03/21/2026
They are illusive on lake Simcoe… I personally never see on Simcoe and my dad ether …dad been fishingLake Simcoe for Little more than 25 years .
We see the odd Big Walleye caught from Lake Simcoe, but what happened to the historic walleye population?
Walleye didn’t disappear from Lake Simcoe because of one issue, they were hit by a long sequence of changes that disrupted every stage of their life cycle.
As the watershed developed, key spawning tributaries like the Holland, Maskinonge, and Beaver Rivers were altered by sedimentation, channel straightening, and stormwater surges that buried the clean cobble walleye eggs need to survive.
Historic phosphorus loading added another blow: heavy algae growth led to deep‑water oxygen loss, which is lethal for incubating eggs and newly hatched fry. By the time phosphorus inputs were reduced, the damage to spawning habitat and early‑life survival had already caused major recruitment failures.
On top of that, fishing pressure in the 1960s–1980s removed a lot of the mature broodstock, leaving fewer adults to rebuild the population.
Then the food web shifted. Zebra and quagga mussels filtered the water and increased clarity, removing the low‑light advantage walleye rely on and giving sight‑feeding predators like smallmouth bass a major edge. Mussels also redirected nutrients to the lake bottom, changing the availability of zooplankton and soft‑bodied prey that young walleye depend on. With bass and perch populations booming, competition and predation on walleye fry increased at the exact time their habitat quality was declining.
Today, walleye are still present in Lake Simcoe, but at very low densities, and natural reproduction remains weak. The science is clear: without restoring tributary spawning habitat, improving deep‑water oxygen conditions, and rebalancing the food web, stocking alone won’t bring the fishery back. The decline of Simcoe’s walleye is a textbook example of how habitat degradation, harvest pressure, invasive species, and food‑web shifts can push a once‑strong population to the margins.