Evaluation of a channelized stream using water quality and macroinvertebrate studies

Abstract

Water is the human population's most scarce resource. Human impacts such as urbanization, agriculture and channelization have an effect on water and stream quality. Channelization, the straightening of streams to better fit human land use needs, was a common practice in northeast Ohio. While the channelization of streams is useful for agriculture and for other purposes, it is a major stress for natural aquatic systems. A 4 km-long (~2.5 miles) portion of Snyder Ditch, Orwell, NE Ohio, was channelized in the early 1900s for agricultural drainage. This study evaluates stream quality of this channelized system utilizing water chemistry, macroinvertebrate diversity studies and stream habitat assessment. Stream quality was compared against Ohio EPA stream use designation of warmwater habitat for three sampling dates: May, August and October 2013. It was initially hypothesized that stream quality would not reach warmwater habitat standards, as designated by the Ohio EPA. The results surpassed the original expectation of the stream; however, still did not reach warmwater habitat designation criteria. Dissolved oxygen levels were near the required 5 mg/L with most of the sampling dates having low levels of nutrients (nitrate, phosphate and ammonia). There was good overall diversity and density of macroinvertebrates and a higher than anticipated number of pollution sensitive taxa. The largest difference in stream quality was due to the stream habitat or lack thereof. Areas that contained some stream sinuosity, better substrate or more diverse riparian area had better density and diversity of macroinvertebrates. Therefore, with some habitat alterations or restoration, the stream quality has the potential to improve to warmwater criteria. This work, in addition to other ongoing projects, may lead to a better understanding of environmental parameters at this site, which would help land-owners develop better strategies for land management and restoration.