An expanded fish-based index of biotic integrity for Great Lakes coastal wetlands

Abstract

Biotic indicators are useful for assessing ecosystem health because the structure of resident communities generally reflects abiotic conditions integrated over time. We used fish data collected over 5 years for 470 Great Lakes coastal wetlands to develop multi-metric indices of biotic integrity (IBI). Sampling and IBI development were stratified by vegetation type within each wetland to account for differences in physical habitat. Metrics were evaluated against numerous indices of anthropogenic disturbance derived from water quality and surrounding land-cover variables. Separate datasets were used for IBI development and testing. IBIs were composed of 10–11 metrics for each of four vegetation types (bulrush, cattail, water lily, and submersed aquatic vegetation). Scores of all IBIs correlated well with disturbance indices using the development data, and the accuracy of our IBIs was validated using the testing data. Our fish IBIs can be used to prioritize wetland protection and restoration efforts across the Great Lakes basin. The IBIs will also be useful in monitoring programs mandated by the Agreement between Canada and the United States of America on Great Lakes Water Quality, such as for assessing Beneficial Use Impairments (BUIs) in Great Lakes Areas of Concern, and in other ecosystem management programs in Canada and the USA.

A Basin-Wide Survey of Coastal Wetlands of the Laurentian Great Lakes: Development and Comparison of Water Quality Indices

“…In our survey, which encompasses the largest number of Great Lakes coastal wetlands surveyed to date and is comprised of wetlands along both the U.S. and Canadian shorelines, we revealed patterns of coastal wetland water quality associated with land use and land cover alterations that complement previous studies. Such water quality impairments have been associated with changes to biological communities inhabiting Great Lakes coastal wetlands, including macrophytes (Lougheed et al 2001;Croft and Chow-Fraser 2007), macroinvertebrates Cooper et al 2007), and fishes (Uzarski et al 2005;Seilheimer and Chow-Fraser 2006;Cooper et al 2018). A focus on improving water quality in coastal wetlands is vital to enhance habitat for biota and reduce pollution loads to open-water habitats of the Great Lakes.…”

“…Although acute disturbances such as pulses of point-source contaminant discharge may not be detectable over long periods, chronic anthropogenic disturbances (e.g., increased nutrient and sediment loadings that accompany agricultural land use and urban development) have been associated with altered water quality across Great Lakes coastal wetlands (Chow-Fraser 2006;Morrice et al 2008). These anthropogenic disturbances also influence the scores of macroinvertebrate-and fish-based IBIs within Great Lakes coastal wetlands (Uzarski et al , 2005Cooper et al 2018).…”

Leveraging a Landscape-Level Monitoring and Assessment Program for Developing Resilient Shorelines throughout the Laurentian Great Lakes

“…More recently, fish have been used to assess wetland condition. Recognition of the importance of coastal wetlands to Great Lakes fishes (e.g., Jude and Pappas 1992 ) initiated a movement toward using fishes as indicators of wetland health ( Wilcox et al 2002 ; Timmermans and Craigie 2003 ; Environment Canada and Central Lake Ontario Conservation Authority 2004 ; Uzarski et al 2005 ; Cooper et al 2018 ). Fish community-based indicators adopted by the GLCWC are a set of metrics that are combined to yield IBI scores for distinct plant zones (based on Uzarski et al 2005 and Cooper et al 2018 ).…”

“…Recognition of the importance of coastal wetlands to Great Lakes fishes (e.g., Jude and Pappas 1992 ) initiated a movement toward using fishes as indicators of wetland health ( Wilcox et al 2002 ; Timmermans and Craigie 2003 ; Environment Canada and Central Lake Ontario Conservation Authority 2004 ; Uzarski et al 2005 ; Cooper et al 2018 ). Fish community-based indicators adopted by the GLCWC are a set of metrics that are combined to yield IBI scores for distinct plant zones (based on Uzarski et al 2005 and Cooper et al 2018 ). These fish-based IBIs were initially formulated for Typha (cattail) - and Schoenoplectus (bulrush) -dominated wetlands and were designed to be used in all five Great Lakes ( Uzarski et al 2005 ).…”

“…These fish-based IBIs were initially formulated for Typha (cattail) - and Schoenoplectus (bulrush) -dominated wetlands and were designed to be used in all five Great Lakes ( Uzarski et al 2005 ). Cooper et al (2018) built on and expanded those to additional vegetation types. The IBIs were tested against multiple water quality and anthropogenic disturbance gradients.…”