Journal of Fisheries

Microplastic pollution in edible marine fish from the northwestern Bay of Bengal, Bangladesh: A comprehensive assessment of occurrence, characteristics and associated ecological risks

2026-03-05T07:28:04+00:00

Microplastic (MP) pollution is an emerging environmental issue with serious implications for marine ecosystems and potential risks to human health. This study assessed MP contamination in the gastrointestinal tracts of 130 individuals representing 13 species (n=10 species^–1) from the Bay of Bengal, Bangladesh. A total of 892 MP particles were detected, confirming ubiquitous contamination across all species. MP abundance ranged from 3.70–12.00 items per individual (mean±SD: 6.87±1.08 items fish^–1). Five morphotypes: fibers, films, foams, pellets, and fragments were identified, with fibers constituting the dominant category. Most MPs were <5 mm, and red was the most common color. MP abundance exhibited a moderate positive correlation with body length (r=0.41), indicating that larger individuals tended to contain higher numbers of MP. Benthopelagic species exhibited the highest MP ingestion (7.85±2.58 items fish^–1), while carnivorous fishes showed greater contamination (7.13±2.59 items fish^–1) among trophic guilds. Risk assessment revealed that contamination factor (CF) ranged from 1.00–3.24, indicating moderate to high levels of MP contamination. The overall polymer load index (PLI) was 1.76, corresponding to a low pollution risk category. However, polymer hazard index (PHI) analysis revealed dominance of moderate-risk polymers, including polyester and PP–PE copolymer, with high-risk polymers such as nylon (PHI = 8.80) and PVC (PHI = 7.00) contributing substantially to overall hazard. These findings provide baseline evidence of MP contamination in Bangladeshi marine fisheries and highlight the need for future studies integrating polymer toxicity, trophic transfer, and human exposure pathways to support effective mitigation strategies.

Sustainable freshwater fisheries in Bangladesh: problems and pathways forward

2026-03-05T07:28:18+00:00

Bangladesh is one of the leading countries in global fish production; however, numerous problems and challenges persist. This paper summarises the problems faced by seven major stakeholder groups in the country’s fisheries sector: (i) fish farmers, (ii) freshwater fishermen, (iii) fish traders, (iv) fish seed producers, (v) fisheries administrators and extension personnel, (vi) researchers and (vii) fish consumers. Fish farmers reported 19 problems, with transportation issues being the most common (35% of respondents), followed by the lack of quality fish seed (20%). Freshwater fishermen reported 13 problems, with reduced fish catch as the most common (65%), followed by the shrinkage of fishing habitats (15%). For freshwater fish traders, lack of preservation and storage facilities was the most common problem, reported by 80% of respondents. Seven problems were reported by finfish seed producers; among the top-ranked, lack of quality brood and its high price were most common, reported by 60% and 40% of respondents respectively. Fisheries administrators and extension personnel reported nine problems, with insufficient manpower being the most common, reported by 70%. Eleven problems were reported by fisheries researchers, with inadequate research funding as the most common, reported by 60%. Fish consumers reported five problems, including price hikes and insufficient supply of native fishes. The results of this study will be useful in prioritising problems and formulating effective policies for the sustainable development of the fisheries sector in Bangladesh and other countries facing similar challenges.

Farm to policy: Socioeconomic dynamics and occupational challenges of freshwater fish farmers in the Cauvery Delta region, Tamil Nadu

2026-03-05T07:28:32+00:00

Freshwater aquaculture is vital for global food security and rural livelihoods. This study examined 120 fish farmers across Thanjavur, Thiruvarur, and Nagapattinam districts in Tamil Nadu's Cauvery Delta to understand socioeconomic dynamics and constraint hierarchies shaping aquaculture development. Using structured interviews and Garrett ranking, the research revealed critical structural vulnerabilities: the farming population is predominantly male (93.3%), aging (average 45 years; 79.2% middle-aged or older), and faces future labour succession challenges despite relatively high literacy (85% educated). Low organizational participation (54.2% non-members) undermines collective bargaining capacity. Most farmers (80.8%) combine aquaculture with other occupations, reflecting income insufficiency rather than strategic diversification. With 65% representing first-generation farmers averaging eleven years' experience, aquaculture emerges as recent livelihood diversification rather than traditional practice. Landholding patterns showed 75% farm ownership averaging 3.5 acres, though 53.3% operate small farms below three acres, limiting economies of scale. Caste composition revealed predominance of marginalized communities—61.7% Other Backward Class and 27.5% Scheduled Caste—facing systematic barriers to credit, technology, and market access. Constraint analysis identified high feed costs as the primary short-term barrier across all districts, followed by insufficient credit access and inadequate extension services, while low farm gate prices emerged as the dominant long-term constraint. Findings demonstrate that effective aquaculture policies must address structural inequities rooted in caste-based exclusion, land fragmentation, organizational deficits, and market asymmetries through targeted interventions including collateral-free credit, farmer producer organizations, district-level feed cooperatives, and differentiated extension programming to transform aquaculture into dignified, profitable livelihoods.

Modelling of 2,4-dichlorophenol, an emerging pollutant removal from water by adsorption onto sugarcane bagasse biochar using response surface methodology

2026-03-05T07:28:45+00:00

This study evaluated the potential of sugarcane bagasse biochar as a low-cost adsorbent for removing 2, 4-dichlorophenol (2, 4-DCP), an emerging pollutant from water using adsorption modelling and response surface methodology. It aimed to determine optimal combinations of concentration, contact time, pH and dose for maximizing contaminant uptake in batch and column systems. Batch adsorption experiments were planned using a Box–Behnken response surface experimental design with initial 2, 4-DCP concentration (25, 50, and 75 mg L^–¹), contact time (20, 40, and 60 min), solution pH (5, 7, and 9), and biochar dosage (6.25, 12.5, and 25 mg). Fixed-bed column studies were conducted under continuous flow to assess dynamic performance and breakthrough behaviour. Adsorption equilibrium, kinetics and column behaviour were analysed using standard isotherm and kinetic models, supported by surface and functional-group characterization. The optimized batch conditions produced removal efficiencies of about 95% with high monolayer adsorption capacity on a homogeneous biochar surface. The equilibrium data followed a monolayer adsorption model, while kinetic analysis indicated rapid uptake controlled primarily by surface-site availability. Column studies showed high dynamic capacity and well-defined breakthrough characteristics under the tested flow conditions. Sugarcane bagasse biochar proved to be an efficient and technically suitable material for removing phenolic contaminants such as 2, 4-DCP from water. The findings demonstrate a productive use of agro-industrial waste for water purification and support its application in practical treatment units for removing emerging pollutants in aquatic environments.

An annotated checklist of ichthyofauna and associated estuarine biota of the Manakudy Estuary, southern Tamil Nadu, India

2026-03-05T07:28:58+00:00

This study assessed the ichthyofaunal and associated floral diversity of the Manakudy Estuary, southwest coast of India, over a two-year period involving monthly surveys from August 2023 to July 2025. Sampling efforts were stratified across three distinct ecological zones i.e., freshwater influx region (Station 1), mid-mangrove area (Station 2), and estuarine mouth region (Station 3), utilizing traditional fishing crafts and standardized visual census methods to capture spatial heterogeneity. A total of 120 species were recorded, representing 37 orders, 62 families, and 89 genera. The order Eupercaria incertae sedis showed the highest species richness (15.83%), followed by Carangiformes (12.50%) and Clupeiformes (8.33%). Among families, Carangidae was the most dominant with 13 species. Conservation assessment revealed the occurrence of threatened species, including the Endangered honeycomb stingray (Himantura uarnak) and the Vulnerable Coromandel whipray (Brevitrygon imbricata), along with two near threatened species. These findings provide baseline information essential for long-term biodiversity monitoring, sustainable fisheries management, and conservation planning in the Manakudy Estuary.