Invasive Zebra Mussels

Posted: September 2014

INVASIVE ZEBRA MUSSELS

A State-wide regulation enforced by the Texas Parks and Wildlife Department requires boaters to drain water from watercraft when approaching or leaving public waterways. The reason? Zebra mussels.

Zebra mussels originated in Russia, spread to the United States in the 1980s and within 10 years colonized the Great Lakes and the Mississippi, Tennessee, Hudson and Ohio River basins. They became established in Texas in Lake Texoma in 2009 and have since been found in the Brazos River Basin, Lake Belton in Bell County, Bridgeport, Lavon, Lewisville and Ray Roberts. In other words, they reproduce rapidly.

Their larvae are microscopic, and the adults are usually less than 1 1/2 inches long. Zebra mussels are usually found in large clusters, have a salient zebra-like striped pattern on their shells, and lie flat on a smooth surface, unlike many other mussels. According to the online National Atlas of the United States, "Once zebra mussels become established in a water body, they are impossible to eradicate with the technology currently available."

The Zebra Mussel is one of the most economically damaging aquatic organisms to invade the United States. Its destructive power lies in its sheer numbers and its ability to attach itself to solid objects such as water intake pipes, water control systems, boat hulls, propellers, trailers, submerged rocks and vegetation, and even other aquatic organisms. Zebra Mussels can smother native mussels and crayfish by accumulating on the shells. Numbers have been reported in excess of 75,000 per square foot. Zebra Mussels potentially pose a multibillion dollar threat to industrial and public water supplies. The ecological impacts of Zebra Mussels can be severe. Zebra Mussels feed by filtering water and removing nutrients. These nutrients are vital to the growth and survival of all other aquatic organisms The state-wide rule requires the "draining of livewells, bilges, motors, and any other receptacles or water-intake systems coming into contact with public waters," according to a release from the department. The release states that additional rules about bait and competitions are set to apply to all watercraft, including personal watercraft, sailboats and kayaks. The rule can be found here, or on the TPWD website. According to Texas Invasives, possession or transportation of zebra mussels is a class C misdemenor for the first offense carrying a fine of up to $500. Repeat offenders could face a class B misdemenor, a fine of up to $2,000, up to 180 days in jail, or both. TPWD was authorized to make this rule after H.B. 1241 was passed in the state legislature. TPWD enacted the rule at the May 22 TPWD commission meeting. To prevent the spread of Zebra Mussels Lake Lavon asks you to complete the following: Recommended precautions include:

 Run your boat at high speed for 10-15 minutes just prior to leaving the lake. Zebra Mussels may be washed off at speeds exceeding 5 mph and larval Zebra Mussels will be flushed from the cooling system.

 Remove any visible vegetation from boat, motor, trailer, and any equipment in contact with the water.

 Inspect equipment for presence of Zebra Mussels immediately upon leaving the lake. If you find Zebra Mussels attached, wash with hot water (140˚) or air dry for at least 5 days before returning to the water. If equipment feels gritty to the touch, young microscopic Zebra Mussels may be attached. Power sprayers will detach Zebra Mussels.

 Drain all bilge water, live wells, engine water, and bait buckets before leaving the lake. Empty bait buckets on land. Never release live bait in the water.

 Flush engine cooling system, live wells, and bilge with hot water. Water hotter than 110˚ will kill larvae and hotter that 140˚ will kill adults

 Air-dry your boat and other equipment for 5 days before using in non-infested waters.

 Boaters and anglers can also help by reporting sightings of suspected zebra mussels to the Texas Parks and Wildlife Department at (800) 792-4263.

Addition information can be found at http://www.texasinvasives.ogr and http://www.tpwd.texas.gov/huntwild/wild/species/exotic/.