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The University of Massachusetts Amherst

Rating impacts in a multi-stressor world: a quantitative assessment of 50 stressors affecting the Great Lakes

Authors:

Sigrid Smith

Peter McIntyre

Benjamin Halpern

Roger Cooke

Adrienne Marino

Gregory Boyer

Andy Buchsbaum

G. Burton

Linda Campbell

Jan Ciborowski

Patrick Doran

Dana Infante

Lucinda Johnson

Jennifer Read

Joan Rose

Edward Rutherford

Alan Steinman

David Allan

Publication Type:
Journal Article
Year of Publication:
2015
Secondary Title:
Ecological Applications
ISSN:
1051-0761
DOI:
10.1890/14-0366.1.sm
Pages:
717-728
Volume:
25
Year:
2015
Date:
04-Aug-2015
URL:
https://figshare.com/collections/Rating_impacts_in_a_multi-stressor_world_a_quantitative_assessment_of_50_stressors_affecting_the_Great_Lakes/3296780

Abstract

Ecosystems often experience multiple environmental stressors simultaneously that can differ widely in their pathways and strengths of impact. Differences in the relative impact of environmental stressors can guide restoration and management prioritization, but few studies have empirically assessed a comprehensive suite of stressors acting on a given ecosystem. To fill this gap in the Laurentian Great Lakes, where considerable restoration investments are currently underway, we used expert elicitation via a detailed online survey to develop ratings of the relative impacts of 50 potential stressors. Highlighting the multiplicity of stressors in this system, experts assessed all 50 stressors as having some impact on ecosystem condition, but ratings differed greatly among stressors. Individual stressors related to invasive and nuisance species (e.g., dreissenid mussels and ballast invasion risk) and climate change were assessed as having the greatest potential impacts. These results mark a shift away from the longstanding emphasis on nonpoint phosphorus and persistent bioaccumulative toxic substances in the Great Lakes. Differences in impact ratings among lakes and ecosystem zones were weak, and experts exhibited surprisingly high levels of agreement on the relative impacts of most stressors. Our results provide a basin-wide, quantitative summary of expert opinion on the present-day influence of all major Great Lakes stressors. The resulting ratings can facilitate prioritizing stressors to achieve management objectives in a given location, as well as providing a baseline for future stressor impact assessments in the Great Lakes and elsewhere.