Welcome to GLANSIS — an inter-agency, Great Lakes-specific database for Aquatic Nonindigenous Species (ANS) information!

The Great Lakes is one of the most heavily invaded aquatic systems in the world, and while some aquatic nonindigenous species (ANS) have had benign or beneficial impacts, others threaten the economy, the environment, or human health and are thus referred to as "invasive". Protecting the Great Lakes ecosystem, regional economy, and community well-being from ANS requires effective prevention, early detection, rapid response, management and control efforts, which in turn is dependent upon the quantity and quality of accessible information. In this effort, GLANSIS serves as the Great Lakes' "one-stop shop" that centralizes and synthesizes the best available information to support effective management and control strategies that limit the introduction, spread, and impact of ANS in the Great Lakes.

GLANSIS is comprised of three species lists: currently established nonindigenous species, species who are expanding past their native range within the Great Lakes or are cryptogenic (Range Expanders), and species that are likely to be introduced in the future (Watchlist). The database provides users with access to:

  • Fact sheets (click for one on Rusty Crayfish, as an example) with information on the identification, distribution, ecology, current regulations, and control methods for each documented ANS, Range Expander, and Watchlist species. NOAA's risk and impact assessment scores and rationales for each established ANS and Watchlist species are included on the fact sheets as well
  • Species lists by basin or subbasin that can be generated and modified based on user-selected criteria
  • A Map Explorer that allows users to view/compare species distributions, develop time-series maps, and overlay ANS distributions with Great Lakes Aquatic Habitat Framework (GLAHF) GIS layers.
  • Downloadable data of georeferenced species' distributions (on the Map Explorer) and species lists (via the list generator) specified by the user's criteria

New to GLANSIS — Users can search for aquatic nuisance species in specific subwatersheds via the Map Explorer. In the "Region to Search" field, choose "Specific HUC regions" and type in 8-digit HUC(s) of interest in the provided field.
About the Database
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Additional Resources

Reporting a new invasive species sighting

The quality of our distribution maps depends on reports from the field! If you are aware of a species present at a location not shown on our maps, please send us a report.


Initial support for the creation of GLANSIS was provided by the NOAA Great Lakes Environmental Research Laboratory (Ann Arbor, MI), the NOAA Invasive Species Program (Silver Spring, MD), and the Great Lakes Fishery Trust (Lansing, MI) ~2002-4. The GLANSIS project has received funding from USEPA under the Great Lakes Restoration Initiative (GLRI) in 2010, 2011, and 2016. GLANSIS is maintained by the NOAA Great Lakes Environmental Research Laboratory.