Do Endemic Soil Fauna Species Deserve Extra Protection for Adverse Heavy Metal Conditions?

Abstract

The concept of Ecotoxicological Species Sensitivity Distributions, as used in EU and US, to derive environmental standards for contaminants, starts from the assumption that by protecting the majority of species (95% confidence interval) all species will be protected. Nevertheless, 5% of the species outside the confidence interval might become harmed; half of it being the most sensitive for the particular compound tested. With respect to protection of rare endemic species it is not clear, however, if contamination is a driving factor for endemicity. The aim of this paper is to explore whether endemic and rare species deserve extra protection from adverse environmental conditions. To this end, a brief overview of the various forms of endemism, their relation to environmental stress factors and the distribution of endemic species is discussed. Further, the sensitivities of these species towards environmental stress factors are analysed, in order to conclude if and how endemic species could be better protected against environmental stress factors. This was achieved by specifically focusing on the potential impacts of metalliferous soils, mining, the treatment of mined soil and the storage of treated mine waste. It is concluded that at present there are some signals about specific sensitivities, but the database is much too small for a definite conclusion about adverse environmental factors as a threat to endemic species. The data gap has to be filled in with experimental tests with endemic species. This is hampered by the protection status of these endemic, rare species. Recommendations and derived activities are proposed to address this.