Walleye are a popular freshwater game fish, widely sought after across North America. This article examines their presence in Maine, offering insight into the distribution of this popular species.
The Walleye’s Natural Range
Walleye are native to freshwater systems across much of Canada and the northern United States, extending east of the Rocky Mountains. Their natural distribution centers around the Great Lakes region and the upper Mississippi River basin, reaching as far south as Arkansas and Alabama. This species thrives in cool, well-oxygenated waters, inhabiting large lakes and rivers with turbid conditions and substrates composed of rock or gravel. Walleye are found in deeper parts of these water bodies, preferring environments that offer refuge from bright light. The natural conditions required by walleye mean that Maine falls outside their primary native range.
Walleye Presence in Maine
Walleye are not native to Maine, and there are no established, widespread populations of this fish in the state. Reports of walleye in Maine stem from isolated occurrences, linked to illegal introductions rather than natural colonization. While some anecdotal accounts suggest localized populations, these are not thriving or widespread. The Maine Department of Inland Fisheries and Wildlife (MDIFW) considers the unauthorized stocking of any fish species illegal due to the potential harm to native aquatic ecosystems.
Any presence of walleye in Maine waters is likely the result of these illegal stockings. Such introductions are a concern for state biologists because walleye require specific habitat conditions not broadly available across Maine’s diverse aquatic environments. The state’s focus remains on protecting and managing its native cold-water fisheries, which are vulnerable to non-native species.
Identification and Ecological Considerations
Identifying a walleye involves observing distinct characteristics that differentiate it from native Maine fish species like yellow perch. Walleye have a long, slender body that is golden to olive-brown, with diffuse dark blotches rather than prominent vertical bars. Key features include an opaque, reflective layer in their large eyes, giving them a “marble-eyed” appearance, and a distinct white tip on the lower lobe of their tail fin. In contrast, yellow perch exhibit distinct dark vertical bars on their brownish-yellow bodies and lack the white tail tip.
The introduction of non-native species, even in isolated instances, poses significant ecological risks. Walleye are apex predators within their natural range and can disrupt ecosystems where they are introduced. They can outcompete native fish for food resources and prey on vulnerable native populations, including trout and salmon fry. Such introductions can lead to declines in native species, altering food webs and causing irreversible changes to aquatic biodiversity.