Can road stormwater ponds be successfully exploited by the European green frog (Pelophylax sp.)?

Abstract

Stormwater ponds ("SWPs") are artificial roadside structures, conceived to retain and clean polluted runoff water, before its release to the environment. SWPs were not designed as suitable habitats for wildlife. However, SWPs in Europe are frequently used as breeding sites by amphibians, especially by the European green frog (Pelophylax sp.). Yet, the potential longterm effects of pollutants within SWPs on the populations of this species are unknown. In this study, we investigated the suitability of SWPs as a habitat for European green frogs living in Alsace, NE France, a region with a highly modified landscape that mainly consists of croplands with few natural wetlands remaining. We compared various biological indicators of individual health in 709 green frogs belonging to different life history stages, living in 9 semi-natural ponds (SNPs) and in 25 SWPs. There were no differences between these two pond types for most of the indicators investigated. However, juveniles had a lower body condition (-124%) in SWPs, while adults were 8.3% larger and 41.4% heavier in SWPs. Based on these results, we suggest that SWPs are not a suitable habitat for the development of European green frogs (i.e. juveniles), but may serve as a substitute habitat for adults in a highly modified landscape with few natural wetlands remaining. SWPs may especially act as relay sites, allowing frogs to colonize relict wetlands.

Understanding the role of biodiversity in the climate, food, water, energy, transport and health nexus in Europe

“…The negative influences of transport on biodiversity are mainly due to the infrastructure. Roads cause habitat fragmentation and loss (Conan et al, 2022; and affect species richness. Road density and proximity negatively impact amphibian species richness (Bounas et al, 2020;.…”

“…Road construction and off-road driving for forest management can increase sediment loading, stream network fragmentation, and flood frequency in water bodies nearby (Kuglerová et al, 2021). Road traffic pollutes stormwater (Conan et al, 2022;Sun et al, 2019) and nearby water bodies, for example, with de-icing salts and sediments, brake linings and tires, and runoff containing the byproducts of petroleum and diesel combustion, which affect aquatic organisms (Grung et al, 2021;Nava et al, 2020;Niedrist et al, 2021;Šigutová et al, 2022;Sun et al, 2018Sun et al, , 2019. Sinkhole ponds along the roadsides can also contain higher salinity and concentrations of calcium and phosphates (Krodkiewska et al, 2019).…”