The effect of the zebra mussels is to reduce the food source for microscopic zooplankton which is the base of the food web. This effects invertebrates which then impacts forage fish which in turn impacts game fish. Kelpinger also described the effect of purple loosestrife, a native of Europe and Asia. It s an attractive plant that has been sold in nurseries. It grows to between four and seven feet and proliferates in wetlands.
Purple loosestrife takes over native vegetation forming a monoculture.
As the native plants are reduced, so too are the wildlife species that depend on them. Dense stands of purple loosestrife also impair recreational use of wetlands and rivers and impede water flow. He briefly covered the Eurasian watermilfoil and the ruffe. Regarding the ruffe, he noted that use of chemical barriers has been planned in the Lake Superior region but not implemented. Ruffe populations can be very prolific and they can feed on walleye and perch and cause a large impact to the fishery.