Walleye Stream Habitat Map

Katie Kahl - kkahl@tnc.org
link DOWNLOAD FILE: Full Map

Download the Factsheet

Walleye stream habitat in relation to regional ecological and social values
This data layer uses walleye stream habitat as a proxy for other native migratory fish in the Western Lake Erie Basin (WLEB). Walleye (Sander vitreus) and other sport fish species fuel are worth tens of millions to the WLEB economy; walleye and sauger are especially popular, luring 0.6 million of the 1.7 million anglers who contributed US$1.9 billion to the Great Lakes basin’s economy in 2011. There are at least 30 species supplying the fishing industry in the Lake Erie basin that rely on streams for spawning; it is essential to preserve the accessibility and overall quality of upstream spawning habitat in order to sustain these fish populations. The vital connection between upstream habitats and Lake Erie has been difficult to maintain due to the installation of hydroelectric dams, poorly designed road-stream crossings, and various structures to alleviate storm and erosion damage, including dams and sea walls. Other threats to the quality of stream habitats include non-point source pollution from agricultural and urban land, the contamination of sediments with toxic compounds, the presence of competitive or parasitic invasive species (e.g. sea lamprey), and temperature increases from climate change. The Western Lake Erie Coastal Conservation Vision Project recognizes the ecological and socioeconomic importance of maintaining healthy stream habitat for fish populations like walleye, and therefore includes this data layer to ensure that stream habitat quality is incorporated into the optimization of areas for conservation.

Walleye stream habitat layer
The Lake Erie Biodiversity Conservation Strategy (LEBCS) established a goal of having at least 50% of each stream type– based on the Midwest Fish Habitat Partnership classification–connected to Lake Erie in order to provide access to spawning areas for migratory fish. The WLECCV includes this data layer to help stakeholders achieve the LEBCS goal by ensuring that the highest predicted quality stream habitat is included when determining optimal areas for conservation. To create this data layer for the U.S., the National Fish Habitat Partnership (NFHP) assessed fish habitat and identified 19 natural habitat characteristics that were then used to calculate potential habitat quality for walleye species in particular. Natural habitat characteristics that most influenced potential habitat quality were the drainage area of a stream’s watershed, wetland area in the watershed, mean annual precipitation, modeled stream temperature, and slope of the watershed.

Data for the Ontario side of the basin was created to approximate the U.S. index scores using the Ontario Integrated Hydrology data as the base stream layer and a scoring process based on professional judgment.  Based on personal communication received from Ontario fisheries professionals at a stakeholder workshop held in Essex, Ontario, in October of 2014 all of the streams in this portion of Ontario should receive a “poor” score for walleye habitat.  We assigned habitat scores based on steam size by assigning headwater streams a score of 5; creeks a score of 10; and small rivers a score of 15.