iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829, Landau, Germany.
Ecotoxicology. 2021 Mar;30(2):213-223. doi: 10.1007/s10646-020-02335-9. Epub 2021 Jan 20.
Amphibian populations are declining worldwide at alarming rates. Among the large variety of contributing stressors, chemical pollutants like pesticides have been identified as a major factor for this decline. Besides direct effects on aquatic and terrestrial amphibian stages, sublethal effects like impairments in reproduction can affect a population. Therefore, we investigated the reproductive capacity of common toads (Bufo bufo) in the pesticide-intensive viticultural landscape of Palatinate in Southwest Germany along a pesticide gradient. In a semi-field study, we captured reproductively active common toad pairs of five breeding ponds with different pesticide contamination level and kept them in a net cage until spawning. Toads from more contaminated ponds showed an increased fecundity (more eggs) but decreased fertilization rates (fewer hatching tadpoles) as well as lower survival rates and reduced size in Gosner stage 25, suggesting that the higher exposed populations suffer from long-term reproductive impairments. In combination with acute toxicity effects, the detected sublethal effects, which are mostly not addressed in the ecological risk assessment of pesticides, pose a serious threat on amphibian populations in agricultural landscapes.
两栖动物种群在全球范围内以惊人的速度减少。在导致这种减少的各种压力因素中，化学污染物如农药已被确定为主要因素之一。除了对水生和陆生两栖动物阶段的直接影响外，亚致死效应如繁殖能力受损也会影响种群。因此，我们沿着农药梯度在德国西南部的普法尔茨州农药密集型葡萄种植区调查了常见蟾蜍（Bufo bufo）的繁殖能力。在一项半野外研究中，我们从五个具有不同农药污染水平的繁殖池塘中捕获了具有繁殖能力的蟾蜍对，并将它们放在一个网笼中，直到产卵。来自污染程度较高池塘的蟾蜍表现出更高的繁殖力（更多的卵），但受精率（孵化的蝌蚪较少）降低，存活率降低，Gosner 阶段 25 的体型减小，这表明暴露程度较高的种群受到长期繁殖障碍的影响。结合急性毒性效应，检测到的亚致死效应（在农药的生态风险评估中大多未涉及）对农业景观中的两栖动物种群构成了严重威胁。
