Microplastics represent an emerging threat to aquatic environments and organisms, as they infiltrate water systems, are ingested by marine species, and cause physical harm, endocrine disruption, and bioaccumulation up the food chain, potentially impacting biodiversity and human health. Aquatic ecosystems face considerable harm from microplastic pollution because fish in the early developmental stages, including embryos, larvae, and juveniles, are more susceptible due to their immature physiological and detoxification systems. This review aims to comprehensively explore the impacts of microplastics on the early life stages of fish. Aquatic environments receive primary and secondary MPs from urban runoff and industrial waste, together with degraded plastics, which affect fish embryos and larvae via direct ingestion, surface adhesion, and trophic transmission pathways. The physical impact of MPs causes digestive tract blockages that reduce hatching success and create developmental problems in fish organs, but chemical toxicity develops from plasticizers, heavy metal leaching, and pollutant adsorption, which causes oxidative stress, endocrine disruption, and metabolic dysfunction. Survival rates decrease because exposure causes fish to perform poorly during swimming activities and make limited efforts to avoid predators. The small dimensions and high chemical reactivity of MPs increase their bioavailability, which promotes tissue penetration and leads to accumulation at different levels of the food chain. This comprehensive review emphasizes that we need to establish uniform detection protocols, long-term exposure research, and effective strategies to control MP pollution. The resolution of these difficulties remains essential for protecting fish populations, as well as for protecting biodiversity and minimizing seafood contamination risks to human health.

Quinolone antibiotic (QA) residues in various natural environments have recently received massive scientific attention. Nevertheless, there is limited information on the distribution characteristics and potential hazards of antibiotics in coastal wetlands. Here, the occurrence, spatial and seasonal distribution, and ecological risk assessment of eight QAs including pipemidic acid (PPA), ofloxacin (OFL), enrofloxacin (ENR), ciprofloxacin (CIP), sarafloxacin (SAL), lomefloxacin (LOM), flumequine (FLU), and oxolinic acid (OA) in coastal wetland were investigated through collected water, sediment, benthos, and plant samples along the Jiangsu coastline in four seasons. The results demonstrated that all selected QAs were detected with varying frequencies and degrees, and their mean concentrations in water, sediment, plants, and benthos ranged from n.d. to 6.11 ng L⁻¹, 3.10 μg kg⁻¹, 6.14 μg kg⁻¹, and 17.13 μg kg⁻¹, respectively. The seasonal differences in antibiotic concentration indicated higher values in winter and significantly lower values in summer, while no significant variations were observed between spring and autumn. Based on the risk quotient (RQ) method, the ecological risk assessment revealed medium risks for OFL, ENR, CIP, and LOM, and low or no risks of other QAs. It is suggested that the differences in PNEC values between seasons and toxicity of antibiotic mixtures should be considered in future studies for better illustration of actual risk levels. This research provides fundamental data and an assessment pattern that governments and other scientific groups all over the world could use as reference to evaluate QA residues in coastal wetlands.