ASABE Technical Library - Abstract

Abstract. Stream restoration aims to re-establish the structure, function, and diversity of streams that have been altered from their natural state. Effective restoration approaches address both physical and ecological aspects of stream environments. To assess the physical and ecological condition of a restored Oklahoma stream, this study investigated spatial and temporal variation in water temperatures around in-stream structures, along vertical profiles, and in shaded versus nonshaded reaches using automated temperature loggers. Also, fish species richness and diversity (Shannon-Weiner diversity index (H‘)) were quantified at nonshaded and shaded locations by sampling in the morning and afternoon using a seine. All research was conducted within undisturbed and restored reaches of Cow Creek, a third-order stream in Stillwater, OK. Mann-Whitney U tests, Kruskal-Wallis one-way analysis of variance (ANOVA) by ranks tests, and Pearson product-moment correlation coefficient (r) calculations were performed on the fish diversity measures. Results revealed that maximum daily water temperature was generally warmer downstream of in-stream structures and that fish species richness and H‘ were significantly different at different times of day but these differences were not related to riparian shading. This suggests that in-stream structures affect thermal regimes and that water temperature, more so than light, plays an important role in shaping fish distributions. In the future, stream restoration projects would benefit from considering the influence of in-stream structures on water temperature and water temperature on aquatic organisms.