Saturday, March 24, 2018
Getting a jump on Aquatic Invasive Species

Getting a jump on Aquatic Invasive Species

Great Lakes Risk Assessment Tools

by Anjanette Riley, Illinois-Indiana Sea Grant

The aquatic plant, yellow floating heart

The aquatic plant, yellow floating heart

Invasive species like yellow floating heart have crowded out native vegetation in aquatic habitats across the Great Lakes states. Credit: Smithsonian Institution

The Great Lakes may span eight states and two provinces, but the threat of new aquatic invasive species is a constant reminder that the region is connected in more than name alone. In the past, invasive species like zebra mussels, Asian carp, and hydrilla have hitched rides in ballast water and on boats or have been transported across the region to be sold in new markets. These invaders can disrupt aquatic food webs, block out sunlight needed by other species, and hinder commercial and recreational fishing. And each jurisdiction can do little to curb the spread alone.

“These invasive organisms don’t stop at the border,” said Reuben Keller, an environmental scientist at Loyola University Chicago. “If they are introduced into one part of the region, they will reach every state. Everyone’s risk level is the same as the least regulated state.”

Now, a new initiative is providing resource managers with the information they need to develop consistent policies tackling one vector through which species enter new habitats: trade. The effort focuses on the development of risk assessment tools that can be used to determine which commercially sold plants, fish, mollusks, crustaceans, reptiles, and amphibians are most likely to survive and spread across the Great Lakes.

Water lettuce

Water lettuce

Found in the Great Lakes basin in 2011, water lettuce has been flagged as a high-risk invader. Credit: University of Georgia’s Center for Invasive Species and Ecosystem Health

A collaboration of University of Notre Dame researchers, invasive species experts, and outreach specialists from the Illinois-Indiana Sea Grant are producing a single set of tools to evaluate species based on factors such as the ability to survive in Great Lakes conditions and how difficult the species is to control. Regular working meetings with resource managers will ensure the finished products are useful. The tools and trainings are expected to be completed in 2014.

“We will also be talking with retailers, hobbyists, and water gardeners—going to shows and posting information in stores—about how they can use the risks assessments as a guide to get ahead of regulations and make responsible decisions now,” said Pat Charlebois, Illinois-Indiana Sea Grant’s aquatic invasive species coordinator.

Officials will be able to use each tool to set policies targeting species that pose the greatest threat to the lakes. Included on the list is water lettuce, which choked hundreds of waterways in southern states before its discovery in the Great Lakes basin in 2011. In some jurisdictions, these would be the first rules regulating species in trade.

Row of aquarium tanks

Row of aquarium tanks

New risk assessment tools pinpoint aquarium plants and fish with a high risk of invasion in the Great Lakes region. Credit: Illinois-Indiana Sea Grant

It may be difficult for states and provinces with different existing policies to implement entirely uniform regulations. However, these tools could help the 10 states and provinces agree on a minimum level of protection, ensuring that species ranked as likely invaders could not be sold in any jurisdiction. Slowing the spread of aquatic invasive species in this way would be significant not only for the ecosystems and economies of the region, but for the U.S. and Canada as a whole, since the Great Lakes has proven in the past to be a launching point for the spread of invasive species.

“Preventing future commercially-sold aquatic invasive species from escaping into our waters is the most cost-effective management tool,” said Eric Fischer, aquatic invasive species coordinator for the Indiana Department of Natural Resources. “Indiana has already been able to use the aquatic plant risk assessment tool to ban 28 invasive plants from sale, trade, and dispersal within the state.”

Even without new regulations, the tools could reduce the spread of new and existing invasive species by helping people avoid buying and selling potential aquatic invaders, and unite them under the common goal of preserving their Great Lakes ecosystems.