Health risk assessment of commercial fish and shrimp from the North Persian Gulf

BACKGROUND

Bioaccumulation of trace metals in the food web demands continuous monitoring of seafood safety. Here, the food safety of commercial fish bluespot mullet Crenimugil seheli, deep flounder Pseudorhombus elevates, and Jinga shrimp Metapenaeus affinis was assessed from commercial and industrial region of the West Bandar Abbas, the North Persian Gulf, for the first time.

METHODS

For this purpose, concentrations of trace metals Ni, Zn, Cu, Cr, Cd, and Pb, and their health risks were investigated.

RESULTS

Results showed the average concentration of all trace metals in all species was below concentrations proposed by WHO/FAO/USEPA. The finding on risk assessment of three species indicated three species are safe for daily consumption. Long-term consumption of three species would not pose potential non-carcinogenic health risk. However, it would result in carcinogenic effects from the ingestion of trace metals Ni, Cr, and Cd.

CONCLUSIONS

The data emphasizes the need for the continuous monitoring in this industrial region in the future to manage and control pollutant sources and to ensure the quality of seafood.

Intake of microplastics by commercial fish: A Bayesian approach

The disordered growth of large cities around water bodies causes environmental damage due to discarded plastics and microplastics (MPs) that aquatic organisms can ingest. This study analyzed the occurrence, type, and abundance of MPs in the gastrointestinal contents of four species of commercial fish (120 total specimens), namely, Brazilian mojarra (Eugerres brasilianus) and mullets (Mugil curema, Mugil curvidens, and Mugil liza), obtained in Porto Seguro in Bahia, Brazil, between March and May 2019. A priori probability distributions were generated using a Bayesian approach and simulations to assess MP intake based on varying exposure amounts (θ = 0.2, θ = 0.5, and θ = 0.8). E. brasilianus (53.33%) and Mugil spp. (41.66%) were contaminated with some types of MPs. Black, blue, and green MPs dominated in the extracted samples, and most measured 1.0 mm in length or smaller. The dominant polymers identified using Fourier transform infrared spectroscopy (FTIR) were polyester, polypropylene, semi-synthetic rayon fiber, and polyamide 6 (nylon). The a posteriori probabilities of more than half the E. brasilianus and Mugil spp. ingesting MPs were 0.336 and 0.008, respectively, indicating that E. brasilianus is much more likely to ingest MPs. These simulations can be useful tools for assessing the environmental quality and local anthropic impact of MP ingestion by fish populations.

Microplastic pollution in wild commercial nekton from the South China Sea and Indian Ocean, and its implication to human health

Marine biota, especially commercially important species, serves as a basis for human nutrition. However, millions of tons of plastic litter are produced and enter the marine environment every year, with potential adverse impacts on marine organisms. In the present study, we investigated the occurrence and characteristics of microplastic (MP) pollution in the digestive tracts of 13 species of wild nektons from 20 stations sampled in the South China Sea (SCS) and the Indian Ocean (IO), and assessed the human health risks of MPs. The detection rate of MPs ranged from 0.00% to 50.00% from the SCS, which was dramatically lower than that from the IO (10.00-80.00%). The average abundance of MP was 0.18 ± 0.06 items g wet weight^-1 (ww^-1) in the SCS, which was significantly lower than that in the IO with a concentration of 0.70 ± 0.16 items g ww^-1. Most MPs were fibers in type, black in color, and polyester (PES) in polymer composition in both the SCS and IO. Interestingly, distinct profiles of MP pollution were found between the benthic and pelagic nektons: 1) The predominant MP composition was PES in the benthic nektons, whereas polyamide (PA) accounted for a larger part of the total MP count in the pelagic nektons within the SCS; 2) The abundance of MP in the benthic nektons (0.52 ± 0.24 items individual^-1) was higher than that in the pelagic nektons (0.30 ± 0.11 items individual^-1). Accordingly, the mean hazard score of MPs detected in the benthic nektons (220.66 ± 210.75) was higher than that in the pelagic nektons (49.53 ± 22.87); 3) The mean size of the MP in the pelagic nektons (0.84 ± 0.17 mm) was larger than that in the benthic nektons (0.49 ± 0.09 mm). Our findings highlight the need to further investigate the ecological impacts of MPs on wild nekton, especially commercially important species, and its potential implications for human health.

Accumulation of microplastics in typical commercial aquatic species: A case study at a productive aquaculture site in China

The widespread occurrence of microplastics in the marine environment has drawn global attention because microplastics may impact the populations of marine organisms. As such, aquaculture industry may suffer from microplastic pollution, especially when plastic products are widely used for aquaculture. Here, we assessed the abundance and characteristics (type, size and composition) of microplastics in sediment and typical commercial species (fish, bivalves and shrimps) in an aquaculture site at Xiangshan Bay, which has been operated intensively for decades. Satellite remote sensing images revealed that aquaculture activities were associated with microplastic pollution in sediment, where the microplastics (51-88 items/kg dry weight) were mostly fibres (>94%) and between 500 and 2000 µm. Cellulose was the predominant polymer (60-88% of microplastic composition), followed by polypropylene. Microplastics accumulated in all the commercial species (0.95-2.1 items per individual), where shrimp (Parapenaeopsis hardwickii) had lower potential for microplastic accumulation than the other species. The predominance of fibres and cellulose in the commercial species implies their limited ability to recognize the type and composition of microplastics during ingestion. Given the limited accumulation of microplastics in these typical commercial species even at a productive aquaculture site, we suggest that microplastics may not increase the health risk of consuming seafood and their impacts on commercial species may be less deleterious than previously thought.

Resolution of the Portunusgladiator species complex: taxonomic status and identity of Monomiagladiator (Fabricius, 1798) and Monomiahaanii (Stimpson, 1858) (Brachyura, Decapoda, Portunidae)

The United States Food and Drug Administration (FDA) has recently adopted DNA barcoding for the purpose of determining the species identity of commercial seafood products. This effort has revealed instances of incongruence between current scientifically accepted taxon names and those utilized by the seafood industry in product labelling. One such case is that of "Portunushaanii", a name utilized by the seafood industry to label commercial products under the market name "red swimming crab." However, carcinologists currently regard P.haanii as synonym of Portunusgladiator Fabricius, 1798, which itself is the subject of debate over whether it is a secondary homonym of Cancer gladiator Fabricius, 1793. Further complicating matters, DNA barcode sequences from commercial products match GenBank sequences identified as Portunuspseudoargentatus Stephenson, 1961. Here the complicated taxonomic history of the Portunusgladiator complex is reviewed and a resolution proposed based on combined morphological descriptions and molecular phylogenetic analyses. It is demonstrated that, given the provisions of the International Code of Zoological Nomenclature and the current elevation of Monomia Gistel, 1848, to full genus rank, its type species, Portunusgladiator Fabricius, 1798, should be treated as a valid and available taxon name. It is also shown, upon examination and comparison of types and topotypic material that Monomiahaanii (Stimpson, 1858) is a distinct taxon from M.gladiator, and Portunuspseudoargentatus Stephenson, 1961, is a junior subjective synonym of M.haanii (Stimpson, 1858). Furthermore, it is shown that crab meat sold in the US currently labeled as "Portunushaanii" and/or "red swimming crab" is in fact M.haanii using comparative analysis of DNA barcode sequences between museum-vouchered reference specimens, whole crabs provided directly by a seafood importer, and processed commercial products purchased at retail.