Pesticide exposure can have negative impacts on many species and is a major threat to biodiversity.
A new study is one of few to assess the risks specifically for European reptiles.
The results suggest that at least one third of European reptile species are at high risk of exposure, with lizards showing the highest sensitivity to pesticides.
Risk of pesticide exposure for reptile species in the European Union, Science Direct, August 2016.
Turtle & frog image by usfwshq.
Environmental pollution has an especially high impact on wildlife. This is especially the case in industrialized countries. Although, many species within the European Union benefit from protection by the Habitats Directive, no special consideration is given to possible detrimental effects of pesticides. This is in particular remarkable as negative effects, which may lead to a regional diversity loss, have already been identified in laboratory and mesocosm studies.
We conducted a pesticide exposure risk evaluation for all European reptile species with sufficient literature data on the considered biological and ecological aspects and occurrence data within agricultural areas with regular pesticide applications (102 out of 141). By using three evaluation factors – (i) pesticide exposure, (ii) physiology and (iii) life history – a taxon-specific pesticide exposure risk factor (ERF) was created. The results suggest that about half of all evaluated species, and thus at least 1/3 of all European species exhibited a high exposure risk. At the same time, two of them (Mauremys leprosa and Testudo graeca) are globally classified as threatened with extinction in the IUCN Red List of Threatened Species. Variation regarding species occurrence in exposed landscapes between pesticide admission zones within the EU is rather large. This variation is mainly caused by differing land use and species abundances between zones. At the taxonomic level, significant differences in exposure risk can be observed between threatened and non-threatened species, which can be explained by the formers remote distribution areas. Lizards display the highest sensitivity toward pesticides, although no differences in overall ERFs can be observed between taxonomic groups.
By identifying species at above-average risk to pesticide exposure, species-based risk evaluations can improve conservation actions for reptiles from cultivated landscapes.