By analyzing data researchers can close that knowledge gap by identifying patterns and trends across entire classes and families of organisms: valuable information in a constantly-changing ecosystem like the Great Lakes.
Of the more than 185 nonindigenous aquatic species present in the Great Lakes region, nearly one-third are plants. Aquatic plants play a major role in their environments by providing food and habitat for fish and other animals, oxygenating the water, limiting erosion, and more — but the introduction of invaders can throw off the balance of the aquatic habitats they help sustain. A new publication from the Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS) team shows how 55 species of introduced plants may crowd out, smother, poison, or otherwise out-compete plants native to waterways within the Great Lakes basin.
Aquatic plants form a unique subset of the Great Lakes invasion history. Bluntleaf dock was the first nonindigenous aquatic plant introduced to the Great Lakes basin around 1837, and most plants were introduced prior to 1920. Unlike the fauna, most were deliberately introduced or came as contaminants with other products rather than through ballast water from ships.
Analyzing the effects
By analyzing data available through the GLANSIS database, researchers were able to re-examine the effects of multiple species at the same time to gain a fuller picture of both this history of invasion and how nonindigenous aquatic plants impact native aquatic plants.
The paper highlights the diverse adaptations that give invading plants like purple loosestrife, phragmites, and Eurasian watermilfoil their competitive edge in Great Lakes habitats. In fact, adaptations that have been previously found to aid successful invasions, like a high tolerance for environmental contamination or the ability to shade out other competing species, were commonly found in 98% of the nonindigenous plants established in the Great Lakes. This synthesis showed that many of these nonindigenous plants have notable negative impacts on the native plant communities of the region in general, and especially on species of concern.
Still much to learn
Although nonindigenous aquatic plants have been documented throughout the Great Lakes for nearly two centuries, a great deal remains unknown about the impacts of their competitive behavior and adaptations. By analyzing GLANSIS data, which itself is synthesized from both historical and cutting-edge scientific literature, researchers can close that knowledge gap by identifying patterns and trends across entire classes and families of organisms: valuable information in a constantly-changing ecosystem like the Great Lakes.
“A Review and Secondary Analysis of Competition-Related Impacts of Nonindigenous Aquatic Plants in the Laurentian Great Lakes” is available to read as an open-access article in a special issue of Plants focused on competition between native and invasive plants worldwide.
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.