Determining Spawning Occurrence and Reproductive Potential of Shenango River Lake Walleye

Abstract

The objective of this project was to achieve an assessment of walleye (Sander vitreus) spawning through the collection of eggs and physico-chemical data in the Shenango River, from the Shenango River Lake extending upstream approximately 24 river kilometers. It is generally thought that successful spawning of walleye in Pennsylvania is nearly non-existent, but the research to support this is limited. The data collected during sampling included river depth, flow velocity, water temperature, dissolved oxygen, pH, and river substrate content. This data will provide a baseline for future studies of the Shenango River and similar fisheries. This information was compared with that of other studies on walleye spawning habitat to establish a Walleye Spawning Qualitative Habitat Evaluation Index (WSQHEI). Walleye spawning attempts by Shenango River Lake walleye in the Shenango River was confirmed by this study. The WSQHEI appeared unsuitable for predicting walleye spawning in the Shenango River. Physico-chemical data displayed minimal gradients, which limited the development and effectiveness of the WSQHEI. This occurred because sampling was restricted to areas conducive to walleye spawning based upon literature of known environmental variables. Although walleye spawning activity was unrelated to environmental conditions among sites, migration distance was negatively correlated with walleye spawning activity. Sampling in 2008 and 2009 indicated that spawning occurrence decreased as distance from Shenango River Lake increased. The WSQHEI could be useful for baseline assessments when little or no data are available about the walleye spawning activities in a lotic system.