The occurrence, speciation, and ecological effect of plastic pollution in the bay ecosystems

Effects of microplastics on sedimentary greenhouse gas emissions and underlying microbiome-mediated mechanisms: A comparison of sediments from distinct altitudes

Microplastics (MPs) are emerging contaminants in aquatic ecosystems that can profoundly affect carbon and nitrogen cycling. However, the impact mechanisms of MPs on sedimentary greenhouse gas (GHG) emissions at distinct altitudes remain poorly elucidated. Here, we investigated the effects of polyvinyl chloride (PVC) and polylactic acid (PLA) on sedimentary CO2, CH4, and N2O emissions at distinct altitudes of the Yellow River. PVC increased the relative abundance of denitrifiers (e.g., Xanthobacteriaceae, Rhodocyclaceae) to promote N2O emissions, whereas PLA reduced the abundance of AOA gene and denitrifiers (e.g., Pseudomonadaceae, Sphingomonadaceae), impeding N2O emissions. Both PVC and PLA stimulated the growth of microbes (Saprospiraceae, Aquabacterium, and Desulfuromonadia) associated with complex organics degradation, leading to increased CO2 emissions. Notably, the concurrent inhibition of PLA on mcrA and pmoA genes led to its minimal impact on CH4 emissions. High-altitude MQ sediments, characterized by abundant substrate and a higher abundance of functional genes (AOA, AOB, nirK, mcrA), demonstrated higher GHG emissions. Conversely, lower microbial diversity rendered the low-altitude LJ microbial community more susceptible to PVC, leading to a more significant promotion on GHG emissions. This study unequivocally confirms that MPs exacerbate GHG emissions via microbiome-mediated mechanisms, providing a robust theoretical foundation for microplastic control to mitigate global warming.

The role of Geographic Information Systems in mitigating plastics pollution in the Global South-A spatial analysis of recycling facilities in Costa Rica

Costa Rica is at the forefront of environmental conservation in Central America, with its focus on sustainability and green practices. Building on this foundation, the country joins a cohort of middle-income developing countries that have set forth ambitious goals to eliminate plastic pollution and become plastics-free. Recycling remains one of the most effective ways of removing plastic waste from the environment. Although GIS has been utilized in environmental research, its use is still expanding in developing countries of the Global South. These countries are experiencing unprecedented adverse climate and ecological impacts while also pursuing fundamental socioeconomic growth. The application of more cost-effective and strategic technological solutions, as well as data-driven decision-making, could fast-track the achievement of their urgent environmental goals. Using Geographic Information Systems (GIS) analysis, this study applies hot spot, location-allocation, and time-distance measures to examine Costa Rica's capacity to recycle plastic waste. Focusing specifically on availability and the public's access to recycling facilities, this article offers insights into the resource constraints and evolution of plastics governance in developing countries with environmentally-focused priorities. The findings of this study suggest that while Costa Rica is implementing progressive plastics regulatory policies, the ability to achieve plastics-free status is hampered by shortfalls in the number and distribution of recycling facilities and the public's access to recycling services. Expanding recycling infrastructure, including transportation, and adopting a less canton-centric waste administration system could contribute to resolving these challenges. This study contributes to discourses on global plastics governance and environmental change management in the Global South.

Environmental occurrence and ecotoxicity of aquaculture-derived plastic leachates

Plastic products such as fishing nets and foam buoys have been widely used in aquaculture. To enhance the desirable characteristics of the final equipment, plastic gear for aquaculture is mixed with a wide range of additives. Recent studies have shown that additives could be leached out to the environment with a long-term use of aquaculture plastics, forming aquaculture-derived plastic leachates. It should be emphasized that some leachates such as phthalic acid esters (PAEs) and organophosphate esters (OPEs) are endocrine disruptors, which could increase the exposure risk of aquatic products and subsequently display potential threats to human health via food chain. However, systematic studies on the release, occurrence, bioaccumulation, and toxic effects of aquaculture-derived plastic leachates are missing, overlooking their potential sources and ecotoxicological risks in aquatic environments. We have reviewed and compared the concentrations of major plastic leachates in the water environment and organisms of global aquaculture and non-farmed areas, confirming that aquaculture leachate is an important source of contaminants in the environment. Moreover, the toxic effects of aquaculture-derived plastic additives and the related mechanisms are summarized with fish as a representative, revealing their potential health risk. In addition, we proposed current challenges and future research needs, which provides scientific guidance for the use and management of plastic products in aquaculture industries.

Is Wild Marine Biota Affected by Microplastics?

The present review provides detailed information on the adverse effects of MPs on wild marine organisms, including tissue damage, fish condition, oxidative stress, immune toxicity, and genotoxicity. A bibliometric analysis was carried out on CiteSpace (version 6.1.R3) (Drexel University, Philadelphia, PA, USA) to verify how many papers studied the effects on wild marine species. The results showed a total of 395 articles, but only 22 really presented data on the effects or impacts on marine biota, and of these, only 12 articles highlighted negative effects. This review shows that the observed effects in wild organisms were less severe and milder than those found in the experimental conditions. The knowledge of negative effects caused by direct ingestion of microplastics in wild animals is still limited; more efforts are necessary to fully understand the role of MPs and the adverse effects on wild marine organisms, the ecosystem, and human health.