Date Approved
5-26-2026
Graduate Degree Type
Thesis
Degree Name
Biology (M.S.)
Degree Program
Annis Water Resources Institute
First Advisor
Dr. Matthew Cooper
Second Advisor
Dr. Carl Ruetz III
Third Advisor
Dr. Donald Uzarski
Academic Year
2025/2026
Abstract
In recent decades, aquatic ecosystem conditions have been monitored using a tool known as an index of biotic integrity (IBI). An IBI combines taxon-specific metrics into one score for easy interpretation of ecosystem health. The use of multiple IBIs, through the monitoring of multiple taxonomic groups, is beneficial in gaining a wider understanding of ecosystem conditions that would otherwise be limited by monitoring just one IBI. For example, a monitoring assessment may include a fish-based IBI and a macroinvertebrate-based IBI for determining ecosystem degradation. Though the benefits of multi-taxon IBI assessments are recognized, there are also challenges such as the potential for variation among different index scores. The Laurentian Great Lakes in North America are an example of a highly monitored ecosystem where the Great Lakes Coastal Wetland Monitoring Program (GLCWMP) assesses coastal wetland conditions through a multi-taxon IBI assessment. This program monitors four IBIs: fishes, macroinvertebrates, vegetation, and birds. The GLCWMP monitors over 1,000 coastal wetlands to support protection, restoration, and management. The goal of this study was to develop a novel approach for interpreting IBI variation among taxonomic groups to better understand ecosystem disturbance using the GLCWMP dataset. I modeled the four IBIs against a set of environmental variables to determine the strongest influences on IBI scores and variation among IBIs. Data were collected from wetlands across the five Laurentian Great Lakes, their connecting channels, and tributaries that included several coastal wetland types sampled over 13 years (2012-2024). The results indicate that each taxonomic group was influenced by a different set of environmental variables, which could explain the variation among IBIs. Water level fluctuations, land cover, and local wetland characteristics all had varying effects on each taxon IBI. Additionally, wetland region influenced taxon IBI scores in varying ways, highlighting spatial trends. Understanding the environmental influences on each taxonomic IBI will allow managers to build site-specific restoration targets that better align with ecological objectives. This study represents the first approach in understanding IBI variation across multiple taxonomic groups on a large temporal and spatial scale that spans 13 years and all five Great Lakes.
ScholarWorks Citation
Eberly, Emily A., "Understanding Variation Among Multiple Indices of Biotic Integrity in Great Lakes Coastal Wetlands" (2026). Masters Theses. 1180.
https://scholarworks.gvsu.edu/theses/1180
