Development of a Multimetric Index for Assessing the Biological Condition of the Ohio River

Abstract

The use of fish communities to assess environmental quality is common for streams, but a standard methodology for large rivers is as yet largely undeveloped. We developed an index to assess the condition of fish assemblages along 1,580 km of the Ohio River. Representative samples of fish assemblages were collected from 709 Ohio River reaches, including 318 ''leastimpacted'' sites, from 1991 to 2001 by means of standardized nighttime boat-electrofishing techniques. We evaluated 55 candidate metrics based on attributes of fish assemblage structure and function to derive a multimetric index of river health. We examined the spatial (by river kilometer) and temporal variability of these metrics and assessed their responsiveness to anthropogenic disturbances, namely, effluents, turbidity, and highly embedded substrates. The resulting Ohio River Fish Index (ORFIn) comprises 13 metrics selected because they responded predictably to measures of human disturbance or reflected desirable features of the Ohio River. We retained two metrics (the number of intolerant species and the number of sucker species [family Catostomidae]) from Karr's original index of biotic integrity. Six metrics were modified from indices developed for the upper Ohio River (the number of native species; number of great-river species; number of centrarchid species; the number of deformities, eroded fins and barbels, lesions, and tumors; percent individuals as simple lithophils; and percent individuals as tolerant species). We also incorporated three trophic metrics (the percent of individuals as detritivores, invertivores, and piscivores), one metric based on catch per unit effort, and one metric based on the percent of individuals as nonindigenous fish species. The ORFIn declined significantly where anthropogenic effects on substrate and water quality were prevalent and was significantly lower in the first 500 m below point source discharges than at least-impacted sites nearby. Although additional research on the temporal stability of the metrics and index will likely enhance the reliability of the ORFIn, its incorporation into Ohio River assessments still represents an improvement over current physicochemical protocols.

Site length for biological assessment of boatable rivers

“…By assessing the ecological status of this river site using pooled electrofishing and trawl catches and day and night electrofishing catches, respectively, it was concluded that electrofishing at night may substitute for additional sampling gears in large rivers (Figure 1; Wolter and Freyhof, 2004). Simon and Sanders (1999) and Emery et al (2003) arrived at a similar conclusion for the Ohio River. Erős et al (2008) reported that night electrofishing in the summer more than doubled the number of species collected by day electrofishing in the Danube River, Hungary; species richness curves were strongly flattening by day electrofishing 17-33 MWCW, but not by night electrofishing the same distance.…”

“…Lyons, 1992a;Lazorchak et al, 2000;Hughes et al, 2002;Reynolds et al, 2003;Maret and Ott, 2004;Hughes and Peck, 2008), while others support the use of a fixed distance (Yoder and Smith, 1999;Emery et al, 2003;Flotemersch and Blocksom, 2005).…”

Influence of Geomorphology on Fish Fauna of a Small Mississippi Bluffline Stream

“…Average catch per unit of effort was highest in the lower group of sites (5.15 kg/hr), followed by upper (2.12 kg/hr) and middle (1.98 kg/hr) channels while number per unit of effort was higher in the upper channels (486 fish/hr), followed by lower (458 fish/hr) and middle (289 fish/hr) reaches. Intolerant species [12,13] comprised a greater percentage of the catch in the upper group, 16.7%, versus 11.1% for middle and 7.1% for lower groups of sites.…”

River health assessment in a large river: Bioindicators of fish population

“…The most widely used methods were community-based approaches such as IBI (index of biological integrity) (Simon and Emery, 1995;Ganasan and Hughes, 1998;Lyons et al, 2001;Emery et al, 2003;Araújob et al, 2003;Long and Walker, 2005;TejerinaGarro et al, 2006;Pinto et al, 2006;Zhu and Chang, 2008), FBI (the fish-based index) (Oberdorff et al, 2002), TFC (the target fish community) (Meixler, 2011) and some other multiple-metric methods (Pont et al, 2006;Bergerot et al, 2008;Terra and Araújob, 2011). However, these methods have presented unique challenges (Simon and Sanders, 1999).…”