Assessing Trace Elements Bioaccumulation in Coastal River Fish and Shellfish: Implications for Human Health and Risk Evaluation.

The presence of heavy metal contaminants in fish and shellfish in aquatic environments poses a risk to human health due to trophic transfer. This study determined the levels of various trace elements (Fe, As, Cr, Zn, Cu, Ni, Pb, and Cd) in the muscles, gills, and liver of hilsa (Tenualosa ilisha) and prawn (Macrobrachium rosenbergii) samples obtained from the Tetulia River, Bangladesh. The results showed that the level of trace elements in different body parts differed significantly (P < 0.05) between species, displayed below recommended threshold levels. The cumulative low to higher hierarchic concentration of the trace elements was as follows: Fe > Zn > Cu > Cr > Ni > Pb > As > Cd. Hilsa had significantly (P < 0.05) higher bioaccumulated trace elements compared to prawn. With the exception of Ni and Cd, the estimated daily intakes (EDI) for both adults and children were below the recommended daily allowance (RDA), which exhibits that other trace elements do not cause harm to human health. Furthermore, the hazard index (HI) and total hazard quotient (THQ) were also found to be within acceptable limits, taking into account the higher vulnerability of children to toxicity compared to adults. Notably, the HI suggested that children were approximately four times more susceptible to both carcinogenic and non-carcinogenic effects compared to adults. Ultimately, the levels of carcinogenic risk were deemed acceptable, despite the estimated values suggesting susceptibility to adverse effects in both adults and children. This study concluded that fish and shellfish may not pose a health risk to consumers, highlighting the importance of further monitoring of trace elements in the catchment area.

Temporal distribution of fishery resources in Payra River: relationship with climatological changes, ecological assessment, and threat assessment.

The Payra river is one of the large coastal rivers in Bangladesh which supports incredible fish species and has been affected by extensive human disturbance due to huge fishing pressure. The present study provides information about the temporal diversity of finfish and shellfish concerning climatological variables and ecological pollution along with threat assessment in the Payra river, Bangladesh. During the entire study, a total of 61 species including 56 finfish and 5 shellfish species were recorded under 22 families belonging to 11 orders. The order-wise fish species availability showed that the Perciformes (29.49%) was the dominant order based on species richness. Among them, 4 endangered, 6 vulnerable, 4 near threatened, 42 least concern, and 5 data deficient species were found. During the study period, the average Shannon-Weaver diversity index value was (3.33 ± 0.12) indicating a good spread of fish population in the Payra river. Average Margalef richness index value was found (7.60 ± 0.32), Pielou's evenness index (0.48 ± 0.05), and Simpson dominance index (0.93 ± 0.02) in the Payra river. The dominance and Richness index value indicates a clear water environment with slight pollution in the Payra river. Ten different kinds of fishing gears were identified under 3 major groups including 5 nets, 3 hooks and lines, and 2 traps. Canonical correspondence analysis ordination plot showed that rainfall was the most influencing driving force among the meteorological parameters. The cluster analysis based on the Bray-Curtis similarity matrix showed that the winter season formed a separate cluster. In the recapitulation, the Payra river is a highly productive system that provides a favorable environment for a large variety of finfish and shellfish species assemblages. The findings of the conducted study are expected to be helpful for the respective researchers, policymakers, managers, and conservationists for the sustainable management of this water body and the interconnected surrounding neighboring countries.

Nutritional, microbial and various quality aspects of common dried fish from commercial fish drying centers in Bangladesh.

The purpose of this study was to evaluate the nutritional, microbial and sensory quality of five dried fish species from five fish drying centers in Bangladesh, and consumers' perception on quality and perceived health problems of consuming dried fish. Proximate composition and bacterial load were determined following AOAC and total plate count method, respectively. Data on peoples' perception regarding the quality aspects of dried fish were collected using a structured questionnaire. Sensory analysis showed samples from Cox's Bazar had higher acceptability than other regions. Moisture content ranged from 12.00 ± 1.12% to 22.99 ± 1.09%, the highest found in Bombay duck from Patuakhali. The highest values of protein were found in shrimp from Chittagong (64.33 ± 0.99%) and the lowest in Bombay duck from Bhola (51.80 ± 0.95%). The lipid content varied from 5.38 ± 0.37% (Bombay duck from Cox's Bazar) to 8.67 ± 0.96% (Bombay duck from Khulna). The ash content was ranged from 13.89 ± 0.94% to 20.07 ± 1.64% in Bombay duck from Patuakhali and Cox's Bazar. The mean total plate count of dried Bombay duck were 7.1 ± 0.2×107, 9.8 ± 0.1×107 and 7.8 ± 0.52 × 107 cfu/g, whereas, total Vibrio spp. count were estimated 1.1 ± 0.1×103, 3.7 ± 0.2×105 and 1.8 ± 0.1 × 105 cfu/g for Chittagong, Cox's Bazar and Bhola, respectively. The pathogenic bacterial species E. coli and Salmonella sp. were absent in dried Bombay duck from all locations. Of 500 respondents, the majority (94.8%) reported no complications after consuming dried fish. Significant quality variation among the dried fish samples suggested further improvement in dried fish quality through maintaining hygiene and sanitation to produce quality and safe dried fish for the consumers in home and abroad.