INVASIVE EXOTICS

Alewife

Alewife Invaded Great Lakes – used Welland Canal to bypass Niagara Falls. Reached peak abundance in Great Lakes in the 1950s and 1960s No top predator because of lake trout dye-off by sea lamprey Seasonal Dye-offs – GROSS Alewives eat baby lake trout keeping numbers down.

Eurasian Watermilfoil

Eurasian Water Milfoil Introduced from Europe and Asia. Is found in many lakes in North America now. Carried from lake to lake by boats Covers the lake surface with algae Competes with other algae and weed.

Fishhook flea

Fishhook Flea feeds on tiny aquatic organisms called zooplankton, which are an important food source particularly for young fish. Fishhook Fleas compete for the same food as native fish. The barbs make it difficult for small fish to eat them, and without a predator, the fishhook flea can multiply into extremely large numbers

Purple loosestrife

Purple loosestrife Purple loosestrife is an exotic species They typically don't have the predators and competitors with which they evolved, and then the plant population grows out of balance Outcompetes and kills off native prairie plants

Round goby

Round goby Gobies eat eggs of other sport fish (Bass, Trout, Walleye) Although gobies belong to a family of fish with a worldwide distribution in both salt and fresh water, they had not been found in the Great Lakes prior to 1990. The round goby first turned up in Lake Superior's Duluth/Superior harbor area in 1995. Presumably, the fish arrived in ballast water discharged by trans-oceanic ships.   Gobies eat eggs of other sport fish (Bass, Trout, Walleye)

Sea Lamprey

Sea Lamprey In their natural habitat, sea lamprey -- like salmon and alewives -- are ocean fish that spawn in fresh water. Arriving via the Welland Canal. From there, they rapidly colonized all of the upper Great Lakes, with especially large infestations developing in Lakes Michigan and Huron. The sea lamprey is an aggressive parasite -- equipped with a tooth-filled mouth that flares open at the end of its eel-like body and sucks on the flesh of other fish

Zebra mussel

Zebra mussel The Zebra mussel (Dreissena polymorpha) is a bivalve mussel native to freshwater lakes of southeast Russia. Zebra mussels get their name from the striped pattern on their shells size of a fingernail, but can grow to a maximum length of nearly two inches. [1] Compete for food with other species – poor food for fish can multiply greatly in numbers

Buckthorn

Indigenous Species A species that is native to a given area

RIVAL FOR SURVIVAL