin, Lalmohan and Charfasion and then falls 2. Materials and Methods to the Bay of Bengal while it connected to numerous 2.1 Study area local rivers, canals and inundated agriculture lands. The study was undertaken in Tetulia River at Most of the agriculture lands of Barisal and Pirojpur Dashmina upazila under Patuakhali district located districts and some parts of Jhalokati, Patuakhali, between latitude 22°14´ to 22°20´ north and longitude Shariatpur and Madaripur districts are inundated for 6- 90°32´ to 90°40´ east in the coastal region of 8 months (Rasid, 1981; BARCIR, 2004) from April to Bangladesh (Figure 1). November, contain 5-7 feet water and make huge area The selected river is represented the common of water resources when growth rate fish especially picture of the charberjal operation and fishing system puti, shing, magur, koi, taki, shol, tengra, prawn, baim, in the coastal region. The study was carried out for a bele, bata, poa, koral, chewa, pangus, ramsosh, aire, period of 6 months from July to December, 2016. boal etc including other SIS (Small Indigenous 2.2 Methodology Species) are very high and available in the open water For this study, a combination of questionnaire bodies (Hossain et al., 2016). Numerous types of interview, Focus Group Discussions (FGD) and fishing gears are operated in the Tetulia River for crosscheck interviews were accompanied with key commercial fishing namely fishing nets, fishing traps, informants such as Upazila Fisheries Officer, local hooks and lines, wounding gears and fish aggregation leaders, NGOs workers and teachers according to device (Chakraborty et al., 1995). Charberjal is one Ahmed et al. (2010 and 2012). A total of 10 charberjal kind of fishing net that widely used in the Tetulia operation systems was observed and direct contacted River as well as in the coastal region of Bangladesh. A with 25 charberjal operated fishermen to collect the large number of fishermen involved in fishing by data. Samples of catches and their assessment were using charberjal in the Tetuila River including their carried out during the time of fishing for the study of surrounding small canals, submerged chars and catch composition. Samples were identified up to the inundated agriculture land and caught fish by making species level based on morphometric and meristic trap. Approximately 120 submerged chars is formed in characteristics. the Tetulia River due to siltation which inundated 2.3 Charberjal operational system daily in high tide and dry up in low tide due to tidal Charberjal is operated in the shoreline of rivers, action which is the main location for charberjal submerged chars and inundated agriculture land operation. In the coastal region, there is a tendency to including tiny canals all over the coastal region of harvest fish from natural sources by using various Bangladesh. Tidal water actions (high tide and low types of fishing device by the fishermen and even by tide) are used to operate this net. Fishermen get chance the local people which is one kind of common feature 10-12 days in each month to operate this net during due to existence of plentiful rivers, canals, inundated full moon and full dark. The mesh size of charberjal is floodplains and high availability of fish species varied from 0.3 to 0.5cm and locally this net is called (Hossain et al., 2017). On the other hand, there is no mosquito net. The length of the net may be 100-300 information or diminutive information on the riverine meter and height may be 1.5-2.0 meter depending on fish diversity, abundance of fish species, harvesting the operational place and fishermen ability. system, types of fishing gears used for fishing, The net is lay down during the last moment of threatened fish species in the open water as well as low tide in first-night. During setting the net, lower economics of fishermen in the coastal region of portion is fixed (buried) in soft bottom mud and upper Bangladesh. Several studies have already been done to porting is obscured