A campaign urging boaters and fishermen to avoid "hitch-hiking" aquatic plants and crustaceans has been kicked off by the South Carolina Department of Natural Resources.
Large, bright yellow signs have been posted at more than 60 boat landings throughout the state reminding boaters to clean their boats, propellers, aerated live wells and trailers when moving from one lake or river to another.
"Many exotic plant species reproduce by fragmentation and spread rapidly," said Chris Page, prevention coordinator for the DNR's aquatic nuisance species program.
"Unsuspecting boaters transport pieces of these plants on boats and trailers and then accidentally introduce them into another body of water."
Hydrilla was discovered in the Little River (Ga.) arm of Strom Thurmond Lake by fisherman Tommy Shaw of Leah, Ga., in 1995 and has since spread to various sections of the 70,000-acre lake.
Hydrilla, water hyacinth and water primrose are among the common problem-makers among non-native plants most responsible for aquatic weed problems in South Carolina.
Lack of natural controls allows these species to develop dense populations that choke native species and obstruct waterways.
The signs also warn boaters about zebra mussels. Although none have been documented in South Carolina waters, the state's lake and river systems are prime targets for this nuisance species.
Zebra mussels attach themselves to solid objects like docks, rocks, boat hulls and water intake pipes.
Their microscopic larvae can be carried in bilge water and cooling water in boat motors. The mussels look like small clams with a yellowish or brownish "D-shaped" shell, usually with dark- and light-colored stripes.
Anyone finding a zebra mussel should store it in rubbing alcohol in a jar and send it and a description of the area in which it was found to the S.C. DNR, P.O. Box 167, Columbia, S.C. 29202, or call 1 (803) 734-9100.