Criminal #1 The Round Goby Facts: Originated in Eastern Europe Now found in many freshwater areas, including parts of Lake Simcoe Mostly found near bottom of shoreline areas Aggressive and can spawn multiple times/season Adults feed on zebra mussels and eggs of other fish

Crimes Round Goby predators are exposed to high levels of contaminants Reduce other fish population due to egg consumption Alters behaviour, feeding habits, and stress levels of other fish due to aggressive nature

Victims Mottled Sculpin and Native Logperch (found in St.Clair River, near London, ON) Ducks, Walleye

Accessory to Crime Most likely came to Canada in ship ballast water Ballast water is required for ship stability

Criminal #2 Zebra Mussels Facts Originated in Russia Now found in many freshwater bodies all over the world; prolific in the Great Lakes (& Lake Simcoe!) Can produce 30,000 up to 1,000,000 eggs/year Management costs estimated to be $250 - $500 million/year

Crimes Can completely cover undersides of docks, entire boat motors, and anchors Can grow so densely they’ve been known to completely cover populations of native mussels Can also clog water intake pipes for municipalities and hydroelectric companies, and can completely cover water current meters Positive – are very efficient water cleaners (due to filter feeding)

Victims Diporeia Whitefish, Smelt, Sculpin (again!) due to declining Diporeia

Accessory to Crime Most likely came to Canada in ship ballast water Is now spread unintentionally by people, as larvae are microscopic and are very hardy

Other notorious criminals Sea Lamprey

Purple Loosestrife

Asian Longhorned Beetle

European Starling