A Biointegrity Index (IBI) for Coldwater Streams of Western Oregon and Washington

Abstract

We developed, tested, and applied an index of biological integrity (IBI) for fish and amphibian assemblages in coldwater streams of the Oregon and Washington Coast Range. A probability sample of 104 wadeable sites was quantitatively sampled for fish and amphibian assemblages as well as physical and chemical habitat from 1994 to 1996. Natural gradients and anthropogenic disturbances were assessed by examining digital data for catchment‐scale road density and vegetation cover, along with site‐scale physical and chemical habitat data. A set of 109 candidate metrics was evaluated for variance properties, redundancy, and responsiveness to multiple measures of disturbance, resulting in the selection of eight metrics for the index. The IBI itself was subsequently evaluated for variance and responsiveness to disturbance, then compared against an independently selected set of 101 reference sites that had minimal anthropogenic disturbance. Our IBI was fairly precise, with an among‐stream variance–residual variance (sampling time, measurement error, and crew error) ratio of 4.0 (indicating a theoretical maximum correlation of 0.80 between the IBI and a predictor variable with a similar ratio). The IBI was significantly correlated with multiple estimates of anthropogenic disturbance, and reference sites had significantly higher IBI scores than the nonreference sites. Low IBI scores were associated with low bed stability, instream cover, and riparian cover and structural complexity but high percent fine substrate, road density, and human disturbances of riparian areas. Applying this IBI, we assessed fish assemblage condition in the Coast Range, inferring our results to all mapped (1:100,000‐scale) wadeable streams in this region. Using 2 SDs from the reference sites mean as a biological criterion, 45% of stream kilometers (10,646 km) were classified as impaired. High IBI scores clustered near national parks and wilderness areas. Our results indicate that minimally disturbed regional reference sites and probability survey designs, which produce statistically representative sites and inferences with known confidence bounds, offer considerable advantages over least disturbed reference sites and hand‐picked survey sites for making regional ecological assessments.

A Preliminary Fishery Quality Index for Portuguese Streams

“…A similar pattern may be expected between fishery quality and the coldwater IBIs of Mundahl and Simon (1999), Mebane et al (2003), and Hughes et al (2004), which included salmonid size, abundance, recruitment metrics, or a combination thereof. Additionally, reduction in or absence of brown trout, as well as chubs and nases (both moderately sensitive), in moderately to highly disturbed cold waters is not associated with the presence of other game fishes sought by Portuguese anglers.…”

“…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.…”

Divergent reaction of fish metrics to human pressures in fish assemblage types in Europe

“…In contrast, many other studies in the past used species presence/absence data for impact assessment of running waters (Fausch et al, 1984;Lyons et al, 1996;Oberdorff et al, 2002;Hughes et al, 2004;Johnston et al, 2011) either because of lacking standards in methods of sampling or lack of data due to higher costs in the sampling. In our analyses, metrics based on presence/absence (nsp) responded in all four river types (Fig.…”

“…Based on the concept of the ''index of biotic integrity'' (IBI), (Karr, 1981) and under the frame of the ''Clean Water Act'', many scientists tried to find appropriate fish metrics and fish indices for the assessment of the ecological status of running waters (Fausch et al, 1984;Lyons et al, 1996;Oberdorff et al, 2002;Hughes et al, 2004;Johnston et al, 2011). Many were successful but the results were restricted to regional extents.…”

Desenvolvimento De Índices Multimétricos Para Utilização Em Programas De Monitoramento Biológico Da Integridade De Ecossistemas Aquáticos

“…A utilização de macroinvertebrados bentônicos para o desenvolvimento de índices é atualmente extremamente comum, especialmente para avaliação da integridade de rios e riachos (Barbour et al 1996, Klemm et al 2003, Böhmer et al 2004, Moya et al 2007. Além disso, outros organismos passaram a ser utilizados como bioindicadores para o desenvolvimento dos índices, como pássaros (Bryce et al 2002), anfíbios (Hughes et al 2004), macrófi tas aquáticas (Miller et al 2006), perifíton (Hill et al 2003) e fi toplâncton (Lacouture et al 2006). No Brasil, existem três trabalhos publicados em revistas internacionais que apresentam desenvolvimento de índices multimétricos: (1) para macroinvertebrados em riachos (Baptista et al 2007); (2) para peixes em rios (Araújo et al 2003, Bozzeti & Schulz 2004.…”