Protectiveness of species sensitivity distribution hazard concentrations for acute toxicity used in endangered species risk assessment

Abstract

A primary objective of threatened and endangered species conservation is to ensure that chemical contaminants and other stressors do not adversely affect listed species. Assessments of the ecological risks of chemical exposures to listed species often rely on the use of surrogate species, safety factors, and species sensitivity distributions (SSDs) of chemical toxicity; however, the protectiveness of these approaches can be uncertain. We comprehensively evaluated the protectiveness of SSD first and fifth percentile hazard concentrations (HC1, HC5) relative to the application of safety factors using 68 SSDs generated from 1,482 acute (lethal concentration of 50%, or LC50) toxicity records for 291 species, including 24 endangered species (20 fish, four mussels). The SSD HC5s and HCls were lower than 97 and 99.5% of all endangered species mean acute LC50s, respectively. The HC5s were significantly less than the concentrations derived from applying safety factors of 5 and 10 to rainbow trout (Oncorhynchus mykiss) toxicity data, and the HCls were generally lower than the concentrations derived from a safety factor of 100 applied to rainbow trout toxicity values. Comparison of relative sensitivity (SSD percentiles) of broad taxonomic groups showed that crustaceans were generally the most sensitive taxa and taxa sensitivity was related to chemical mechanism of action. Comparison of relative sensitivity of narrow fish taxonomic groups showed that standard test fish species were generally less sensitive than salmonids and listed fish. We recommend the use of SSDs as a distribution-based risk assessment approach that is generally protective of listed species.

Comparison ofin silicomodels for prediction ofDaphnia magnaacute toxicity

“…In the same study, compilation and analysis of experimental values indicated that intraspecific variability could be a significant source of uncertainty in species sensitivity distribution (SSD). In another study, experimental Daphnia acute toxicity figures varied by up to 60-fold for the 10 evaluated chemicals, and even highly standardized datasets showed greater than 10-fold differences [26]. In our test set, we noticed a similar situation: experimental acute toxicity values in our test set varied …”

Traits‐based approaches in bioassessment and ecological risk assessment: Strengths, weaknesses, opportunities and threats

“…Recently, interspecies correlation estimates (ICE) have been used to predict toxicities of nontested invertebrates and fish with great accuracy. ICE may become especially valuable because it provides a prognostic tool to obtain a suite of taxa sensitivities that have different physiological and ecological traits (Dyer et al 2006Raimondo et al 2008).…”

A list of fish species that are potentially exposed to pesticides in edge-of-field water bodies in the European Union—a first step towards identifying vulnerable representatives for risk assessment

“…For example, ERA for birds and mammals extrapolate toxicity data for rats or quails (standard test species) to voles and sky larks (focal species) by the use of assessment factors. Other approaches are also available for this extrapolation, such as species sensitivity distributions (Newman et al 2000, Raimondo et al 2008) and interspecies correlation estimation (Raimondo et al 2010). It may also be possible to predict the intrinsic sensitivities of specific fish to a toxicant by combining toxicokinetic–toxicodynamic models (Ashauer and Escher 2010, Stadnicka et al 2012) and in vitro screening techniques (Segner et al 2003).…”