Can Rapid Assessments Predict the Biotic Condition of Restored Streams?

Barbara Doll,David Penrose,Gregory Jennings,Mark Fernandez,Jean Spooner,Joseph Usset,James Blackwell

doi:10.3390/w8040143

Abstract

Five rapid visual stream assessment methods were applied to 65 restored streams in North Carolina, and the results were correlated with measured macroinvertebrate community metrics to evaluate predictive ability. The USEPA Rapid Bioassessment Protocol (RBP), USDA Stream Visual Assessment Protocol (SVAP), Peterson’s Riparian Channel and Environmental Inventory (RCE), NCSU Eco-Geomorphological Assessment (EGA), and NCSU Stream Performance Assessment (SPA) were applied by teams with expertise in hydrology, fluvial geomorphology, and aquatic ecology. Predictions of most macroinvertebrate metrics were improved by re-weighting assessment variables using principal component analysis (PCA) and including watershed factors (e.g., size, slope, land use). The correlations of EGA, RCE, SPA and SVAP assessment results to macroinvertebrate metrics were most improved by variable re-weighting using PCA, while the correlations of RBP were most improved by adding watershed parameters. Akaike’s Information Criterion (AIC) indicates that PCA re-weighting including watershed parameters improves the predictor model for the total number of dominant EPT taxa more than using the sum total raw points for all five assessment methods. To demonstrate the application of the study results, a single-value index was generated for the RBP method using principal component regression (PCR) based on the EPT (Ephemeroptera, Plecoptera and Trichoptera) taxa metric.

Highlights

USEPA [5] ascertains that strengthening structural or functional components will improve water quality and habitat, which will lead to improvements in aquatic and terrestrial communities that depend on water
We suggest in this paper that a viable alternative is to minimize the subjectivity of variable weights in order to explicitly define stream health in terms of macroinvertebrate metrics
Linear regression of macroinvertebrate metrics to the five stream assessment methods resulted in some significant relationships; unexplained variance in data was high, as demonstrated by low coefficients of determination

Summary

Introduction

USEPA [5] ascertains that strengthening structural or functional components will improve water quality and habitat, which will lead to improvements in aquatic and terrestrial communities that depend on water. There is a need to define the relationships between physical attributes and habitats in restored streams with respect to the biotic communities that serve as indicators of stream health similar to what has been done in un-restored streams [6,7,8]. These relationships can in turn be used to guide future restoration design, monitoring and assessment

Methods

Results

Conclusion