Zebra Mussels & Sea Lamprey in the Great Lakes: Classic Invasive Species

The impacts of zebra mussels (Dreissena polymorpha) and sea lamprey (Petromyzon marinus) in the Great Lakes are textbook examples of invasive species—non-native organisms causing ecological, economic, or health harm.

Zebra Mussels (Arrived ~1986, ballast water)

• Ecological: Filter 1L/day each → clear water but collapse phytoplankton/zooplankton; starve native mussels, fish larvae.
• Economic: Clog intake pipes (power, water, industry); $300–500M/yr control costs.
• Spread: Recreational boats; now in 30+ states.

Sea Lamprey (Entered via Welland Canal ~1920s)

• Ecological: Parasitic on lake trout, whitefish, salmon; each kills 18+ kg fish.
• Economic: Collapsed commercial fisheries (1940s–50s).
• Control: Lampricide (TFM) in tributaries; barriers; pheromone trapping. $20M/yr; 90% suppression.

Common Traits

• No natural predators in new range.
• High reproductive output.
• Tolerant of varied conditions.
• Human-assisted introduction (canals, ballast, release).

Lesson

Prevention (ballast management, pathway regulation) is far cheaper than control. Great Lakes remain vulnerable—Asian carp, quagga mussels, hydrilla loom.