Development and Validation of an Index of Biotic Integrity for Coldwater Streams in Wisconsin

Abstract

The index of biotic integrity (IBI). developed from information on the structure, composition, and functional organization of fish assemblages, is used to assess the health of aquatic ecosystems. We analyzed two large statewide data sets on stream fish assemblages to develop and test a version of the IBI for application to Wisconsin coldwater streams (maximum daily mean water temperature usually <22°C). This new IBI is needed because fish assemblages in Wisconsin coldwater streams differ significantly from those in warmwater streams (maximum daily mean temperature >24°C), for which an IBI already exists. High‐quality coldwater streams have few species, with salmonids and cottids dominating. and lack many of the taxonomic groups that are important in high‐quality warmwater streams. In contrast, high‐quality warmwater streams have numerous species, and cyprinids, catostomids, centrarchids, and percids typically dominate. Environmental degradation often causes an increase in species richness in coldwater fish assemblages, the opposite of what occurs in warmwater assemblages, as a small number of coldwater species are replaced by a larger number of more tolerant eurythermal and warmwater species. The new coldwater IBI has five metrics: (1) number of intolerant species, (2) percent of all individuals that are tolerant species, (3) percent of all individuals that are top carnivore species, (4) percent of all individuals that are native or exotic stenothermal coldwater or coolwater species, and (5) percent of salmonid individuals that are brook trout Salvelinus fontinalis. No regional or stream‐size adjustments in metric scoring criteria are needed. Relative coldwater IBI scores and ratings of stream sites throughout Wisconsin closely match independent rankings of environmental quality on the basis of physical habitat and water quality of the sites. Variation in IBI scores within and among years is gencrally low. The new coldwater IBI is not appropriate for coolwater streams (typical maximum summer daily mean temperature 22–24°C).

A Preliminary Fishery Quality Index for Portuguese Streams

“…Hughes et al (1998) and Mebane et al (2003) reported that their IBIs had greater among-site versus within-site variability (signal/noise) than the metrics forming them. But Hughes et al (2004) and Whittier et al (Lyons et al 1996;Mundahl and Simon 1999;Ferreira et al 2007;Whittier et al 2007). However, predictive IBI modeling (which calibrates for natural gradients in size, temperature, and elevation) does not necessarily require separation into warmwater and coldwater models (Oberdorff et al 2002;Pont et al 2006Pont et al , 2009.…”

“…The IBI of Oliveira and Ferreira (2002) has two metrics (percent native individuals and percent tolerant individuals) that will reduce IBI scores with increased numbers of tolerant nonnative game fish species (higher FQI scores). Lyons et al (1996) noted that an IBI score does not indicate fishery quality because stocked fish in Wisconsin streams may yield high quality fisheries, despite having low or intermediate IBI scores. Whittier et al (1997) reported that piscivores, especially nonnative piscivores introduced to improve fishing, were associated with lower minnow species richness (lower IBI scores) in northeastern U.S. lakes.…”

Conservation practice establishment in two northeast Iowa watersheds: Strategies, water quality implications, and lessons learned

“…Fish Index of Biotic Integrity and fish richness studies indicated slight improvement at several SMCW sites. The slimy sculpin (Cottus cognatus) was also first found in 2001, which was a further positive development because this fish is classified as intolerant of environmental degradation and as a stenothermal cold water species (Lyons et al 1996;Mundahl and Simon 1999). The slimy sculpin was the dominant fish species found at the Bloody Run Creek site during each annual assessment and accounted for 95% of the fish population during six of the ten years.…”

Natural and Human Influences on Fish Species Richness in Small North Temperate Lakes: Implications for Bioassessment

“…While not unexpected, the result is highly relevant to implementation of biological monitoring based on fish. In most IBI's, the typical response of native species to degradation is a reduction in species richness (coldwater stream IBI provides a notable exception (Lyons et al 1996)). However, the game fishes in this study are native, and undergo an increase in richness at low to moderate levels of human impact.…”