Database provides a diverse toolkit for the fight against aquatic invaders

Learn how to use the online List Generator to find what species have become established in your watershed.

With its ability to generate species lists by watershed, show sightings on a map, display collection records, and serve detailed information on nonindigenous species throughout the Great Lakes Basin, the Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS) database provides a diverse toolkit for the fight against aquatic invaders. In this article, we’re focusing on one of the site’s primary functions, the List Generator, and how to use it.

What is the List Generator?

The List Generator does exactly what its name suggests: it allows users to look up custom lists of nonindigenous species in the Great Lakes region by taxon, status, vector of dispersal, or the basin in which they’re found. Every species provided in these generated lists has an accompanying profile which features information on their identification, ecology, range, risk assessment scores, and management. This tool is ideal for providing an overview of which species live in the specific watersheds that make up the Great Lakes basin, and provides easy access to comprehensive information about the individual species in question.

How do I use the List Generator?

How you use the List Generator depends on the type of information you’re looking for. Say, for instance, you want to pull up a list of all non-native fish currently established in Lake Michigan. To do so:

  • Specify “Nonindigenous + Range Expanders” in the Species Category box,
  • “Fishes” in the Group box,
  • “Lake Michigan (4060200)” in the Lake (HUC) box,
  • and “Established” in the Status box, then hit Submit.


The search results include the images, scientific and common names, continent of origin, year first collected, status in selected watersheds, and category for each of the individual species identified. Clicking the scientific names will take you to the technical species profile, while clicking the common names for some select species will take you to a non-technical profile written in plain language suitable for a fourth-grade reading level and above.



Watershed-specific searches can be conducted down to a fairly local level. We use the national Hydrologic Unit Code cataloging units (HUC8) to define watersheds. You can locate your watershed using USGS’s “Science in Your Watershed” tool at Click on your geographic area to access your watershed. Clicking again on the next map will give you a more detailed breakdown of your watershed.

To use this tool in GLANSIS:

  • Select ‘Custom’ under the Lake (HUC) selector.
  • This pulls up a secondary selector where you can enter your watershed code (leave off the initial ‘0’). For example, you can generate a custom list of species found in one particular section of the River Raisin, a river in southeastern Michigan, as shown in the example below.



Once you have the short list for your watershed, you can access map data for each species by:

  • Clicking on the scientific name
  • Scroll to the map
  • Click the link just below the map which reads “Click here for Great Lakes region collection information.” When you are in the custom mode, this returns only the data for the watershed you originally selected. This allows you to quickly see whether a particular species has been reported for your lake.



To try using the List Generator yourself and learn more about the nonindigenous species in your local waterways, go to

For more information on the List Generator, or GLANSIS as a whole, please contact Rochelle Sturtevant at or El Lower at

Michigan Sea Grant helps to foster economic growth and protect Michigan’s coastal, Great Lakes resources through education, research and outreach. A collaborative effort of the University of Michigan and Michigan State University and its MSU Extension, Michigan Sea Grant is part of the NOAA-National Sea Grant network of 33 university-based programs.

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