Table1_An enigma: A meta-analysis reveals the effect of ubiquitous microplastics on different taxa in aquatic systems.docx

Microplastics are ubiquitous in aquatic ecosystems globally, with tropical freshwater systems underrepresented in the literature. The ubiquity of microplastics may affect the feeding, growth, reproduction, and survival of organisms in aquatic systems; however, the data on the potential effects of microplastics on aquatic organisms is tentative. In the current study, I conducted a meta-analysis using published data to examine the impacts of microplastic exposure on functional traits (i.e., feeding, growth, reproduction, survival) of fish and aquatic invertebrates. The data revealed that while there were within-taxa negative effects on traits such as reproduction and growth some effect sizes were low, suggesting that the exposure to microplastics may vary across taxa. Globally, negative effects on growth, reproduction, and even survival were evident in some taxa (e.g., bivalves, crustaceans). Considering feeding habits, negative effects of microplastic were more pronounced in bacterivores, omnivores, predators, and filter feeders compared to shredders. In tropical freshwater systems, microplastics had no significant effects on the feeding, growth, reproduction, and survival of aquatic organisms. It is worth noting that organisms that are passive feeders (e.g., bivalves) may be particularly susceptible to microplastic pollution, which in turn may have long-lasting effects on the stability of lacustrine and lotic food webs. Because microplastics may impart more chronic effects than acute effects, future works must include understudied regions of the world (e.g., freshwater systems) and must emphasize the subtle role that microplastics may play on the physiology and behavior of organisms in the long term.

全球范围内，微塑料在水生生态系统中普遍存在，而热带淡水系统在文献中却鲜有涉及。微塑料的普遍性可能影响水生系统中生物的摄食、生长、繁殖和生存；然而，关于微塑料对水生生物潜在影响的数据尚属初步。在本研究中，我通过对已发表数据的元分析，探讨了微塑料暴露对鱼类和水生无脊椎动物功能特性（即摄食、生长、繁殖、生存）的影响。数据显示，尽管某些物种（如繁殖和生长）在物种内部存在负面的影响，但某些效应量较低，表明微塑料的暴露可能在不同物种之间存在差异。在全球范围内，一些物种（如双壳类、甲壳类）在生长、繁殖甚至生存方面出现了负面效应。考虑到摄食习性，与食屑动物相比，微塑料对细菌食性动物、杂食性动物、捕食者和滤食动物的负面影响更为显著。在热带淡水系统中，微塑料对水生生物的摄食、生长、繁殖和生存没有产生显著影响。值得注意的是，被动摄食的生物（如双壳类）可能对微塑料污染尤为敏感，这反过来可能对湖泊和河流食物网的稳定性产生持久影响。鉴于微塑料可能产生的慢性效应比急性效应更为严重，未来的研究必须包括世界上的研究较少的区域（如淡水系统），并强调微塑料在长期内对生物生理和行为中所扮演的微妙角色。