|Smiley, Peter - Rocky|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/7/2008
Publication Date: 4/23/2008
Citation: Pritt, J., Smiley, P.C., Williams, L. 2008. Orangethroat Darter Population Responses to Habitat Differences within a Central Ohio Headwater Stream. Fifth Annual College of Food, Agricultural, and Environmental Sciences Undergraduate Research Forum Program Book. p. 8. Interpretive Summary:
Technical Abstract: The diversity and abundance of darters are often used as an indicator of habitat quality in streams. The orangethroat darter (Etheostoma spectabile) is a common fish in small to medium sized streams within portions of the midwest and southeast United States. Qualitative observations of orangethroat darters suggest these fishes are tolerant of silt and sluggish, turbid water associated with agricultural practices common to the midwest. However, this observation has not been examined quantitatively. Preliminary sampling documented a large orangethroat darter population in a reach of low habitat quality within Thorne Run, a headwater stream in central Ohio. This reach is characterized by heavy siltation, a trapezoidal cross-section, and a narrow herbaceous riparian zone. Immediately downstream is a reach with less siltation, variable cross-section morphology, and a wider forested riparian zone. We hypothesize that orangethroat darter population characteristics will differ between the two reach types in Thorne Run that represent different habitat conditions. The two adjacent reaches on Thorne Run were sampled twice in June 2007. Habitat was visually estimated using the quantitative habitat evaluation index (QHEI) and fish were collected by backpack electrofishing. We captured a total of 645 orangethroat darters ranging in length from 26 to 65 mm. QHEI scores were lower in the upstream than the downstream reach and confirmed our previous observations of habitat differences between the reaches. Length, weight, and abundance of orangethroat darters were compared between the reach types. No differences in mean length and weight were observed between reach types. Mean abundance was three times greater in the upstream degraded reach than the downstream reach. Orangethroat darter specimens will be dissected in the future to so we can assess if differences in reproductive and life history traits occur between the reaches. My initial results suggest orangethroat darters are tolerant to physical habitat degradation and its population characteristics may not be effective indicators of physical habitat quality.