GLANSIS Database Keeps Tabs on Biological Invaders
The Great Lakes are one of the most unique freshwater ecosystems in the world – but are also heavily threatened by biological invaders. Aquatic invasive and nuisance species are the plants and animals from other regions of the globe that accidentally get brought to the Great Lakes, potentially destroying the local ecosystem. Many species pose a significant threat to the Great Lakes environment and economy, from sea lamprey that devastate prized fisheries, zebra mussels that encrust underwater infrastructure, and aquatic weeds that entangle boat motors and swimmers alike. There are nearly 200 nonindigenous aquatic species currently present in the Great Lakes, many of which have significant environmental and socioeconomic impacts, and keeping track of them across the region is a daunting task. The Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS) is designed to meet this challenge, providing a “one-stop shop” for comprehensive information about aquatic invaders.
GLANSIS is based out of NOAA’s Great Lakes Environmental Research Laboratory (GLERL) and is the Great Lakes hub of the USGS Nonindigenous Aquatic Species (NAS) database. According to Acting GLERL Director Dr. Jesse Feyen, “GLERL experts have long studied the impacts of current and potential invaders in the Great Lakes. As the long-standing home for GLANSIS, our goal is to get the message out about the significant risks they pose.” With funding from the Great Lakes Restoration Initiative (GLRI), the site provides the best available information to limit the introduction, spread, and impact of aquatic invasive species in the Great Lakes. GLANSIS provides a comprehensive set of tools including species profiles, a custom-generated list of invaders, a mapping tool, risk assessments, and more. While GLANSIS was originally designed for use by scientists and environmental managers, this publicly-accessible tool is used by teachers, students, anglers, property owners, and anyone who wants to learn more about stopping invasive species in the Great Lakes. Citizens and stakeholders can help protect their local waterways by learning how to recognize, report, and stop the spread of aquatic invasive species.
The Great Lakes’ Most Unwanted
As of 2025, GLANSIS maintains species profiles of 192 nonindigenous aquatic species that are successfully reproducing and overwintering in the Great Lakes, including fish, plants, invertebrates, algae, and even parasites and diseases. GLANSIS conducts a thorough risk assessment process on all species which facilitates direct comparisons of their impacts, as shown in a recent paper on the top 10 most impactful invaders published in the Journal of Great Lakes Research.
GLANSIS also hosts data on “watchlist” species – plants, animals, and pathogens that have not yet established lasting populations in the Great Lakes, but have been identified by experts as emerging threats. These include invasive silver and bighead carp, which have caused devastating ecological impacts to native fish and plants as they have expanded through other US waterways, as well as aquarium plants and pets like the self-cloning marbled crayfish, where even a single individual can launch a new invasive population.
The GLANSIS team recently brought together more than a dozen invasive species experts for a real-time virtual review to provide new data on more than 50 non-native species that are either already present in the Great Lakes basin or have been identified as an emerging threat. These efforts ensure that the information in the database remains accurate, timely and relevant to environmental managers, educators, and other user groups who rely on GLANSIS for decision-making about aquatic invasive species.
To learn more about GLANSIS and explore the database yourself, visit https://www.glerl.noaa.gov/glansis/ or contact GLANSIS Program Manager Rochelle Sturtevant at rochelle.sturtevant@noaa.gov.