CNRS, IPHC UMR 7178, Université de Strasbourg, 67000, Strasbourg, France.
Collectivité Européenne d'Alsace, CERISE, Place du Quartier Blanc, 67964, Cedex 9, Strasbourg, France.
Environ Sci Pollut Res Int. 2023 Jan;30(5):12114-12124. doi: 10.1007/s11356-022-22991-0. Epub 2022 Sep 14.
Stormwater ponds (SWPs) are built to collect and retain polluted runoff water from roads. Consequently, they are not perceived as suitable habitat for wetland species, such as many amphibians. However, given the drastic decline of wetland areas, SWPs may serve as a habitat for protected amphibian species, such as the European green toad (Bufotes viridis). The latter species is frequently found inside these artificial ponds, but their reproductive success is unknown. We assessed the suitability of SWPs as breeding habitat for European green toads by monitoring 8 SWPs and 8 semi-natural ponds (SNPs), which served as control sites. At each site, two groups of 30 tadpoles, originating at that site, were held inside two floating enclosures that contained sediment from the respective pond. During bi-weekly monitoring, tadpoles were counted and measured, allowing to estimate growth and mortality rates. A variety of biotic and abiotic factors were studied to determine the causes of potential differences in growth and mortality rates between the two pond types. While growth rate did not differ between pond types, mortality rates were significantly greater in SWPs than in SNPs. The extremely low survival rate observed in SWPs might be explained by the considerably greater pollutant concentration in their sediment and/or by the presence of leeches, which were found exclusively inside SWPs. Implementation of management measures, such as regular draining/dredging during winter, might help to lower the pollutant concentration in the sediment and reduce the density of leeches inside SWPs, improving their suitability as habitat for amphibians.
雨水池塘（SWP）用于收集和滞留道路上受污染的径流。因此，它们通常不被认为是适合湿地物种的栖息地，如许多两栖动物。然而，鉴于湿地面积的急剧减少，SWP 可能成为受保护的两栖物种的栖息地，如欧洲绿蟾蜍（Bufotes viridis）。后者经常在这些人工池塘中发现，但它们的繁殖成功率未知。我们通过监测 8 个 SWP 和 8 个半自然池塘（SNP）来评估 SWP 作为欧洲绿蟾蜍繁殖栖息地的适宜性，这些池塘作为对照点。在每个地点，两组 30 只蝌蚪，分别来自于该地点，被放置在两个包含各自池塘沉积物的漂浮围栏中。在每两周的监测期间，计算并测量了蝌蚪的数量，以估计生长和死亡率。研究了各种生物和非生物因素，以确定两种池塘类型之间生长和死亡率差异的潜在原因。虽然生长率在池塘类型之间没有差异，但 SWP 中的死亡率明显高于 SNP。SWP 中观察到的极低存活率可能是由于其沉积物中污染物浓度较高和/或由于仅在 SWP 中发现的水蛭的存在造成的。实施管理措施，如冬季定期排水/疏浚，可能有助于降低沉积物中的污染物浓度，并减少 SWP 中水蛭的密度，从而提高其作为两栖动物栖息地的适宜性。
