Injury frequency and severity in crayfish communities as indicators of physical habitat quality and water quality within agricultural headwater streams

Authors: WOOD, TYLER - Bowling Green State University; Smiley, Peter - Rocky; GILLESPIE, ROBERT - Indiana University-Purdue University; Gonzalez, Javier; King, Kevin

Submitted to: Environmental Monitoring and Assessment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2020
Publication Date: 3/10/2020
Citation: Wood, T.C., Smiley, P.C., Gillespie, R.B., Gonzalez, J.M., King, K.W. 2020. Injury frequency and severity in crayfish communities as indicators of physical habitat quality and water quality within agricultural headwater streams. Environmental Monitoring and Assessment. 192:227. https://doi.org/10.1007/s10661-020-8171-z.
DOI: https://doi.org/10.1007/s10661-020-8171-z

Interpretive Summary: Agricultural conservation practices are frequently used to reduce the impacts of agriculture on stream ecosystems. The ecological effect of many conservation practices on the aquatic biota has not been evaluated. Information on the biota-habitat relationships within agricultural streams can provide predictions about the ecological effects of conservation practices. We evaluated the relationships of novel bioindicators describing prevalence and severity of injuries of common stream invertebrate (crayfish) with physical habitat quality, water quality, and crayfish abundance within agricultural headwater streams in Indiana, Michigan, and Ohio. We found that these novel bioindicators were most strongly influenced by crayfish abundance and physical habitat quality, but not water quality. Our results represent the first documentation of the relationships between crayfish injury with physical habitat quality, water quality, and crayfish abundance. Our results suggest that conservation practices that lead to increases in the diversity of water depth, water velocity, and substrate types in agricultural streams in the Midwestern United States are are more likely to positively benefit crayfishes than water quality improvements. Our results will assist state agencies, federal agencies, non-profit groups, and consulting agencies involved with conservation and management of macroinvertebrates as well as those involved with managing agricultural watersheds.

Technical Abstract: Crayfishes (Order Decapoda) are common inhabitants of agricultural headwater streams in the Midwestern United States that have been impacted by physical habitat degradation and contamination by agricultural pollutants. The frequency and severity of injuries within crayfish communities are indicators of crayfish aggression, which is influenced by physical, chemical, and biotic factors. Previous studies have not evaluated the relationships of the frequency and severity of crayfish injuries with physical habitat quality, water quality, and biotic factors within agricultural headwater streams in the Midwestern United States. Understanding these relationships will assist with determining if crayfish injury variables can serve as an indicator of physical habitat quality or water quality in agricultural headwater streams. We sampled crayfishes, documented the frequency and type of injuries, and measured instream habitat and water chemistry in 2014 and 2015 within 12 agricultural headwater streams in Indiana, Michigan, and Ohio. We documented five native crayfish species from 1641 adult captures. The most commonly captured species were Faxonius immunis, Faxonius rusticus, and Faxonius propinquus. Linear mixed effect model analyses indicated that four crayfish injury response variables were positively correlated (p < 0.05) with crayfish density, physical habitat quality, and water velocity diversity. Linear mixed effect model analyses also indicated that the crayfish injury response variables were more strongly correlated with crayfish density than physical habitat quality or water quality. Our results indicate that response variables describing the severity and frequency of crayfish injuries can be effective indicators of physical habitat quality in agricultural headwater streams.