Abstract：
Microplastic exposure can cause a range of negative effects on the biochemistry, condition and ecology of freshwater fishes depending on aspects of the exposure and the exposed fish. However, fishes are typically exposed to microplastics and additional multiple stressors simultaneously, for which the combined effects are poorly understood and may have important management consequences. Additive effects are those where the combined effect is equal to the sum, antagonistic where combined effects are less than the sum and for synergistic effects the combined effect is greater to the sum of the individual effects. Here, we performed a meta-analysis of studies recording freshwater fish responses to microplastic-stressor exposures to test if interactions were primarily non-additive (synergistic or antagonistic), and factors impacting the net response. Individual responses were classified (antagonistic/additive/synergistic) and the fit of net responses to a null additive model determined for 838 responses (36 studies) split by categorical variables for the microplastic exposure (environmental relevance, interacting stressor, microplastic morphology and response category measured), as well as the exposed fish (lifestage, ecology and family). Most responses were classified as antagonistic (48 %) and additive (34 %), with synergistic effects least frequent (17 %). Net responses fitted null additive models for all levels of interacting stressor, fish family and microplastic morphology. In contrast, net antagonism was present for biochemical responses, embryo lifestages, environmentally relevant microplastic exposures and fish with benthopelagic ecology, while synergism was identified for fishes with demersal ecology. While substantial knowledge gaps remain and are discussed, the data thus far suggest microplastic-stressor responses in freshwater fishes are rarely synergistic and, therefore, addressing either or both stressors will likely result in positive management and biological outcomes.
摘要：
微塑料暴露会对生物化学产生一系列负面影响，淡水鱼的状况和生态取决于暴露和暴露鱼类的各个方面。然而,鱼类通常同时暴露于微塑料和额外的多种压力源，对其综合效应知之甚少，可能会产生重要的管理后果。加性效应是指组合效应等于总和的效应，拮抗作用，其中联合作用小于总和，对于协同作用，联合作用大于个体作用的总和。这里,我们对记录淡水鱼对微塑料应激源暴露的反应的研究进行了荟萃分析，以测试相互作用是否主要是非加性的（协同或拮抗），以及影响净响应的因素。对个体反应进行分类（拮抗/加性/协同），并将净反应与针对838项反应（36项研究）确定的零加性模型的拟合度除以微塑料暴露的分类变量（环境相关性，相互作用的压力源，测量的微塑性形态和响应类别)，以及暴露的鱼(生活年龄，生态和家庭)。大多数反应分为拮抗性(48%)和加性(34%)，协同效应最少(17%)。净响应拟合了所有水平的相互作用压力源的零加性模型，鱼类家族和微塑料形态。相比之下,生化反应存在净拮抗作用，胚胎生命，与环境相关的微塑料暴露和具有底栖生态的鱼类，同时确定了具有底层生态的鱼类的协同作用。虽然巨大的知识差距仍然存在，并进行了讨论，迄今为止的数据表明，淡水鱼中的微塑料应激源反应很少是协同的，因此,解决其中一个或两个压力源可能会导致积极的管理和生物学结果。
