An Index of Biotic Integrity (IBI) for Fish Assemblages in the Littoral Zone of Great Lakes' Areas of Concern

Abstract

Karr's Index of Biotic Integrity (IBI) approach provides a biological measure of ecosystem health using a wide spectrum of metrics which can be extracted from fish catch data obtained using standardized methods. Extensive electrofishing surveys of littoral fish assemblages, conducted in three Great Lakes' Areas of Concern, provided the basis for developing a lacustrine IBI that was 12 metrics of three broad types: (i) species composition, (ii) trophic composition, and (iii) abundance and condition. In contrast with lotic IBIs where diversity and abundance metrics have mostly been used, several biomass metrics were adopted to accommodate the large size range of lentic fishes. The variability of repeated measures was low enough to allow valid testing of intertransect differences with three to five samples per transect. Comparisons among survey areas showed significant differences consistent with the varying levels of ecosystem degradation. Analyses of mean IBI values with measures of submerged vegetation density and cover by transect produced significant positive correlations. This IBI developed for the Great Lakes' littoral zone, both by design and by demonstrated correlations, integrates the effects of four main factors influencing fish assemblages and hence revealing ecosystem health: exotic fishes, water quality, physical habitat supply, and piscivore abundance.

Development and use of the Wetland Fish Index to assess the quality of coastal wetlands in the Laurentian Great Lakes

“…We also used the fish information from Frenchman's Bay to calculate corresponding fish IBI scores (Minns et al 1994). Although their IBI was developed for Areas of Concern (AOC) littoral zones, Frenchman's Bay is adjacent to the Toronto AOC and has similar impacts.…”

“…A number of biological indicators have recently been developed for coastal wetlands and littoral habitats of the Great Lakes that involve the use of periphytic algae (McNair and Chow-Fraser 2003), benthic invertebrates (Wilcox et al 2002;Weigel 2003), the fish community (Minns et al 1994), and water quality information (Chow-Fraser 2006). Of these, indicators involving fish are advantageous because they involve multiple trophic levels, require less total processing time, and yield results that can be easily interpreted by the general public (Karr 1981).…”

“…In developing this index, we will explore how the fish community reflects known environmental degradation. A second objective is to compare the utility of the WFI with other published indices of habitat quality, including the Water Quality Index (WQI; Chow-Fraser 2006), the near-shore fish Index of Biotic Integrity (IBI) developed by Minns et al (1994), and Weighted Species-Association Tolerance indices for Water Quality (WSATI-WQ) and Water Temperature (WSATI-WT; Wichert and Lin 1996). Third, we use fishassemblage information to generate WFI scores for two sites in Frenchman's Bay, a highly urbanized wetland of Lake Ontario that has degraded water-quality conditions in the north end because of runoff from a major provincial highway and measurably better water quality in the south end because of constant mixing with Lake Ontario water.…”

Development of a benthic multimetric index for the Serra da Bocaina bioregion in Southeast Brazil

“…Blocksom (2003) recommended it as the best option because it increases the sensitivity and stability of the resulting index. This method was originally used by Minns et al (1994) in the littoral zone of the Great Lakes. Ganasan and Hughes (1998) and Klemm et al (2003) used it in stream ecosystems.…”

Multimetric index for assessing ecological condition of running waters in the upper reaches of the Piabanha-Paquequer-Preto Basin, Rio de Janeiro, Brazil

“…BLOCKSOM (2003) recommended it as the best option because it increases the sensitivity and stability of the resulting index. This method was originally used by MINNS et al (1994) in the littoral zone of the Great Lakes. GANASAN & HUGHES (1998) and KLEMM et al (2003) used it in stream ecosystems.…”