A meta-analysis of the characterisations of plastic ingested by fish globally

Plastic contamination in the environment is common but the characterisation of plastic ingested by fishes in different environment is lacking. Hence, a meta-analysis was conducted to identify the prevalence of plastic ingested by fish globally. Based on the qualitative analysis of plastic size, small microplastic (<1 mm) was predominantly ingested by fish globally. Besides, our meta-analysis revealed that plastic fibres (70.6%) and fragments (19.3%) were the most prevalent plastic components ingested by fish, while blue (24.2%) and black (18.0%) coloured plastic were the most abundant. Polyethylene (15.7%) and polyester (11.6%) were the most abundant polymers. Mixed-effect models were employed to identify the effects of the moderators (sampling environment, plastic size, digestive organs examined, and sampling continents) on the prevalence of plastic shape, colour, and polymer type. Among the moderators, only the sampling environment and continent contributed to a significant difference between subgroups in plastic shape and polymer type. The result suggested that most of the fish species ingested plastic unintentionally due to its prevalence in the environment.环境塑料污染已较为普遍，但目前针对不同生境中鱼类摄食塑料的特征解析研究仍较为匮乏。为此，本研究开展荟萃分析（meta-analysis），以探明全球范围内鱼类摄食塑料的流行率。通过对塑料粒径的定性分析发现，全球范围内鱼类主要摄食粒径小于1毫米的小型微塑料（microplastic）。此外，本次荟萃分析结果显示，鱼类摄食的塑料组分中，纤维状塑料（70.6%）与碎片状塑料（19.3%）占比最高；颜色维度上，蓝色塑料（24.2%）与黑色塑料（18.0%）最为常见。聚合物类型方面，聚乙烯（Polyethylene，15.7%）与聚酯（Polyester，11.6%）占比最高。本研究采用混合效应模型（mixed-effect models），分析调节变量（采样生境、塑料粒径、检测消化器官及采样大洲）对塑料形态、颜色及聚合物类型流行率的影响。在所有调节变量中，仅采样生境与采样大洲可导致鱼类摄食塑料的形态及聚合物类型亚组间存在显著差异。研究结果表明，由于环境中塑料污染广泛分布，绝大多数鱼类均为无意摄食塑料。