Memorial Day Weekend marks the opening of summer activities in the Midwest, and summer activities often include spending time on the water. In addition to maintaining safe boating practices, boaters should be aware of ways to prevent the transportation of nonindigenous species, those plants and animals not native to the region.

Zebra mussels have moved out of the Great Lakes into inland waterways. These tiny mollusks attach themselves to boats and fishing equipment, and their free-swimming young can live in standing water found in bait buckets and engine cooling systems. As boats are moved about, zebra mussels are often unknowingly transported from one body of water to another.

Zebra mussels were transported from Europe in ballast water of ships and were found in the Great Lakes in 1986. The tiny mussels form large clusters that can clog water lines. Damage can occur in boat engines if cooling systems are clogged. These clusters present costly threats to industries, municipal water plants and agricultural irrigation systems.

Illinois-Indiana Sea Grant nonindigenous specialist Pat Charlebois noted that clean-up costs and control associated with zebra mussels are significant. Charlebois said, "Great Lakes industries and municipal water firms spent an estimated $120 million in clean-up costs in one five-year period following the zebra mussel invasion."

Boaters can help slow the spread of zebra mussels by following a few simple steps:

• Inspect boats, trailers and boating equipment and remove any visible plants or animals.
• Drain water from the motor, livewell, bilge and transom wells while on land before leaving any waterbody.
• Empty bait buckets on land before leaving the waterbody. Never release live bait into a waterbody. Do not release aquatic animals from one waterbody into another.
• Wash/dry boats, tackle, downriggers, trailers and other boating equipment to kill harmful species not visible. This task may be done on the way home or after arrival. Some aquatic nuisance species can survive more than two weeks out of water, so it is important to do one of the following:
  • rinse boats and equipment with hot water (40C or 140F )
  • spray boats and trailers with high pressure water
  • dry boats and equipment at least five days before transporting to another water body

Zebra mussels also harm native species. In addition to clustering onto native mussels, zebra mussels filter phytoplankton and zooplankton, small plants and animals living in the water. This activity affects the food supply for native species.

Sea Grant research and education has helped reduce the harmful effects and associated costs of the spread of zebra mussels. Illinois-Indiana Sea Grant activities have included the following:

• a regional conference in St. Louis in 1996 for inland industrial and municipal water users
• a session at the annual Zebra Mussel and Aquatic Nuisance Species Conference in New Orleans in January 1997
• prevention session at the May 1997 Illinois Lake Management Association Annual Conference
• prevention session at the April 1997 Indiana Lake Management Conference
• a teaching tool for educators, "Zebra Mussel Mania Traveling Trunk" that may be borrowed at several locations
• a teleconference, "Zebra Mussels: Lessons learned in the Great Lakes," is scheduled for September 10, 1997.

Other nonindigenous species including ruffe and round gobies have the potential for economic and ecosystem threats to the southern Lake Michigan region. Charlebois said, "Several nonindigenous species that have been introduced into Lake Michigan have had significant effects on native species. The potential for further introductions and the possible harm associated with them must be recognized. Continued efforts of all citizens are extremely important to reduce further spread."

For more information, contact Illinois-Indiana Sea Grant nonindigenous specialist Pat Charlebois, 847 872-0140 or charlebo@illinois.edu

Irene Miles
Illinois-Indiana Sea Grant
376 NSRC
1101 W. Peabody Dr.
Urbana, Il 61801
Phone:  217-333-8055
Fax:  217-333-8046
miles@illinois.edu