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

Matthew J Cooper,Terry N Brown,Douglas A Wilcox,Donald G Uzarski,Gary A Lamberti,Lucinda B Johnson,Valerie J Brady,Greg P Grabas,Jan J H Ciborowski,Carl R Ruetz,Ashley H Moerke,Joseph P Gathman

doi:10.1007/s10661-018-6950-6

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.

Highlights

Human activities that alter physical, chemical, or biological processes of aquatic ecosystems affect the structure of resident biotic communities (Karr 1981; Fausch et al 1984)
Fish data were summarized as catch of each species per net per night in each vegetation zone at each wetland, which we considered the catch per unit effort (CPUE) for that zone
A number of metrics functioned well in several of the Index of Biotic Integrity (IBI) (Table 1); metrics used in all four IBIs included Nonnative species richness and % Richness of species sensitive to environmental degradation [sensitivity based on Plafkin et al 1989 and Lyons 2006, 2012]

Summary

Introduction

Human activities that alter physical, chemical, or biological processes of aquatic ecosystems affect the structure of resident biotic communities (Karr 1981; Fausch et al 1984). Coastal wetlands occur throughout the Great Lakes where hydrology (e.g., wave and current energy) is sufficiently quiescent for emergent vegetation to persist, and where sediment is conducive to macrophyte growth (Albert et al 2005). These shallow, productive ecosystems provide critical habitat for many fish species of ecological and economic importance (Chubb and Liston 1986; Klarer and Millie 1992; Parker et al 2012). Broad-scale monitoring is essential for identifying wetlands most in need of protection or restoration, to evaluate the effectiveness of restoration projects, and for both local and regional time-trend analysis

Objectives

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Conclusion