Legacy contaminant trends in the Great Lakes uncovered by the wildlife environmental quality index

M P Hammond; S R de Solla; K D Hughes; M E B Bohannon; K G Drouillard; G C Barrett; W W Bowerman

doi:10.1016/j.envpol.2023.123119

Legacy contaminant trends in the Great Lakes uncovered by the wildlife environmental quality index

Environ Pollut. 2024 Feb 15:343:123119. doi: 10.1016/j.envpol.2023.123119. Epub 2023 Dec 11.

Authors

M P Hammond¹, S R de Solla², K D Hughes³, M E B Bohannon⁴, K G Drouillard⁵, G C Barrett¹, W W Bowerman⁴

Affiliations

¹ Ecotoxicology and Wildlife Health Division, Environment & Climate Change Canada, Burlington, Ontario, L7S 1A1, Canada.
² Ecotoxicology and Wildlife Health Division, Environment & Climate Change Canada, Burlington, Ontario, L7S 1A1, Canada. Electronic address: shane.desolla@ec.gc.ca.
³ Broadwing Biological Consulting, Port Perry, Ontario, L9L 1J9, Canada.
⁴ Department of Environmental Science and Technology, University of Maryland, College Park, MD, 20742, United States.
⁵ Great Lakes Institute for Environmental Research (GLIER), University of Windsor, Windsor, Ontario, N9B 3P4, Canada.

PMID: 38092342
DOI: 10.1016/j.envpol.2023.123119

Abstract

Since the 1970s, wildlife managers have prioritized the recovery of Great Lakes ecosystems from contamination by Persistent Organic Pollutants (POPs). Monitoring and quantifying the region's recovery is challenged by the diversity of legacy contaminants in the environment and the lack of benchmarks for their potential biological effects. We address this gap by introducing the Wildlife Environmental Quality Index (WEQI) based on prior water and sediment quality indices. The tool summarizes, in a single score, the exposure of wildlife to harmful levels of multiple contaminants - with harmful levels set by published guidelines for protecting piscivorous wildlife from biological impacts. We applied the new index to a combined Canadian and American dataset of Herring Gull (Larus argentatus) egg data to elucidate trends in wildlife for eight legacy industrial pollutants and insecticides in the Great Lakes. Environmental quality of the Great Lakes region (as indexed by WEQI) improved by 18% between 2002 and 2017. Improvement came from reductions in both the scope of contamination (the number of guideline-exceeding contaminants) and its amplitude (the average size of guideline exceedances) at bird colonies. But recovery was unequal among lakes, with Lake Erie showing no improvement at one extreme. Weakly- or non-recovering lakes (Erie, Ontario, Huron) were marked by inconsistent improvement in scope and amplitude, likely due to ongoing loading, sediment resuspension and other stressors reported elsewhere. Fast-recovering lakes (Superior and Michigan), meanwhile, improved in both scope and amplitude. Contrasting trends and contaminant profiles (e.g., exceedances of PCBs versus DDTs) highlight the importance of lake-specific management for equalizing recoveries. Lower environmental quality at American than Canadian colonies, particularly in Lake Huron, further suggest uneven success in - and opportunities for - the binational management of wildlife exposure to legacy contaminants.

Keywords: Environmental quality; Great lakes; Herring gull; Monitoring; Organochlorines; Persistent organic pollutants (POPs); Wildlife.

MeSH terms

Animals
Animals, Wild
Charadriiformes*
Ecosystem
Environmental Monitoring
Great Lakes Region
Lakes
Ontario
Water Pollutants, Chemical* / analysis

Substances

Water Pollutants, Chemical