ABSTRACT
ABSTRACT A cost-effective zebra mussel (Dreissena polymorpha) risk assessment and monitoring/ early detection system speci‘cally designed for Texas and other southwestern United States water bodies was conducted at 14 Texas lakes during spring and fall 2011 and spring 2012. The water bodies included zebra mussel-infested Lake Texoma (Grayson and Cook counties) and 13 zebra mussel-uninfested water bodies: Lake Arrowhead in the Red River Basin; Lakes Bridgeport, Eagle Mountain, Lewisville, Lavon, Ray Hubbard, and Ray Roberts in the Trinity River Basin; Lake Wright Patman in the Sulfur River Basin; Lakes Tawakoni and Fork in the Sabine River Basin; and Lakes Bob Sandlin, O’ the Pines, and Caddo in the Cypress River Basin. Invasion risk assessment was based on published tolerated limits of oxygen saturation, pH, calcium concentration, and upper temperature limits in southwestern zebra mussel populations. Monitoring consisted of cross-polarized light microscopic examination and quantitative polymerase chain reaction (qPCR) testing for mussel DNA in concurrent vertical-tow, near-shore plankton samples along with mussel settlement on scouring pad monitors conducted from marina or privately owned docks, eliminating the need to sample from boats. Five of the water bodies, including infested Lake Texoma, were assigned a high risk for successful invasion as all four tested risk parameters
Introduction ............................................................................................................................................ 350 Invasion of United States Water Bodies by Zebra Mussels .............................................................. 350 Zebra Mussel Invasion of Lake Texoma (TX/OK) ............................................................................351 Invasion Risk to Other Northeastern Texas Water Bodies .................................................................352
Methods ...................................................................................................................................................353 Water Bodies Chosen for Zebra Mussel Invasion Risk Assessment and Monitoring ........................353 Invasion Risk Assessment for the Monitored Lakes ..........................................................................353 Zebra Mussel Settlement Monitoring ............................................................................................... 357 Plankton Sampling for Zebra Mussel Veliger Larvae ....................................................................... 358
Results and Discussion .......................................................................................................................... 359 Zebra Mussel Invasion Risk Assessment .......................................................................................... 359 Monitoring for Zebra Mussel Invasion of Northeastern Texas Water Bodies ................................... 362
