Quantifying sublethal effects of plastics ingestion on marine wildlife is difficult, but key to understanding the ontogeny and population dynamics of affected species. We developed a method that overcomes the difficulties by modelling individual ontogeny under reduced energy intake and expenditure caused by debris ingestion. The predicted ontogeny is combined with a population dynamics model to identify ecological breakpoints: cessation of reproduction or negative population growth. Exemplifying this approach on loggerhead turtles, we find that between 3% and 25% of plastics in digestive contents causes a 2.5–20% reduction in perceived food abundance and total available energy, resulting in a 10–15% lower condition index and 10% to 88% lower total seasonal reproductive output compared to unaffected turtles. The reported plastics ingestion is insufficient to impede sexual maturation, but population declines are possible. The method is readily applicable to other species impacted by debris ingestion.

中文翻译：

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量化塑料碎片对海洋野生动植物的影响可以确定生态断点。

量化塑料摄入对海洋野生动植物的亚致死作用是困难的，但这是了解受影响物种的个体发育和种群动态的关键。我们开发了一种方法，该方法通过在减少由碎片摄入引起的能量摄入和消耗的情况下对个体个体进行建模来克服困难。预测的个体发育与种群动态模型相结合，以识别生态断点：繁殖停止或种群负增长。以这种在on龟上的方法为例，我们发现消化成分中3％至25％的塑料会使感知的食物丰度和总可用能量降低2.5–20％，从而使状况指数降低10–15％，降低10％与未受影响的海龟相比，季节性繁殖总产量降低了88％。报道的塑料摄入不足以阻止性成熟，但是人口下降是可能的。该方法可容易地应用于受碎片吞噬影响的其他物种。