To Split or Not to Split: Characterizing Chemical Pollution Impacts in Aquatic Ecosystems with Species Sensitivity Distributions for Specific Taxonomic Groups

Bridging applied ecology and ecotoxicology is key to
protect ecosystems.
These disciplines show a mismatch, especially when evaluating pressures.
Contrasting to applied ecology, ecotoxicological impacts are often
characterized for whole species assemblages based on Species Sensitivity
Distributions (SSDs). SSDs are statistical models describing per chemical
across-species sensitivity variation based on laboratory toxicity
tests. To assist in the aligning of the disciplines and improve decision-support
uses of SSDs, we investigate taxonomic-group-specific SSDs for algae/cyanobacteria/aquatic
plants, invertebrates, and vertebrates for 180 chemicals with sufficient
test data. We show that splitting improves pollution impact assessments
for chemicals with a specific mode of action and, surprisingly, for
narcotic chemicals. We provide a framework for splitting SSDs that
can be applied to serve in environmental protection, life cycle assessment,
and management of freshwater ecosystems. We illustrate that using
split SSDs has potentially large implications for the decision-support
of SSD-based outputs around the globe.