First insight into plastics ingestion by fish in the Gulf of California, Mexico

Microplastics in different tissues of historical and live samples of endangered mega-fish (Acipenser sinensis) and their potential relevance to exposure pathways

The Chinese sturgeon (Acipenser sinensis) is an endangered freshwater mega-fish (IUCN-red listed) that survives in the Yangtze River Basin, but the population of which has declined significantly in response to environmental pressures generated by human activities. In order to evaluate the interaction between Chinese sturgeon and microplastics (MPs) for the first time, we examined the gut and gills of historical samples (n = 27), in conjunction with the blood and mucus of live samples (n = 10), to explore the potential pathways involved in MP uptake. We detected MPs in 62.9 % of the field fish, with no significant difference between guts (mean=0.9 items/individual) and gills (mean=0.8 items/individual). The abundance of MPs in fish from 2017 was significantly higher than that from 2015 to 2016 with regards to both gills and gut samples. The size of MPs in gills was significantly smaller than those in guts, yet both contained mostly fibers (90.2 %). No MPs were confirmed in blood, however 62.5 % of mucus samples contained MPs. The MPs in mucus indicated the possibility of MPs entering Chinese sturgeons if their skins were damaged. The body size of Chinese sturgeons affected their MPs uptake by ingestion and inhalation, as less MPs were detected in the gut and gills of smaller individuals. Combining the evidence from historical and live samples, we revealed the presence of MPs in different tissues of Chinese sturgeon and their potential relevance to exposure pathways. Our work expands the understanding of multiple exposure pathways between MPs and long-lived mega-fish, while emphasizing the potential risks of long-term exposure in the field.

First account of microplastics in pelagic sporting dolphinfish from the eastern Mexican coast of Baja California Sur

This study is a baseline data on the presence of MPs from the gastro-intestinal tracts (GITs) in Coryphaena hippurus Linnaeus, from eastern Baja California Sur, México. 878 MPs items (in %) of fibers (29%), fragments (68%) and films (1.3%) were detected from 51 GITs of Coryphaena hippurus. Transparent, white, blue and black were the prevalent colours. Morphological features observed through SEM analysis, the presence of heavily weathered MPs is due to the mechanical, microbiological and chemical weathering process. PP (29%), Nylon (29%), PS (17%), PE (11%), PET (6%) and HDPE (8%) presence indicates their source from regional anthropogenic stress. Trophic level transition is enforced by polymer derivative, permitting the sinking behavior of MPs and increased ingestion probability. Fishes were classified as slim despite their higher feeding capabilities and ingested MPs indicates a relationship with environmental contaminants. Current study emphasizes the health risk linked to biological aspects of MPs ingestion.

Analysis of the community behavioural patterns in management of household plastic waste due to the COVID-19 pandemic in Sri Lanka

The COVID-19 pandemic has adversely affected human lifestyle in numerous ways and one such key affected social element is the management of household plastic waste. Due to its effective barrier properties against the COVID-19 virus, usage and consumption of personal protective equipment (PPE) and other single-use plastic (SUP) products have increased exponentially to meet the accelerated demand. Therefore, this paper analyses the changes in community behavioural patterns of household plastic waste management with the prevailing COVID-19 pandemic situation in Sri Lanka. The comparative analysis of majorly consumed plastic waste types, plastic disposal methods, and perceptions of existing policies before and after the pandemic are broadly discussed. A comprehensive questionnaire was conducted in a stratified randomly sampled community and analysed using SPSS. Disposable face masks (39.9%) and hand sanitiser products (33.0%) were popular plastic products during the pandemic. The frequency of handing over the waste to collectors and recycling centres decreased slightly, from 32.1% to 31.4% and 24.2%-19.8%, respectively. Conversely, respondents' preference for burning plastic waste increased from 23.4% to 27.0% after the pandemic. The plastic disposal methods from before and after the pandemic are significantly associated with income level (p = 0.00) and employment status (p = 0.00). No significant association was observed between the disposal method before the pandemic and the education level of respondents (p = 0.185). However, a significant association was evident between the disposal method after the pandemic and the education level of respondents (p = 0.025).

First report of plastic contamination in batoids: Plastic ingestion by Haller's Round Ray (Urobatis halleri) in the Gulf of California

The presence of microplastics has been reported in the marine environment and these pollutants have also been reported in food webs. Information about the presence of microplastics in the Haller's Round Ray (Urobatis halleri) and bottom sediments off the east coast of the Gulf of California is non-existent. The digestive tracts of individuals of this species and sediment samples were examined for plastic particles in this region. In total, 107 plastic particles were found in the sediment. All were fibers and 94.4% were microplastics, the rest were mesoplastics. The gastrointestinal tracts of 142 rays were analysed, and it was determined that this is a benthic feeder. A total of 386 plastic particles were recovered from 46 individuals (32.4%). On average 10.2 (±7.4) plastic particles were found per specimen, with plastic lengths ranging from 0.00821 mm to 0.953 mm. The FTIR-ATR analysis revealed the presence of six types of polymers: polyamide or nylon polyethylene, polypropylene, and polyacrylic were found in both sediments and gastrointestinal tracts of Haller's Round Ray. Polyethylene terephthalate and polyacrylamide were only found in the gastrointestinal tracts of the ray. These polymers are consistent with the human activities undertaken in this area, specifically intensive small-scale and industrial fisheries, as they are used for the elaboration of fishing nets, plastic bags, storage containers, clothing, and fishing boats maintenance. Our results show that benthic feeders are exposed to plastic debris, and its presence is another potential threat to batoids, which are already threatened by bycatch, overfishing, and other pollutants. However, studies on the ingestion of plastic debris in batoids and its presence in the sediment are still scarce or non-existent for this region. As such, these studies are necessary to help in the preservation of these species.