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GIS Map Gallery: December 2004


Zebra Mussel Map

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Zebra Mussels

In September 2002, the Virginia Department of Game and Inland Fisheries (VDGIF) confirmed that a zebra mussel population was present in Millbrook Quarry, which is located in western Prince William County. While zebra mussels were discovered and removed from a boat at Smith Mountain Lake in 1993 before it was launched, a population had never before been documented in Virginia. Native to the Caspian, Black and Azov seas of eastern Europe, zebra mussels are believed to have been introduced into U.S. waters in 1986 through ballast water discharge in the Great Lakes. As the following map depicts, these invasive mollusks have spread rapidly throughout most of the Great Lakes and Mississippi River Basin states and now inhabit water bodies in or bordering 25 states. Unlike other freshwater bivalves, zebra mussels can attach to surfaces using their byssal threads, leading to tremendous recreation, wildlife, and economic damage. Zebra mussels can colonize or clog watercraft hulls and motors; smother aquatic wildlife like freshwater mussels and crayfish; and encrust pilings, dams, pipelines, or water treatment facilities. In fact, many water and power facilities in infested areas must regularly treat their systems to keep them free of this exotic species. Additionally, zebra mussels are efficient filter-feeders and can remove microscopic organisms that make up the food base for many native fishes and aquatic wildlife. Given their ability to attach to hard surfaces and survive out of water for up to 7 days, many infestations have occurred by hitching rides on watercraft. The microscopic larvae also can be transported in bilges, ballast water, live wells, or any other equipment that holds water. Because of the potential environmental and economic impacts of zebra mussels, VDGIF is counting on you to help stop the spread of this invasive species by taking the following precautions:

  • Visually inspect and scrub boat hulls, motors, anchors, and trailers, removing any attached vegetation at site of origin; then hose equipment with hot (140F) and/or high-pressure water if possible
  • Bilges, live wells, and any other water-holding compartments should be drained at the site of origin and flushed with disinfectant or hot water
  • Temperature- or chemical-sensitive equipment such as SCUBA gear should be visually inspected and cleaned, and soaked in a solution of ½ cup salt per gallon water, then carefully rinsed.
  • After treatment as above, boats, waders, bait buckets, and other equipment should remain completely dry for at least 24 hours before being used again

The Department is soliciting proposals to eradicate the zebra mussel infestation in northern Virginia. If you believe you have seen or found a zebra mussel, please contact VDGIF immediately at (804) 367-6913 or Brian Watson at VDGIF's Lynchburg office (434-525-7522). For more information on zebra mussels, please see VDGIF's website.

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