Use of the index of biotic integrity to assess physical habitat degradation in warmwater streams

Abstract

Indices o biotic integrity (IBI) were computed or two annual ish collections rom 27 locations along the blu line bordering the Mississippi River alluvial plain in northwestern Mississippi . Study sites exhibited varying degrees o physical habitat degradation due to accelerated channel erosion . Objectives o index application were to quanti y existing environmental quality and to test the IBI as a tool or relating ish population characteristics to physical degradation . Physical habitat data were collected concurrently with ish at all sites, and physical habitat descriptors were compared with the IBI scores and component metrics .Three to 23 ish species were captured rom each site, and species richness explained 64-70% o the variance in IBI scores . Fish collections were dominated by insectivores tolerant o habitat and water quality degradation . Suckers and piscivores were relatively uncommon .The IBI scores were generally not re lective o physical habitat conditions . Variation in IBI scores was indicative o only the grossest di erences in physical habitat quality . Weak relationships between physical habitat quality and IBI scores may have been due to large temporal variations in biotic integrity typical o degraded habitats . Alternatively, water quality degradation, which we did not measure, may have con ounded relationships between physical habitat and ish metrics .Regional application o the IBI as a habitat assessment tool in landscapes with widespread physical degradation must overcome lack o suitable re erence sites, large temporal variation in IBI scores, and small numbers o ish per collection, leading to lower con idence levels or IBI scores . The scarcity o lightly impacted sites may hinder detection o biotic integrity response along gradients o physical habitat quality .

Spatial and temporal patterns in fish assemblages of upper coastal plain streams, Mississippi, USA

“…Notropis rafinesquei, endemic to the Yazoo River basin, and Cyprinella camura were dominant species in all three streams; both are tolerant of shallow, sandy streams and are characteristic of incised channels throughout northern Mississippi (Shields et al, 1995). Luxilus chrysocephalus is considered intolerant of degraded conditions (Shields et al, 1995) and was dominant only in Buckhorn Creek, the only unchannelized study stream.…”

“…Because assemblages respond in diverse ways to these factors, quantification of variability must be repeated under many different conditions. Spatio-temporal variability in fish assemblage structure has received little attention in channelized, incised, sand-bottom streams of the upper Gulf of Mexico Coastal Plain, USA, (but see Shields et al, 1995), although some studies addressed the issue in other Coastal Plain streams (e.g. Ross et al, 1987).…”

Influence of spatial resolution on assessing channelization impacts on fish and macroinvertebrate communities in a warmwater stream in the southeastern United States

“…We calculated darter species richness as the number of darter species, and EPT taxa richness as the number of EPT families. Proportion of tolerant fish species was calculated based on the percent of captures of fish species considered to be tolerant of habitat degradation (Shields et al 1995), while proportion of tolerant macroinvertebrate taxa was calculated based on the percent of captures of macroinvertebrate taxa with tolerance values greater than 7.0 (Barbour et al 1999;Tetra Tech 2003).…”

Use of Ecohydraulic-Based Mesohabitat Classification and Fish Species Traits for Stream Restoration Design

“…Environmental agencies accompany mesohabitat surveys with biological surveys for fish and/or macroinvertebrates typically, and both surveys are used to compare with reference stream conditions to generally assess a stream reach's biological integrity [65,66]. Studies assessing the ecological health of streams have extensively relied on linkages between physical habitat quality and biota composition [22,[66][67][68][69][70]. Kaufmann et al (1999) [64] described a field protocol of longitudinally mapping mesohabitat units in sequence, and collecting basic dimensions of each unit and information on riparian vegetation and microhabitat features, i.e., large woody debris (LWD), overhanging bank vegetation, and large rocks.…”