Toledo Bend
Bi-State
Alliance

The Louisiana Sea Grant College Program and the Sabine River Authority sponsored a one-day workshop at Toro Hills on Nov. 19 to provide Toledo Bend neighbors and users information on zebra mussels. This small fresh water mussel is creating a multi-million dollar ecological havoc in waters it has managed to invade and now it is almost certain to find its way into Toledo Bend.

This small mussel that ranges in size from about 70 microns to a little over an inch presents the threat of a giant size impact on the Sabine River and Toledo Bend Reservoir.

These small striped mollusks were first introduced into the Great Lakes in the 1980's and have already navigated the Mississippi to areas south of Baton Rouge and into the Atchifalaya Basin. They travel in egg, larvae (veliger) or juvenile form by the natural flow of the river currents or will hitch a ride on the hull of commercial or pleasure boats and barges.

The terrible certainty that they will soon invade the Sabine and Toledo Bend comes from the fact that a perfect route exists into the lower Sabine via boats and barges using the Intercoastal Canal. Their route into Toledo Bend will be by fishing and other recreational boats that visit Toledo Bend or the 14 lakes in the watershed above Toledo Bend.

A boat that has been used in an infected body of water (like the Atchifalaya) may carry the larvae, juvenile or mature mussels in the "live boxes", cooling system or on the hull. A few gallons of water in a "live box" may contain thousands of the microscopic larvae or eggs. Thousands of juvenile mollusks smaller than a grain of sand can cling to the hull and may live out of water for a couple of days.

Why should we be concerned about a few small mussels? With these mussels there is no such thing as "a few". A single female can spawn a million eggs in a year . They build up on any solid surface they may contact and a colony of mussels can grow from 30 mussels per square meter to 400,000 per square meter in a single month. They even cling to the stems of plants such as the hydrilla that has taken over many areas of the lake. They will clog the inlets of water systems and the interior of water pipes. They encrust the hulls and motors of boats. In fact, any firm surface that is not in constant motion is subject to encrustation within a very short period.

In a worst case the mussel build-up in an area can disrupt the food chain of all the biological specimens in a lake. A single mussels may filter an average of three quarts of water per day extracting the tiny zooplankton and phytoplankton that fish larvae depend on and threatening the existence of our fish and other aquatic animals. They also consume the desirable forms of algae necessary as food for zooplankton leaving harmful blue-green algae to proliferate. The blue-green algae is toxic to ducks, fish and other animals.

Since we are threatened by this invasion of the zebra mussels, what can be done to stop them? The answer is that we will not be able to stop them.

We must then take steps to slow the invasion . To do this there must be a stringent system of preventing boats from carrying the animals into Toledo Bend or the streams within the watershed. One of the most probable sources of infestation will be the bass tournaments held on Toledo Bend. Bass clubs and the SRA that play host to these tournaments must assume a responsibility for monitoring boats coming into the area. There should be plans to prevent the use of contaminated boats or to provide a means of sanitizing these boats by wash down and use of molluscicides. Hot water can remove or kill mollusks clinging to boat hulls or motors and a good wash down in a car wash equipped with hot water will be a good deterrent. Individual residents must be careful of using their boats in infested bodies of water. Precaution should be taken to assure that they do not bring the mussels home with them. A good policy is to dry your boat and let it stay out of the water for a few days. Don't bring any water home in your "live box" or bait buckets and be sure you are not bringing home weeds that may be infected by larvae or eggs.

In spite of all precautions we will eventually have this pest as a neighbor. So what do we do to live with them?

There is currently dozens of research programs in Sea Grant Colleges and other laboratories to find methods of protecting power plants, water systems, etc against encroachment from the mussels and to find methods of removing them from boats, barges and other structures. The results of the findings of these researches will be made available to public and private organizations and will be published in articles such as this one.

Submitted by: William B. Lewis, Sabine River Compact Administration

Chairman, SRA Citizens Advisory Committee

President, So. Toledo Bend Civic Association