|GILLESPIE, ROBERT - Indiana University-Purdue University|
|Smiley, Peter - Rocky|
|SANDERS, KATHRYN - Earth Source Inc Heartland Restoration Services|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/13/2015
Publication Date: 3/21/2015
Citation: Gillespie, R.G., Smiley, P.C., Sanders, K., King, K.W., Smith, D.R. 2015. Evaluation of the negative impacts of exposure to agricultural ditch water in fishes using streamside bioassays and field biomarkers. Meeting Abstract. 2015 Indiana Academy of Sciencs Meeting, March 21, 2015, Indianapolis, Indiana.
Technical Abstract: Land use in regions of the Midwest is dominated by crop agriculture that depends on ditch drainage systems for maximum productivity. Many drainage networks comprise headwater streams that have been degraded by alteration of habitat and by introduction of agrichemicals. Understanding the relative impacts of agricultural contaminants and habitat degradation on aquatic biota within agricultural headwater streams will provide information that can assist with the restoration of these streams. Since 2006, we have conducted annual ecological assessments of fishes, water chemistry, instream habitat, and riparian habitat in seven channelized headwater streams in the Upper Big Walnut Creek Watershed of central Ohio and three channelized headwater streams in the Cedar Creek Watershed of northeastern Indiana. Additionally, streamside bioassays using fathead minnows (Pimephales promelas) were completed over a two-year period (2010-2011) at the Cedar Creek study sites. Biomarker surveys of three fish species were made at three channelized headwater stream sites and one reference site in both watersheds during 2011-2013. Fish community metrics were more strongly correlated with instream habitat than either riparian habitat or water chemistry. These same fish-habitat relationships occurred across watersheds. Results from bioassays and biomarker surveys suggested that fishes have not experienced significant negative health effects from exposure to contaminants in agricultural headwater streams. Analysis of water chemistry data showed that concentrations of agricultural contaminants, such as herbicides, nitrate, and ammonia were typically below those known from laboratory studies to cause chronic toxicity in fishes. In general, our results suggest that conservation practices and land-use practices targeted only to prevention of agrichemicals to receiving streams will not result in significant improvement of fish community integrity. Restoration projects that lead to improvements in physical habitat quality, however, should result in positive changes to fish communities within agricultural headwater streams in the Midwestern United States.