Egestion rates of microplastic fibres in fish scaled to in situ concentration and fish density
Egestion rates of microplastic fibres in fish scaled to in situ concentration and fish density
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DOI：
10.1111/fwb.14007
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发表时间：
2022-10
影响因子：
2.7
通讯作者：
Loren Hou;R. McNeish;T. Hoellein
中科院分区：
文献类型：
--
作者：
Loren Hou;R. McNeish;T. Hoellein
微塑料(颗粒<；5 mm)普遍存在于不同分类群体和生态系统的水生生物中。然而，水生生物中微塑料的排泄率以及排泄率与环境中其他微塑料移动率的比较鲜有文献记载。我们给罗伦斯五大湖中丰富的入侵物种--圆形虎鱼(Neogobius Melanostomus)喂食了微塑料纤维。我们进行了两个试验，分别一次(1 天)或每天喂食含有微塑料的食物超过7 天。与1 天和7 天喂养试验相比，微塑料排泄率没有差异，表明暴露时间对排泄量没有影响(指数衰减率分别为−0.055[±0.016SE]和 −0.040[±0.007SE])。微塑料在肠道中的周转时间(即从摄食到排出的平均时间)在18.2THr到25.0THr之间，与其他淡水类群的公布值相似。我们还测量了直接从美国密歇根湖采集的圆虎鱼消化道中的微塑料。利用研究地点公布的圆虎鱼密度和微塑料浓度，我们计算了圆虎鱼(No. )的面积排泄率。颗粒 m-2day-1)，并与河水微塑料出口(No.颗粒物 m-2day-1)。这两个基于区域的速率是相同的数量级，这表明圆形虎鱼排放可能是生态系统规模微塑性动力学中一个重要的、但可能被忽视的组成部分。动物排放是众所周知的营养和碳循环的主要组成部分。然而，包括动物排泄率在内的环境中微塑料通量的直接测量是不常见的。需要一种生态系统生态学方法来应对新出现的挑战，即为淡水环境和其他地方产生微塑料预算，从而在全球范围内为塑料污染的管理和缓解提供信息。
Microplastics (particles <5 mm) are commonly found in aquatic organisms across taxonomic groups and ecosystems. However, the egestion rate of microplastics from aquatic organisms and how egestion rates compare to other rates of microplastic movement in the environment are sparsely documented.We fed microplastic fibres to round gobies (Neogobius melanostomus), an abundant, invasive species in the Laurentian Great Lakes. We conducted two trials where round gobies were fed microplastic‐containing food either a single time (1 day) or every day over 7 days.There was no difference in microplastic egestion rates from the 1 day or 7 day feeding trials, suggesting no impact of duration of exposure on egestion (exponential decay rate = −0.055 [±0.016SE] and −0.040 [±0.007SE], respectively). Turnover time of microplastics (i.e., average time from ingestion to egestion) in the gut ranged from 18.2 to 25.0 hr, similar to published values for other freshwater taxa.We also measured microplastics in the digestive tracts of round gobies collected directly from Lake Michigan, U.S.A. Using published values for round goby density and microplastic concentration at the study sites, we calculated areal egestion rate by round gobies (no. particles m–2day–1), and compared it to riverine microplastic export (no. particles m–2day–1). Both area‐based rates were of the same order of magnitude, suggesting that round goby egestion could be an important, and potentially overlooked component of microplastic dynamics at the ecosystem scale.Animal egestion is well‐known as a major component of nutrient and carbon cycling. However, direct measurements of microplastic fluxes in the environment that include animal egestion rates are uncommon. An ecosystem ecology approach is needed to meet the emerging challenge of generating microplastic budgets for freshwater environments and elsewhere, thereby informing management and mitigation of plastic pollution at a global scale.