In September I posted information on Texas Parks and Wildlife Department Commission's ongoing efforts to combat the spread of invasive zebra mussels. The Commission approved for public comment new proposed rules requiring that all boats operating on public water in 17 Northeast Texas counties be drained after use. Zebra mussels became established in Texas in Lake Texoma in 2009. Last year, they were found in Lake Ray Roberts and the Elm Fork of the Trinity River. Zebra mussels had spread to Lake Bridgeport on the West Fork of the Trinity River and into Lake Lewisville. The rapidly reproducing mussels, originally from Eurasia, can have serious economic and recreational impact to Texas reservoirs. They can clog public-water intake pipes, harm boats and motors left in infested waters by covering boat hulls, clog water-cooling systems, annoy boat-dock owners by completely covering anything left under water, and make water recreation hazardous because of their sharp edges. From an environmental perspective, zebra mussels are filter feeders which means 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. On last Thursday the TPWD Commission voted to make permanent the emergency requirements for boaters to clean, dry and drain permanent rules for public waters in Collin, Cooke, Dallas, Denton, Fannin, Grayson, Hood, Jack, Kaufman, Montague, Palo Pinto, Parker, Rockwall, Stephens, Tarrant, Wise, and Young counties. Most recently zebra mussels were discovered Sept. 18 in Belton Lake, 60 miles north of Austin. It was the first time zebra mussels have been documented in the Brazos River basin, nearly 200 miles south of where they had been found previously in Texas. As a result, the Parks and Wildlife Department issued an emergency "wash, dry and drain" order in September for Belton Lake, Stillhouse Hollow Lake, and the Leon and Lampasas rivers. Texas Parks and Wildlife Department staff will begin drafting regulations extending to Bell and Coryell counties in Central Texas, said Ken Kurzawski, freshwater fisheries regulation coordinator for the Parks and Wildlife Department. The proposal will probably be published for public comment in December and go before commissioners in January.