GLANSIS technical memos add new data to invasive species risk assessments

Memos provide transparent, publicly available documentation of the risk assessment process.

Figure 1 – Grass carp is one of the nonindigenous species for which information is updated in TM161-c.
Figure 1 – Grass carp is one of the nonindigenous species for which information is updated in TM161-c.

With over 180 aquatic nonindigenous species currently present in the Great Lakes and potential new invaders on the horizon, keeping track of the impacts and risks that these organisms pose is an ongoing challenge. The Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS) was designed for this purpose, hosting data on the historical and ongoing effects of aquatic organisms introduced to the region. GLANSIS researchers recently completed annual updates to NOAA Technical Memos (TM-161c and TM-169c), which serve as the risk and impact assessments underlying the content of the online database.

What are the GLANSIS tech memos?

NOAA Technical Memorandum series are used for the timely documentation and communication of raw data, preliminary results of scientific studies, or interim reports that may not have received formal external peer reviews in the style of academic journal articles or manuscripts. These numbered publications are publicly available online in PDF format, and serve as important research documentation and reference material.

The GLANSIS team updates two different tech memos every year by reviewing and synthesizing the scientific literature on invasive -- or potentially invasive -- aquatic species. The first, TM GLERL-161et seq., “An Impact Assessment of Great Lakes Aquatic Nonindigenous Species”, provides the updated impact assessments for nonindigenous species documented as reproducing and overwintering in the Great Lakes, focusing on their ecological, socio-economic, and beneficial impacts to the region. The second, TM GLERL-169 et seq., “A Risk Assessment of Potential Great Lakes Aquatic Invaders documents species that have been identified as likely to become invasive if introduced to the Great Lakes region. The 2019 updates document the updated impact assessments for 89 of the 188 nonindigenous species (TM-161c); and four assessments were updated and eight new species added for potential invasives (TM-169c).

Why are the tech memos updated every year, and why are they important?

The GLANSIS technical memos provide transparent, publicly available documentation of the risk assessment process that underlies the species profiles in the database. Not only does it provide the summary information available on the website, but it provides all the original sources and the details of the specific semi-quantitative analysis behind declaring particular species ‘high impact’. New and improved data on aquatic invasive species is being published all the time, and documenting annual updates to risk and impact assessments helps to keep the GLANSIS database up-to-date and allows researchers to track the changes in the state of knowledge for specific species through the years. Each update takes a new look at how the latest data influences larger-scale patterns and trends. Unlike a website, where old versions are overwritten by the new, the technical memos provide a stable, citable reference point.

The GLANSIS tech memos can be read in full at the NOAA Great Lakes Environmental Research Lab’s publications page. Learn more about GLANSIS at the website or contact Rochelle Sturtevant 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 34 university-based programs.

This article was prepared by Michigan Sea Grant under award NA180AR4170102 from the National Oceanic and Atmospheric Administration, U.S. Department of Commerce through the Regents of the University of Michigan. The statements, findings, conclusions, and recommendations are those of the author(s) and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration, the Department of Commerce, or the Regents of the University of Michigan.

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