Abstract：
Plastic particles have emerged as a growing threat to both ecosystems and human well-being, as they are being ingested and accumulate at different trophic levels. However, microplastic and mesoplastic contamination and its risk to coastal and marine water fish have not been well studied, particularly in the northern Bay of Bengal. In this study, the presence of small-scale plastic particles (micro- and meso-sized) in the gastrointestinal tract (GIT) and muscles of six edible fish species from the northern Bay of Bengal Coast were identified and analyzed. The overall range of microplastics was 1.74 ± 0.23-3.79 ± 2.03items/g in muscle and 0.54 ± 0.22-5.96 ± 3.16 items/g in the GIT, with 16.38 ± 8.08-31.88 ± 12.09 items/individual. No mesoplastics were found in muscle tissue, but they were present in the GIT at concentrations ranging from 0.33 ± 0.27 to 0.03 ± 0.02 items/g and from 0.51 ± 0.05to 1.38 ± 1.01 items/individual. Lepturacanthus savala accumulated the most microplastics in muscle, and Harpadon nehereus had the least. In addition, the highest levels of mesoplastics were detected in the GIT of Polynemus paradiseus and the lowest was detected in the GIT of Lutjenus sanguineus. Omnivorous fish showed higher plastic concentrations than carnivorous fish, which was linked to dietary habits, feeding strategies and digestive processes. Plastic material predominantly accumulated in the GIT rather than in the muscle. The majority of ingested plastic particles were fibres (95.18 %), were violet in color (34 %), and were < 0.5 mm in size (87 %). The dominant microplastic polymers included 38 % PE, 15 % PP, 33 % PU, and 14 % CES. In contrast, the prevalent mesoplastic polymers comprised 45 % PE, 19 % PP, 13 % PS, 16 % PA, and 7 % PET. Subsequently, a hazard analysis using the polymer hazard index (PHI) revealed that plastic contamination was of distinct hazard categories for different polymer types, ranging from grade I (<1) to grade IV (100-1000). The assessment of the contamination factor (1 < CF < 3) and pollution load index (PLI > 1) indicated moderate contamination of fish by the ingestion of plastic debris. This study provides the foremost evidence for the presence of mesoplastics and microplastics in coastal and marine fish in the study region, paving the way for future investigations and policy implementation.
摘要：
塑料颗粒已经成为对生态系统和人类福祉日益增长的威胁，当它们被摄入并在不同的营养水平积累时。然而,微塑料和中塑污染及其对沿海和海水鱼类的风险尚未得到很好的研究，特别是在孟加拉湾北部。在这项研究中,鉴定并分析了孟加拉湾北部6种可食用鱼类的胃肠道（GIT）和肌肉中存在的小型塑料颗粒（微型和中观大小）。肌肉微塑料的总体范围为1.74±0.23-3.79±2.03项目/g，GIT为0.54±0.22-5.96±3.16项目/g，16.38±8.08-31.88±12.09项/个。在肌肉组织中没有发现介体,但是它们在GIT中的浓度范围为0.33±0.27至0.03±0.02个项目/g和0.51±0.05至1.38±1.01个项目/个。Lepturanthussavala在肌肉中积累了最多的微塑料，HarpadonNetherus吃得最少.此外,在Parademus的GIT中检测到最高水平的介晶塑料，在Lutjenussanguineus的GIT中检测到最低水平。杂食性鱼类显示出比肉食性鱼类更高的塑料浓度，这与饮食习惯有关，喂养策略和消化过程。塑料材料主要积累在GIT中而不是肌肉中。大多数摄入的塑料颗粒是纤维(95.18%)，呈紫色(34%)，尺寸<0.5毫米(87%)。主要的微塑料聚合物包括38％的PE，15%PP,33%PU,和14%的CES。相比之下,普遍的中塑聚合物包含45%的PE，19%PP,13%PS,16%PA,和7%的PET。随后，使用聚合物危害指数（PHI）进行的危害分析显示，塑料污染对于不同的聚合物类型具有不同的危害类别，从I级（<1）到IV级（100-1000）。对污染因子（11）的评估表明，摄入塑料碎片会对鱼类造成中度污染。这项研究为研究区域的沿海和海洋鱼类中存在中塑料和微塑料提供了最重要的证据，为未来的调查和政策实施铺平道路。
