Linking water quality stressors and macroinvertebrate diversity in central Pennsylvania using passive samplers

Macroinvertebrate diversity is a critical indicator of water quality and stream health, with some species particularly sensitive to pollutants being unable to live in impaired surface water bodies, leading to low Index of Biotic Integrity (IBI) scores. While causes of surface water impairment in agriculturally dominated watersheds are often excess sediment or nutrients, emerging contaminants (ECs), such as pharmaceuticals, personal care products, and pesticides may also negatively influence macroinvertebrate diversity. This project aims to identify the ecological influence that multiple abiotic water quality stressors may pose on benthic macroinvertebrate communities. Nine monitoring sites were established in three streams in central Pennsylvania to collect macroinvertebrate assemblages and water quality data for more than 50 contaminants of interest from June to September 2021. Benthic macroinvertebrates were collected in May 2021 following protocols from the Pennsylvania Department of Environmental Protection for wadable, freestone, riffle-run streams to calculate IBI scores and assess community composition. Here, the following three objectives were addressed: (1) quantify occurrence of ECs at the study sites using passive and active water sampling methods; (2) assess the effectiveness of each sampling method to detect a wide range of ECs; and (3) identify the current macroinvertebrate assemblage and understand how current water quality metrics could influence the community assemblage. These data will provide insights on occurrence and temporal variability of multiple water-quality stressors on macroinvertebrate species and community composition. Results will be used to develop controlled mesocosm experiments to better understand the ecotoxicological effects of these contaminants on sensitive macroinvertebrate species.