Great Lakes Article:

Zebra mussels threaten Missouri
By the Missouri Department of Conservation
Published in the Jefferson City News Tribune on:
June 30, 2005

Every year, zebra mussels inch closer to Missouri's borders.

So far the Show-Me State hasn't documented an infestation of the striped invaders. However, that could change overnight if boaters, anglers and marina owners are not careful. The rewards for watchfulness include continued enjoyment of clean water, pleasant beaches and good fishing.

Zebra mussels, which are native to the Caspian Sea, found their way to into the St. Lawrence Seaway in the ballast tanks of ocean-going ships in the mid-1980s. It took them just five years to gallop across the Great Lakes. Then they jumped from southern Lake Michigan into the Illinois River. By 1991 they had reached the Mississippi River. Since then, they have hitched rides to other North American waters in anglers' bait buckets and on pleasure boats and commercial craft. Live zebra mussels have even been found attached to trailered boats in California.

Zebra mussels are amazingly prolific, covering any available solid surface with thousands of individual animals per square foot. They can cause increased utility bills when they clog water intake pipes of power generating plants, municipal water plants and other utilities. They also damage boats, docks, buoys and other property on lakes and rivers.

Removal is possible, but expensive. Industries around the Great Lakes spend an estimated $3 million per year to remove the mussels from their operating systems.

Zebra mussels can attach to power boats' drive units and clog water intakes, causing damage to engines. They feed on plankton, the microscopic plants and animals that form the basis of the aquatic food chain. This puts them in direct competition with native mussels and young fish, including bass, bluegill and other popular sport fish.

State and federal agencies have spent millions of dollars seeking ways to eradicate zebra mussels, but so far nothing has been found to eliminate them without harming other, desirable animals.

Oklahoma officials have confirmed the presence of zebra mussels in Grand Lake. One of the lake's tributaries, Elk Creek, enters Oklahoma from southwest Missouri. Adult zebra mussels and larvae also have been found at El Dorado and Cheney lakes on the east and west sides of Wichita, Kan. Adult zebra mussels also have been found in the Missouri River at Sioux City, Iowa.

Steve McMurray, a resource scientist with the Missouri Department of Conservation, said alert citizens have played a key role in preventing zebra mussel infestations in Missouri so far.

"One of our strongest lines of defense has been marina operators," McMurray said. "We have caught several infested boats before they went into Missouri lakes and streams because marina personnel knew what to look for and alerted us to the problem."

Boat owners appreciate help, says McMurray. Once they realize that launching an infested boat could hurt fishing, they are glad they found out in time.

Preventing the spread of zebra mussels isn't difficult, but it requires attention. Just as ocean-going vessels carried the invaders from Europe, pleasure craft can harbor microscopic zebra mussel larvae in live wells, engine cooling systems, bilge pumps or bait buckets. Once released into uninfested waters, the animals grow and multiply unchecked.

Missourians can slow the spread of the zebra mussel by draining all bilge water, live wells, bait buckets and any other water from their boats and equipment before moving from one body of water to another.

Boaters should dispose of leftover live bait and should inspect boat hulls, drive units, trolling plates, prop guards, transducers, anchors and trailers, and then scrape off and trash any suspected mussels, however small. They should also remove all water weeds from boats and trailers and flush boat hulls, drive units, live wells, bilges and their pumping systems, trailers, bait buckets, engine cooling water systems and anything that got wet with a hard spray from a garden hose.

If your boat and trailer were in infested waters, take them through a carwash and clean them with hot, high-pressure water. Dry boats and trailers in the sun for two to four days before taking them to new areas.

Running boats frequently helps reduce zebra mussel infestation. Small juvenile mussels are soft and are scoured off the hull at high speeds. If possible, avoid leaving outboard motors or the drive units of inboard motors in the water when not in use. Hulls and drive units should be inspected periodically and scraped free of mussels. Pumping hot water through engine intakes prevents zebra mussel growth in the cooling system.

Zebra mussel sightings should be reported to the nearest Conservation Department office. You can find information about what to look for in the "Summary of Missouri Fishing Regulations," available wherever fishing permits are sold, or request "Zebra Mussels: Missouri's Most Unwanted" from Conservation Department Distribution Center, P.O. Box 180, Jefferson City, Mo., 65102-0180, phone (573) 522-4115, ext. 3630, pubstaff@mdc.mo.gov. The information is available online at www.mdc.mo.gov/nathis/exotic/zebra/.