Walleye
The walleye is a large freshwater fish in the perch family, native to North America. Its reflective eyes help it feed in dim light.
Yellow perch: A freshwater fish in the perch family, native to North America and widely valued as food. A close relative that helps place walleye within the perch family.
Tapetum lucidum: A reflective layer in the eyes of many vertebrates that increases light available to photoreceptors. This layer gives walleye eyes their reflective appearance and supports vision in dim conditions.
Walleye fishing: Recreational and commercial fishing directed at walleye populations. The species supports popular fisheries across much of its North American range.
Eutrophication: The enrichment of water with nutrients, often causing excessive algal growth and reduced oxygen. Nutrient pollution can alter the clear, oxygenated habitats that support walleye.
Lake Erie: The southernmost and shallowest of the North American Great Lakes, shared by the United States and Canada. Its walleye population supports one of North America’s largest freshwater fisheries.
Sauger: A freshwater fish in the perch family, closely related to walleye and native to North America. Walleye and sauger are sister species that can hybridize.
Diel vertical migration: Daily movement of aquatic organisms between deeper water and the surface, often following light or food. Walleye often shift depth as light and prey availability change through the day.
Fish stocking: The deliberate release of hatchery-raised or transferred fish into a water body. Managers stock walleye to establish, supplement, or restore fisheries.
Invasive species: Species introduced beyond their native ranges that spread and cause ecological or economic harm. Introduced predators and competitors can change walleye prey and survival.
Lake Winnipeg: A large lake in Manitoba, Canada, draining north through the Nelson River. Its productive walleye fishery is important to commercial and recreational harvest.