Habitat Requirements of Stream Spawning Walleye: An Evaluation of Habitat Suitability Index (HSI) Information and Lake Erie/Niagara River Tributaries

Abstract

A Lake Erie Walleye Spawning Stream Rehabilitation Plan was initiated by the New York State Department of Environmental Conservation to stabilize and enhance walleye recruitment in Lake Erie. One component of the plan includes stream habitat assessment to determine candidate streams for rehabilitation efforts. Information from research literature has been compiled to develop a Habitat Suitability Index (HSI) model and identify optimum habitat requirements for walleye. The model hypothesizes species-habitat relationships which can vary by geographical area. The objectives of my thesis project were to: (1) determine habitat conditions in a local stream where walleye spawn (control site); (2) compare these data with the HSI; and (3) use the data to evaluate four tributaries as candidates for walleye rehabilitation efforts. Spawning walleye were observed in the control stream on four days over the two-year period of study. Velocity, depth, and water temperature conditions where walleyes spawned were at the lower end of or below the optimum ranges specified in the HSI. However, optimum HSI conditions for velocity, depth, and water temperature generally do not exist in the control stream. Substrate, dissolved oxygen, and pH variables were optimum when compared to the HSI. Cluster analysis was used to group streams according to their similarities in velocity, depth, water temperature, and substrate. Significant differences (p ?0.05) in these parameters occurred among all grouped streams. No candidate stream evaluated in this study fully met the conditions found in the control stream. The candidate stream most similar to the control stream was Eighteenmile Creek. The candidate stream most similar to the national HSI model was Ellicott Creek.