Zebra mussel larvae, known as veligers, have been confirmed in Lake Bridgeport. The news comes days after the discovery of the invasive exotic in Lewisville Lake.
A zebra mussel population is suspected in Lake Bridgeport because zebra mussel DNA was found in the fall of 2011 and 2012, and some veligers were detected this spring in plankton tows. Samples collected by the Tarrant Regional Water District (TRWD) from Lake Bridgeport on June 6 were examined using cross polarized light microscopy and suspect veligers were detected. Dr. Bob McMahon with The University of Texas-Arlington (UTA) confirmed these results on June 17.
It is important to note that to date no settled juvenile or adult zebra mussels have been found in Lake Bridgeport to suggest a self-sustaining population. Given the high mortality rates of zebra mussel veligers it’s not a guarantee that a population exists but given these results and the DNA results from the past two years it is likely that the lake is infested.
Routine monitoring by the TRWD, UTA and Texas Parks and Wildlife Department (TPWD) will continue on the reservoir to determine if there is any growth or spread of the mussels. Also, because lakes Eagle Mountain and Worth are downstream of Lake Bridgeport they are also at risk and will continue to be monitored.
Zebra mussels can have economic and recreational impacts in Texas reservoirs. They can clog public-water intake pipes, harm boats and motors left in infested waters by covering boat hulls and clogging water-cooling systems, annoy boat-dock owners by completely covering anything left under water and can make water recreation hazardous because of their razor-sharp edges.
From the environmental perspective, zebra mussels are filter feeders, which mean they compete with baitfish such as shad for available forage. Any impact on baitfish in turn can affect their predators — game fish such as bass, striped bass and catfish. Zebra mussels are also very harmful to native mussel populations because they will colonize on their shells and essentially suffocate them.
The spread can be slowed by making sure boats that operate in zebra mussel-infested waters are not used in any other body of water until they have been cleaned, drained and dried. In addition, TPWD adopted rules regarding the transfer of zebra mussel larvae in water from lakes Texoma, Lavon, Ray Roberts and Lewisville. To comply with these rules, boaters and anglers need to drain all water from their boats (including live wells) before leaving those lakes.
TPWD and a coalition of partners have been reaching out to boaters in Texas with an advertising campaign to educate them not to transport the tiny mussels or their microscopic larvae, which are invisible to the naked eye and can stay alive inside livewells, bait buckets and other parts of the boat for up to a week. These partners include: Tarrant Regional Water District,North Texas Municipal Water District, Trinity River Authority, City of Dallas Water Utilities Department, Upper Trinity Regional Water District, Sabine River Authority, Canadian River Municipal Water Authority, San Jacinto River Authority, Brazos River Authority, City of Grapevine, City of Houston, City of Waco and Lady Bird Johnson Wildflower Center.
Originally from the Balkans, Poland and the former Soviet Union, zebra mussels found their way to the Americas in the 1980s via ballast water of a ship. The small invaders were first found in 1988 in Lake St. Clair, Mich., and are currently known to have infested 29 states and more than 600 lakes or reservoirs in the United States.
Anyone wishing to receive a supply of informational brochures, wallet cards or posters about zebra mussels to distribute to boaters around lakes Bridgeport, Lewisville, Ray Roberts or Texoma, please contact firstname.lastname@example.org. For more information regarding zebra mussels visit www.texasinvasives.org.
SOURCE and LINK:
Texas Parks and Wildlife Department