Effect of Wetland Quality on Sampling Bias Associated with Two Fish Survey Methods for Coastal Wetlands of the Lower Great Lakes

Abstract:

A variety of sampling gear and protocols have been used in the literature to characterize the fish communities of Great Lakes coastal wetlands, and these include passive-capture gears such as gill nets, trap nets, and fyke nets, as well as active-capture gears such as beach seines, trawls, plankton nets and electroshockers (backpack or boat electrofishing). The goal of this study is to investigate sampling biases associated with two different sampling protocols, both of which are currently used by researchers to develop indicators of habitat quality for coastal wetlands of the Great Lakes basin. We wanted to compare differences with respect to the taxonomic affiliation, mode of feeding, size and number of fish caught by the two different methods. The feeding mode was of particular interest to us because fish communities tend to change from one dominated by piscivores to one dominated by benthivores and planktivores as wetlands become degraded, and if sampling bias reflected differences in feeding mode of the fish, then wetland quality would be an important factor to consider. Our results will provide a scientific basis to set criteria for proper cross- study comparisons, and to guide development of meaningful long-term, basin-wide monitoring programs.