Microplastics in commercially important seafood species is an emerging area of food safety concern. While there have been reports of plastic particles in the gastrointestinal tract of several species, presence of microplastics in edible fish tissues has not yet been reported from India. This study examined the presence of microplastics in the edible (muscle and skin) and inedible (gill and viscera) tissues of nine commercially important pelagic fish species from Kerala, India. A total of 163 particles consisting mainly of fragments (58%) were isolated. Out of 270 fishes analysed (n = 30 per species), 41.1% of the fishes had microplastics in their inedible tissues while only 7% of fishes had microplastics in their edible tissues. The quantity of microplastics in inedible tissue was significantly larger in filter feeders than, that in visual predators (p < 0.05). The average abundance of microplastics in edible tissues was 0.07 ± 0.26 items/fish (i.e., 0.005 ± 0.02 items/g) and was 0.53 ± 0.77 items/fish (i.e., 0.054 ± 0.098 items/g) in inedible tissues. The results suggest the possibility of human intake of microplastics by the consumption of pelagic fishes from this region, albeit in small quantities.

A comprehensive analysis of 15 target chemical compounds (pharmaceuticals and personal care product, perfluoroalkyl compounds and industrial chemicals) were carried out to determine their concentrations in selected commercially exploited, wild caught small and medium sized pelagic fish species and their organs (Thyrsites atun (snoek), Sarda orientalis (bonito), Pachymetopon blochii (panga) and Pterogymnus laniarius (hottentot)) obtained from Kalk Bay harbour, Cape Town. Solid phase extraction (SPE) method based on Oasis HLB cartridges were used to concentrate and clean-up the samples. Liquid chromatography–mass spectrometry analysis of these chemical compounds revealed the simultaneous presence of at least 12 compounds in different parts of the selected fish species in nanogram-per-gram dry weight (ng/g dw) concentrations. The results revealed that perfluorodecanoic acid, perfluorononanoic acid and perfluoroheptanoic acid were the most predominant among the perfluorinated compounds and ranged between: (20.13–179.2 ng/g), (21.22–114.0 ng/g) and (40.06–138.3 ng/g). Also, diclofenac had the highest concentration in these edible fish species out of all the pharmaceuticals detected (range: 551.8–1812 ng/g). The risk assessment values were above 0.5 and 1.0 for acute and chronic risk respectively which shows that these chemicals have a high health risk to the pelagic fish, aquatic organisms and to humans who consume them. Therefore, there is an urgent need for a precautionary approach and the adequate regulation of the use and disposal of synthetic chemicals that persist in aquatic/marine environment in this province and other parts of South Africa, to prevent impacts on the sustainability of our marine environment, livelihood and lives.

Although weekly consumption of fish is recommended, the presence of contaminants in seafood has raised many concerns regarding the benefits of fish intake. In the present study microplastics (MPs) and metals’ concentration in muscles of both benthic and pelagic fish species from northeast of Persian Gulf were investigated and the risk/benefit of their consumption was assessed. The results demonstrated that MPs and Hg in all species and Se in benthic species increase with size, while relationship between other metals, and fish size is not consistent. Consumption of a meal ration of 300 and < 100 g/week for adults and children, respectively, is recommended since it would provide the required essential elements with no human health risk. On the other hand, the estimated intake of MPs from fish muscles revealed that the mean intake of MPs for P. indicus, E. coioides, A. djedaba, and S. jello consumption is 555, 240, 233, and 169 items/300 g-week, respectively. Moreover, the relationship between MPs and metals in fish muscles were positive for A. djedaba, and negative for E. coioides. Considering the chemical toxicity of MPs and metals, and their good linear relationships in some species, consumption of high doses of the studied fish may pose a health threat to the consumers.

The environmental behavior of microplastics (MPs) in estuaries with saline and freshwater intersections is extremely complex. This increases the chance of MP ingestion by fishery resources, posing potentially tremendous health risks for humans. Herein, a total of 105 fishes from 14 different species, and 86 crustaceans (including shrimps and crabs) from five different species were sampled in the Yangtze River estuary and offshore, and MP bioaccumulation, accumulative organ, and the influencing factors were comprehensively studied. The results elucidated that MP accumulation in benthos was significantly higher than that in pelagic animals due to the lower acceptance threshold, assimilation efficiency and egestion rate for benthos. The MP content in crustaceans with the burrowing favoring the MP retention was significantly higher than that in fishes. MPs ingested by fish can accumulate in skin, gills and viscera rather than muscles. Most MPs accumulated in fishery resources were cellulose and polyethylene terephthalate characterized by black and gray fibrous and lengths ranging from 0.1 mm to 1 mm. The gill retention capacity of pelagic fish to smaller-size (<0.1 mm) MPs was pronouncedly stronger than that of benthic fish. It was more accurate to assess the ecological risk of MPs in terms of the maximum size of MPs accumulated in organisms. Compared with the offshore area, the incidence of MP uptake was higher in the estuary owing to anthropogenic impacts. This study helps understand the transfer of MPs in aquatic food webs and offers a foundation for assessing the risk of human exposure to MPs.

Plastic marine debris hyper-concentrates hydrophobic contaminants such as polycyclic aromatic hydrocarbons (PAHs) and can transfer these sorbed contaminants to biota following ingestion. PAHs are known to induce cardiotoxicity and visual toxicity at sublethal doses. Juvenile White seabass (Atractoscion nobilis) fish were fed environmentally relevant concentrations of either virgin polystyrene or benzo(a)pyrene (BaP)-sorbed polystyrene for 5 days and were monitored for changes in phototactic response, swimming behavior, and hepatic cytochrome p450 1A (CYP1A) enzyme activity. No significant differences in the monitored endpoints were recorded in fish that ingested either polystyrene or BaP-sorbed polystyrene relative to control fish following the short-term exposure. However, fish exposed to 252 μg/L BaP alone as a positive control had significantly elevated CYP1A enzyme activity (p = 0.046) and impaired phototactic response (p = 0.020), though no altered swimming behavior was observed (p = 0.843) relative to control fish. These results demonstrate that pelagic fish ingesting environmentally relevant concentrations of BaP-sorbed polystyrene for a short, 5-day duration do not demonstrate measurable changes in vision, swimming activity, nor CYP1A activity. High variability within enzyme activity and behavioral responses suggest that lack of significant effects may be due to low sample size.

Existing evidence indicated that dichlorodiphenyltrichloroethane (DDT)-containing antifouling paints were an important source of DDT residues to mariculture zones. However, the magnitude of the impact on aquafarming environment has remained largely unknown. In the present study, the concentrations of DDT and its metabolites (designated as DDXs) were determined in harbor sediment and antifouling paint samples collected from a typical mariculture zone in South China. Compositional and concentration correlation analyses implicated the DDT-containing antifouling paints for fishing boat maintenance as an important source of DDT in the mariculture zone. The annual emission of DDXs to the study region was estimated at 0.58tons/yr. Furthermore, a comparison of the expected DDT loadings in pelagic fish and field measurements indicated that fish feed especially trash fish was a major source of DDTs in the fish body. Nevertheless, the use of DDT-containing antifouling paints should be limited to prevent further deterioration in aquafarming environment.

Indo-Pacific humpback (Sousa chinensis) dolphins are primarily exposed to chlorinated organic contaminants through the consumption of contaminated fish. We assessed the potential risk of chlorinated organic contaminants to Indo-Pacific humpback dolphins by determining the concentration of 21 organochlorine pesticides (OCPs) and 28 polychlorinated biphenyls (PCBs) in 14 fish species collected from the South China Sea coastal waters. The results of the study showed that bioaccumulation of OCPs and PCBs was influenced by sampling location, fish species, and fish niche. The average ∑DDT (Dichlorodiphenyltrichloroethane) concentration was 3 times higher in benthopelagic fish (488 ng/g) compared to pelagic-neritic fish (155 ng/g) from Jiangmen, whereas an opposite pattern of the lower DDTs concentration in benthopelagic and demersal fish compared to pelagic fish from Zhuhai (p < 0.05). Furthermore, the molecular diagnostic ratios using DDT and its metabolites (DDT/(DDD + DDE) were less than one, suggesting the DDT contamination at Zhuhai and Jiangmen may due to the historical agricultural usage of the lands. The reference dose-based (RfD) risk quotient (RQ) suggested that DDTs are potential risk in Qinzhou, which is in accordance with the high DDTs concentration found in fishes captured in Qinzhou. The RfD risk quotient of PCBs is at potential risk for all sites (RQ > 100), except Xiamen and Qinzhou. A highest average ∑DDT concentration was observed Qinzhou. This study showed that fish consumption might pose a health risk to Indo-Pacific humpback dolphins. However, further studies are required to determine the contribution of fish niche to the overall risk.