Microplastic transfer from the American horseshoe crab to shorebirds through consumption of horseshoe crab eggs in Jamaica Bay, NY

Plastic ingestion by three species of Scylla (Brachyura) from the coastal areas of Thailand

This study marked the first investigation into the presence of plastic particles in the stomachs of three mud crab species (Scylla olivacea, S. paramamosain and S. tranquebarica) collected across the Andaman Sea and the Gulf of Thailand. The highest number of plastic particles in the stomach of crab samples was polyethylene (PE) that contributed 88.5 %; while green was the predominant colour (60.3 %). Ingested particles recovered from the stomachs of crabs differed significantly between species and sites (p < 0.001). The average number of plastic particles per individual was 2.3 ± 8.6 in Scylla olivacea, 7.2 ± 16.9 in S. paramamosain, and 13.5 ± 48.9 in S. tranquebarica. Satun, revealed the highest number of plastic particles recovered from mud crabs, while the lowest number of plastic particles were from Pattani. To conclude, species of crab and site of collection plays a crucial factor in the propensity of plastic particles ingested by the genus Scylla mud crabs.

Coupling of microplastic contamination in organisms and the environment: Evidence from the tidal flat ecosystem of Hangzhou Bay, China

Microplastics are a new type of contaminant, widely defined as fragmented plastics with the longest dimension or diameter less than 5 mm, that are widely distributed, difficult to degrade, and easily adsorb other pollutants. Estuaries are key habitats where terrestrial microplastics flow in water runoff and import into the ocean. The ubiquitous use of plastics has resulted in a massive amount of plastic waste that is released and accumulated in bay ecosystems, posing serious ecological impacts. The study of microplastic contamination in Hangzhou Bay, the estuary of the Qiantang River, has important theoretical value in ecology and environmental science. Microplastic contamination in the tidal flats and organisms of Hangzhou Bay is serious and microplastic characteristics (type, size, and polymer type) in organisms were significantly correlated with those in the environmental media. Spatial autocorrelation was found in the abundance of microplastics in marine and tidal flat sediments of Hangzhou Bay, China, but no spatial autocorrelation was found in the sediment environment as a whole. The microplastic abundance in each organism in this study was not statistically correlated by weight or by individual count with its corresponding trophic level (P = 0.239 > 0.05; P = 0.492 > 0.05, respectively). Our study suggests a coupling relationship of microplastic contamination between organisms and the environment and can provide essential data and a scientific foundation for the study of microplastics pollution in Hangzhou Bay, as well as provide important evidence for the ecological and health risk assessment of microplastics.

Varying abundance of microplastics in tissues associates with different foraging strategies of coastal shorebirds in the Yellow Sea

With the wide application of plastic products, microplastics are now ubiquitous in coastal wetlands, representing a serious threat to the health of coastal organisms. In East Asia, millions of migratory shorebirds depend on the tidal flats of Yellow Sea in China, and they have experienced rapid populations declines due at least partially to the environmental pollution. However, our understanding about the specific exposures and hazards of microplastics, and the factors affecting the bioavailability of microplastics to different shorebird species remains limited, which hinders our ability to address the potential detrimental effects of microplastic accumulation to these fast-disappearing birds. Therefore, this study aims to assess the risk of microplastic exposure in shorebirds, determine the enrichment of microplastics in different tissues, and establish the relationship between shorebirds' foraging strategies and microplastic intake. We extracted and identified microplastics in different tissues sample from the carcasses of 13 individuals in four shorebird species, and measure the abundance, color, size, and roughness of all microplastics found. Microplastics were found in all species except one red-necked stint (Calidris ruficollis). Polyethylene, silicone, polypropylene, and polyurethane were the main polymers identified in shorebirds. Microplastics found in shorebirds that use mixed tactile and visual foraging strategy were smaller, less rough, and low in color diversity, compared to those found in shorebirds that forage predominately using visual cues. In addition, ingested microplastics were disproportionately enriched in different tissues; in particular, the abundance and size of microplastics in the digestive tract were significantly higher than those in the pectoral muscles. Understanding the stress of microplastics posed to coastal shorebirds is critical to facilitate more effective and targeted measurements in coastal pollution control.