Status of fish biodiversity and fishing on Hau River, Mekong Delta, Vietnam

2020 ◽  
Vol 56 ◽  
pp. 14
Author(s):  
Vu Ngoc Ut ◽  
Au Van Hoa ◽  
Huynh Phuoc Vinh
Keyword(s):  
Species Composition ◽  
Fish Species ◽  
Mekong Delta ◽  
Middle Part ◽  
Fishing Ground ◽  
Sampling Gear ◽  
Fish Biodiversity ◽  
Gill Net ◽  
Fishing Gears ◽  
The Status

Fish biodiversity on Hau (Bassac) river was investigated to assess the status of species composition and fishing by fishing gears during a year. Sampling was implemented monthly at the upper part (An Giang province), middle part (Can Tho City) and lower part (Soc Trang province) of Hau River using trawl net as main sampling gear. Additionally, fish composition was also recorded from four other most popular fishing gears including cast net, gill net, fixed net and hook operated in the study sites. Fish species composition was determined by fishing gears and their abundance (CPUE) was calculated only from the main sampling gear (trawl net). The results showed that a total of 176 fish species belonging to 16 orders and 49 families was recorded. Perciformes was the most abundant group with 51 species followed by Cypriniformes with 46 species. The number of fish species was decreasing from upper part to lower part. Trawl net was considered the most destructive gear as up to 145 fish species caught by this device, followed by gill net with 98 species, fixed net 75, cast net 57, and hooks 16 species. CPUE was very low ranging from  0.53 kg.ha−1 h−1 to 26.30 kg.ha−1 h−1. Higher CPUE was recorded at lower part in compared to upper part and middle part, and at dry season in compared to rainy season. Regulation on fishing gears, fishing ground and season should be taken into consideration to protect and conserve the resources.

scholarly journals Catch assessment of artisanal marine fishing gears in Cox’s Bazar and Teknaf of Bangladesh

2016 ◽  
Vol 27 (2) ◽  
pp. 228-234
Author(s):  
SK Ghosh ◽  
MK Ahsan ◽  
MK Ahmmed ◽  
SI Ahmed ◽  
MM Hasan ◽  
...  
Keyword(s):  
Fish Species ◽  
Fishing Gear ◽  
Catch Per Unit Effort ◽  
Beach Seine ◽  
Gill Net ◽  
Fishing Gears ◽  
Dominant Fish ◽  
Commercially Important ◽  
Marine Fishing ◽  
Harpadon Nehereus

Studies were conducted on catch assessment of some artisanal marine fishing gears operated in Cox’s Bazar and Teknaf areas from April 2014 to April 2015. Sixteen types of fishing gears were identified, of which gill net, beach seine net, estuarine set bag net, marine set bag net and trammel net occupy major fishing activities. Although estuarine set bag net (ESBN) is a legally restricted fishing gear recorded the highest catch per unit effort (CPUE) (110 kg/gear/day) in July followed by marine set bag net (MSBN) (105 kg/gear/day) in Cox’s Bazar and the highest CPUE was recorded 100 kg/gear/day by ESBN in June followed by MSBN (90 kg/gear/day) in Teknaf. Out of 52 species of fishes, the major fish species abundantly caught by these gears were Poa (Otolithoides argenteus), Churi (Trichiurus haumela), Loittya (Harpadon nehereus), Ranga choukha (Lutjanus johni), Lal poa (Johnius argentatus), Olua (Coilia dussumieri), Rup chanda (Stromateus chinensis), (Stromateus argenteus) and Ilish (Tenualosa ilisha). Besides these fish species, 10 commercially important shrimp species and 3 important crab species were also recorded during the study period. The peak season of availability of most fish species was June and July while lean season was December and January. This study indicated that Otolithoides argenteus) was the dominant fish species followed by Trichiurus haumela, Harpadon nehereus and Coilia dussumieri.Progressive Agriculture 27 (2): 228-234, 2016

scholarly journals Fish Diversity and Its Threatened Status of the Dharla River in Bangladesh

2021 ◽  
Vol 79 (4) ◽  
pp. 163-172
Author(s):  
Md. Ashraful Alam ◽  
Yeasmin Ara ◽  
Imran Parvez ◽  
Jayanto Kumar Roy ◽  
Macksood Alam Khan
Keyword(s):  
Fish Species ◽  
Diversity Indices ◽  
Fish Diversity ◽  
Indigenous Species ◽  
Local Data ◽  
Exotic Fish ◽  
Fish Biodiversity ◽  
Fishing Gears ◽  
Threatened Status ◽  
Destructive Fishing

Abstract Fish diversity of a riverine ecosystem became reduced due to different manmade and natural calamities. This study investigated the present fish biodiversity status of the Dharla River located (25.8103° N, 89.6487° E) in the northern part of Bangladesh from January to December 2018. In this study, the existing fish biodiversity status of the Dharla River was estimated in terms of diversity indices and threatened status (both global and local). Data was collected from the three sampling sites of the river using different fishing gears and three selected fish markets located in the Kurigram district of Bangladesh. A total of 76 fish species were identified belonging to 8 orders, 26 families and 57 genera. The Cyprinidae was the most dominant family represented by 14 species followed by the Danionidae (13 species), Bagridae (8 species) and few minor families. Apart from the indigenous species, nine exotic fish species were also recorded. The Shannon-Weaver diversity (H), Pielous evenness (e) and Margalef richness (D) indices ranged from 3.00 to 3.71, 0.62 to 0.94 and 3.94 to 7.95, respectively. Out of 76 indigenous species, 28 species (37%) were identified as threatened in Bangladesh, which included critically endangered (4), vulnerable (9) and endangered (15) species. Indiscriminate fishing through poisoning and destructive fishing gears were identified as the major threats to fish biodiversity of the Dharla River. Thus, the river serves as considerable support for threatened indigenous fishes. Therefore, necessary steps are needed to stop destructive fishing, establish permanent fish sanctuaries and proper monitoring for maintaining sustainable biodiversity in the Dharla River.

scholarly journals CATCHABILITY AND DIVERSITY OF FISH SPECIES CAPTURED BY GILL NET IN NEW CALABAR RIVER, NIGERIA

2020 ◽  
Vol 26 (2) ◽  
pp. 107
Author(s):  
Olaniyi Olopade ◽  
Henry Eyina Dienye ◽  
Ogheneforon Oderhohwo ◽  
Nathanael Akinsafe Bamidele
Keyword(s):  
Fish Species ◽  
Wiener Index ◽  
Diversity Indices ◽  
Fish Diversity ◽  
Catch Per Unit Effort ◽  
Fish Family ◽  
Gill Nets ◽  
Gill Net ◽  
The Status ◽  
Sarotherodon Melanotheron

The aim of this study was to analyze fish species caught by gill nets and fish diversity of the New Calabar River. Three sampling stations were set based on the coverage situation of the river and ichthyofauna associated with gill nets were sampled twice monthly from February to July 2018. A total of 3,251 fish specimens, representing 11 orders, 15 families, and 28 species, were captured. The order Perciformes was identified as the most abundant representing five families while the remaining had one family each. The fish family Cichlidae was the most represented with seven species, and other notable families were Alestidae, Clupeidae, and Mugilidae, representing three species each. Prominent among the fish caught monthly included Liza falcipinnis, Mugil cephalus, Sarotherodon melanotheron, Sarotherodon galilaeus, Coptodon guineensis, and Sardinella maderensis. The mean catch per unit effort (CpUE) ranged from 3.15±0.2 to 4.85±0.2 kg unit-1 day11. Results of diversity indices revealed that Shannon-Wiener index values varied between 2.64 and 2.82, Simpson diversity ranged from 0.07 to 0.10, and Pielou’s evenness index values ranged from 0.85 to 0.95. The values obtained in this study showed that the status of fish diversity in New Calabar River was stable.

scholarly journals ABUNDANCE AND BIOMASS ESTIMATES OF COMMERCIAL FISH SPECIES USING HYDRO-ACOUSTIC METHOD IN JAKARTA BAY, INDONESIA

2015 ◽  
Vol 21 (1) ◽  
pp. 39
Author(s):  
Andria Ansri Utama ◽  
Setiya Triharyuni
Keyword(s):  
Fish Species ◽  
Poverty Alleviation ◽  
Fish Assemblages ◽  
Sustainable Livelihoods ◽  
Acoustic Method ◽  
Fishing Ground ◽  
Series Data ◽  
Abundance Estimation ◽  
Commercial Fish ◽  
Fishing Gears

The Jakarta Bay is known as a fishing ground area for several traditional types of fishing gears. The fishery has important role to provide nutrition, sustainable livelihoods, and poverty alleviation around the area. Abundance estimation of commercial fish species in the Jakarta Bay is essential particularly comparable of series data in order to evaluate the potential changes in distribution and abundance. The purpose of this study is analyzing the distribution of commercial fish species in the Jakarta Bay and estimate their abundance and biomass. Fish assemblages were concentrated in the eastern and central part of bay. Apparently salinity and DO associated with rich density of phytoplankton and zooplankton may explain the spatial variability of short-bodied mackerel and pony fish, while assemblages pattern of spiny hairtail and croaker might be driven by the availability of small planktivorous fish as their diet. The most abundant commercial fish in the Jakarta Bay are Short-bodied mackerel (<em>Rastrelliger brachysoma</em>), Ponyfish (<em>Leiognathus</em> sp.), Croaker (<em>Johnius</em> sp.) dan Spiny hairtail (<em>Lepturacanthus savala</em>) respectively. Furthermore, biomass estimates for those species showed short-bodied mackerel has the highest biomass followed by spiny hairtail, croaker, and ponyfish.

scholarly journals Fish catch composition of selected small scale fishing gears used in the Bonny River, Rivers State, Nigeria

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Olaniyi Alaba Olopade ◽  
Nkuene Gbenekanu Sinclair ◽  
Henry Dienye
Keyword(s):  
Fish Species ◽  
Small Scale ◽  
Wet Season ◽  
Gill Net ◽  
Long Line ◽  
Significant Difference ◽  
Fishing Gears ◽  
Fish Catch ◽  
Catch Composition ◽  
Rivers State

Fish catch composition of some selected small scale fishing gears (gill net, cast net, beach seine and long line) were investigated in Bonny River, Rivers State, Nigeria from August 2014 to January 2015. A total number of 25 fish species from 18 families were recorded during the study. The Mugilidae with only one species constituted the dominant family while Cichlidae, Lutjanidae, Clupeidae, had three species and Scianidae had two species of fish caught and the remaining families had one species each. Mugil cephalus constituted 28.48% of the total catches followed by C. nigrodigitatus (22.48%). In the dry season M. cephalus forms the major component landings (32.65%), followed by C. nigrodigitatus (26.53%) and S. galilaeus (12.24%) while in the wet season M. cephalus (31.06%), C. nigrodigitatus (18.63%) and T. zillii (11.80%) were the dominant fish species. Cast net was the most efficient fishing gear while gill net was the least efficient. The comparison analysis between the wet and dry seasons using t-test showed no significant difference between dry and wet seasons (t = 0.092, P > 0.05).

scholarly journals Fish species composition and size structure exploited by gill net fishery in The New Calabar River, Nigeria

2019 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Olaniyi Alaba Olopade ◽  
Henry Eyina Dienye ◽  
Ogheneforon Oderhohwo
Keyword(s):  
Species Composition ◽  
Fish Species ◽  
Size Structure ◽  
Mesh Size ◽  
Maximum Size ◽  
Abundant Species ◽  
Fish Stock ◽  
Size Selectivity ◽  
Gill Nets ◽  
Gill Net

The purpose of this study was to investigate the species composition and size selectivity of gillnets commonly used by the artisanal fishers in the New Calabar River, Rivers State, Nigeria. The data was collected during February-July 2018 from 3 sampling stations: SI Choba, S2 Ogbogoro, and S3 Iwofe all along the stretch of the river. Twenty-eight fish species were found belonging to 15 families. The prevalent families were Cichlidae, Mugilidae and Clupeidae representing 32.22%, 30.36% and 10.23% of the total catch, respectively. The most dominant species in terms of number were Liza falcipinnis (12.58%) and Mugil cephalous (12.26%) while in terms of biomass, the most abundance species were Xenomystus nigri (24.12%) and Lutjanus agennes (12.50 %). The girth and total lengths of the fishes ranged from 5.20±0.20 to 21.00±0.00 cm and 8.85±0.15 to 28.19±1.13 cm respectively. The length at first capture (L50%) for the most abundant species (Liza falcipinnis) was calculated to be 14.13 cm while that of L25% and L75% were 12.70cm and 15.25cm respectively. It was concluded that the gill nets used in the New Calabar River exploit fish species of small sizes and few medium sized specimens relative to species potential maximum size. It is therefore recommended that for an improved and sustainable exploitation fish stock of the New Calabar River, the use of gillnets of less than 25 mm-mesh sizes and “other gears” should be prohibited.Keywords: gill nets; species composition; mesh size; selectivity; New Calabar River

scholarly journals A comparative study on fish biodiversity with conservation measures of the Bhairabriver, Jessore, Bangladesh

2017 ◽  
Vol 3 (3) ◽  
pp. 357-367 ◽  
Author(s):  
Md Ashraful Islam ◽  
Abdulla Al Asif ◽  
Md Abdus Samad ◽  
Baadruzzoha Sarker ◽  
Meraz Ahmed ◽  
...  
Keyword(s):  
Habitat Degradation ◽  
Management Strategies ◽  
Community Members ◽  
Group Discussions ◽  
River Bank ◽  
Fish Biodiversity ◽  
Conservation Measures ◽  
Gill Net ◽  
Fishing Gears ◽  
Degraded Ecosystems

The present study was concerned to assess the present status of biodiversity in the Bhairab river, Jessore with its conservation measures. The study was based on primary observations, questionnaire interviews with 50 fishers, focus group discussions with river bank community members and cross-check interviews with key informants. The study was conducted for a period four months from May to August, 2016. The objective of the study was to assess the fish biodiversity in the Bhairab river, understand the existing fishing practices of the river and to identify proper management strategies for the conservation of fish biodiversity. Results of the study revealed that three kinds of fishers were engaged in the Bhairab river namely, professional fishers; seasonal fishers and subsistence fishers. Seven types of fishing gears like seine net, gill net, cast net, push net, lift net, trap and hook and line were operated to fish by the fishers during the survey. A total of 39 species of fish were identified in the catches of the Bhairab River. There are degraded ecosystems and declining biodiversity have found during the study. According to survey, fishing pressure and over fishing were responsible for almost 38% loss and pollution and siltation caused about 27% loss of ecosystem. Around 21% and 14% loss of ecosystem were caused by urbanization and human encroachment, and the recreational activities respectively. These have been created a great impact on river ecology. As a result, the water quality is deteriorating day by day and the availability of fish species and other aquatic biodiversity is decreasing gradually. During the survey, 20 species was found at a risk of being endangered. From the survey, it was found that the overexploitation of fish was responsible for the 40% losses of biodiversity in the Bhairab River and water pollution caused 35% loss of biodiversity. Henceforth, river course change and habitat degradation resulted in 15% and 10% loss of biodiversity of the river respectively. This study was identified possible ways to achieve a rich fish biodiversity in the Bhairab River with social, economic and environmental aspects. The specific recommendations are included community based fisheries management, establishment of sanctuary, control of pollution, maintenance of fishing gears and the implementation of fish act for conservation of fish biodiversity of the Bhairab River.Asian J. Med. Biol. Res. September 2017, 3(3): 357-367

DAMPAK PENGOPERASIAN ALAT PENANGKAP IKAN TERHADAP SUMBERDAYA IKAN RAWA DANAU BANGKAU THE (IMPACT OF FISHING GEARS TO SUSTAINABILITY OF FISHERIES AT DANAU BANGKAU SWAMP WATERS)

2016 ◽  
Vol 2 (4) ◽  
pp. 131
Author(s):  
Mijani Rahman
Keyword(s):  
Standard Length ◽  
Fish Population ◽  
Fishing Ground ◽  
Fish Production ◽  
Fishing Activity ◽  
Gonad Maturity ◽  
Fishing Season ◽  
Gill Net ◽  
Fishing Gears ◽  
The Impact

Secara kualitatif, produksi ikan dari Danau Bangkau dalam beberapa tahun terakhir mengalami penurunan, terutama ikan-ikan ekonomis penting. Ikan-ikan yang berukuran layak konsumsi mulai jarang ditemukan dan salah satu penyebabnya diduga karena intensitas penangkapan yang tinggi. Evaluasi dampak pengoperasian alat penangkap terhadap populasi  ikan merupakan langkah awal yang perlu dilakukan untuk menyusun srategi pemanfaatan sumberdaya ikan yang berkesinambungan. Hasil pengukuran terhadap panjang baku dan tingkat kematangan gonada ikan yang tertangkap menunjukan bahwa alat penangkap yang dioperasikan di rawa Danau Bangkau tergolong alat penangkap yang tidak selektif terhadap ukuran ikan yang tertangkap dan berpotensi memutus daur repopulasi ikan (kecuali horizontal gill net). Pembatasan daerah penangkapan, musim penangkapan dan pengaturan zona penangkapan merupakan solusi terbaik agar aktivitas penangkapan dapat memberikan manfaatyang optimal.Base on qualities category, a fish production from Danau Bankau swamp waters in some years later was reducing, especially in commercialize fish,  and one of causing this problem was a high fishing intensity. The evaluasion of fishing gears impact to fish population have been required to made a concept of sustainable fishing strategy. The measurement of standard length and gonad maturity of fish specimens showed all kind of fishing gears that operated in Danau Bangkau swamp waters included a selectiveness fishing geard category (excepted horizontal gill net) and could be broken to repopulation. A regulation of fishing ground, fishing season and fishing zone have a best solution in order to optimize of fishing activity.

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