Zebra mussels, first found in North American waters in 1988 at Lake St. Clair, Michigan, have since found their way into many midwestern, eastern, and southern streams and lakes. They are macrofoulers that quickly colonize new areas on many different types of natural and artificial substrates. The potential exists for these organisms to infest most freshwater lakes and rivers in the United States. Once established, the zebra mussel can achieves very high densities, with adult mussels producing byssal threads to attach to any available hard substrate. The zebra mussel is a serious threat to public facilities, and the extent of future infestation is still unknown.
An effective, cost efficient zebra mussel control program must consist of a thorough monitoring plan and implementation of applicable control methods relevant to the operating situation at hand. Monitoring is a key component of preventative maintenance and control because it provides information on the presence of zebra mussels, their abundance in the water system, and the effectiveness of treatment programs.
There are numerous zebra mussel control methods that can be separated into preventive and reactive measures. Preventive control strategies reduce the possibility of infestation occurrence. These methods include toxic construction materials, antifouling coatings, thermal treatment, and mechanical filtration. Reactive control strategies are utilized after an infestation has been detected. Reactive methods include replacing fouled component, mechanical cleaning, high pressure water jetting, carbon dioxide pellet blasting, and freezing or desiccation.
As newer environmental restrictions are placed on their use, more environmentally benign techniques need to be investigated to determine their potential applicability at public facilities. Prospective treatments and retrofits such as component enlargement, self-cleaning nozzles, acoustics, electric fields, and UV light have demonstrated possible applications. Further testing and development is required in these fields to ensure zebra mussel control effectiveness and applicability to floating plant.
Information sharing should continue through both formal and informal networks, such as the Zebra Mussel Information Clearinghouse and the ZMRP. New research areas should be identified and funded; however, full advantage should be taken of ongoing work in this country and elsewhere.