Invasive Species

What are non-native and invasive species?

The Great Lakes region is rich with life and full of native species well-adapted to survival. However, since the early 1800s, many non-native plants, animals, and microscopic organisms have been introduced into the Great Lakes, either accidentally or intentionally.

Some nonnative species have been harmless or even beneficial for the Great Lakes, such as the introduced salmon that now delight Great Lakes anglers. Many non-native species are considered invasive, as they are free from natural predators, reproduce rapidly, and aggressively compete with native species. Many terms have sprung up to describe these newcomers, including aquatic invasive species (AIS) or aquatic nuisance/non-indigenous/nonnative species (ANS).

Invasive species disrupt the food web by reducing habitat or food for native species and by preying directly upon them. Invasive species can affect property values and influence economies of water-dependent communities. They are costly to manage and have led to a severe loss of biodiversity in Michigan, the Great Lakes region, and throughout the world.

How do they get here?

Aquatic nonnative and invasive species arrive in the Great Lakes through a variety of channels. Many traveled across the ocean in ballast water carried by freighters. Others were released intentionally or accidentally after being brought to the region for bait, gardening, ornamental fish ponds, food, or pets. Some have entered from the ocean through human-built channels such as the Welland Canal.

Which Great Lakes species are invasive?

As of 2018, an estimated 187 non-native species have become established in the Great Lakes since the 1800s. Some, like sea lamprey and zebra mussels, have become household names in the region. The majority receive little press coverage and limited research or management funds. The Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS) is a one-stop shop for information about non-native species in the region. Explore the GLANSIS database and visit the Additional Resources page for the latest versions of the GLANSIS poster of current invaders and watchlist of potential incoming species.

Featured invasive species resources

What can I do?

You are critical in controlling the spread of invasive species. Follow a few simple steps every time you hike, boat, or fish:

  • Learn to identify native and invasive plants and fish.
  • Never release plants, fish, or animals into a body of water unless they came out of that body of water.
  • Remove any visible mud, plants, fish, or animals from anything that came into contact with water, such as boats, trailers, and equipment. Even your clothing, shoes, or dog can transport invasive species.
  • Eliminate water from equipment before moving to another location.
  • Eliminate the use of any wildflower and seed mixtures that have purple loosestrife and other invasive plant seeds. Wildflower mixes should have seed ingredient lists on the packaging.

If you find what you suspect may be an invasive species, report the incident to your local Michigan Sea Grant Extension educator or use the MISIN website or mobile app. Have the following information on hand:

  • Sample (or photo capturing key features) to confirm identification
  • Date collected or observed
  • Location collected or observed (GPS coordinates preferred)
  • Your contact information

For more information about aquatic invasive species, contact Rochelle Sturtevant at or (734) 741-2287.