408 The UMAP Journal 22. 4(2001) intake system to prevent the unintentional introduction of new species. The improved sighting, reporting, and education under this plan will help the pub lic and commercial sectors prevent the spread of zebra mussels Reactive Control Strategies Acute Zebra Mussel Infestation In cases of acute or localized infestations, ap- plying the least expensive method of preventing infrastructure damage is to employ a foul release coating in concert with mechanical cleanings and mechanical filtration. Coating pipes and surfaces in contact with the water with antifouling polymers, such as silicones and fluorochemicals, creates a slippery surface that makes it difficult for zebra mussels to attach [Magee et al. 1996]. These reagents are effective for 2-5 years [Boelman et al. 1997 Analternative and equally successful method of infrastructure protection is the application of zinc thermal spray (zts)on metal surfaces. In addition to preventing corrosion, ZTS is the most durable and long-lasting zebra mussel repellent. The slow dissolution of heavy metal ions from ZTS is toxic to zebra mussels. In addition, the US Army Corps of Engineers Zebra Mussel Control Handbook suggests that low release of heavy metals and a large dilution factor produce minimal secondary effects on nontarget species. However, before implementing this strategy, it is critical that the environmental effects studied and the implementation meet federal standards. Mechanical cleaning is a labor-intensive method of removing zebra mussel from infrastructure. The drawback to simply brushing and scraping zebra mussels off surfaces is that the scrubbings need to be repeated regularly The removed zebra mussels also have to be transported and disposed of in landfills The final strategy for dealing with acute zebra mussel infestation is in- stalling mechanical filtration systems. Water screen filters and strainers can be placed on water intakes. A mesh size of 25-40 mm is able to stop the inflow of veligers and translocation of larger zebra mussels. However, this system requires continuous maintenance Global Zebra Mussel Infestation Severe and large-area infestation and pop- ulation expansion need to be treated with aggressive methods, since it is more beneficial to address the widespread infestation problem rather than fight specific site-related mussel-density problems. Since these methods re- quire widespread application, the expense associated with implementation is higher than the strategies for dealing with acute infestation. There is also a potential for harming native organisms and commercial industries. How ever,after intense scrutiny, the following methods are the most effective ways to control and potentially eradicate severe zebra mussel infestations Thermal treatment. The discharge of heated water is a cost-effective and efficient method for controlling and eradicating the macrofouling ze bra mussel. Since zebra mussels are able to acclimate to temperature408 The UMAP Journal 22.4 (2001) intake system to prevent the unintentional introduction of new species. The improved sighting, reporting, and education under this plan will help the pub￾lic and commercial sectors prevent the spread of zebra mussels. Reactive Control Strategies Acute Zebra Mussel Infestation In cases of acute or localized infestations, ap￾plying the least expensive method of preventing infrastructure damage is to employ a foul release coating in concert with mechanical cleanings and mechanical filtration. Coating pipes and surfaces in contact with the water with antifouling polymers, such as silicones and fluorochemicals, creates a slippery surface that makes it difficult for zebra mussels to attach [Magee et al. 1996]. These reagents are effective for 2–5 years [Boelman et al. 1997]. An alternative and equally successful method of infrastructure protection is the application of zinc thermal spray (ZTS) on metal surfaces. In addition to preventing corrosion, ZTS is the most durable and long-lasting zebra mussel repellent. The slow dissolution of heavy metal ions from ZTS is toxic to zebra mussels. In addition, the US Army Corps of Engineers Zebra Mussel Control Handbook suggests that low release of heavy metals and a large dilution factor produce minimal secondary effects on nontarget species. However, before implementing this strategy, it is critical that the environmental effects studied and the implementation meet federal standards. Mechanical cleaning is a labor-intensive method of removing zebra mussel from infrastructure. The drawback to simply brushing and scraping zebra mussels off surfaces is that the scrubbings need to be repeated regularly. The removed zebra mussels also have to be transported and disposed of in landfills. The final strategy for dealing with acute zebra mussel infestation is in￾stalling mechanical filtration systems. Water screen filters and strainers can be placed on water intakes. A mesh size of 25–40 mm is able to stop the inflow of veligers and translocation of larger zebra mussels. However, this system requires continuous maintenance. Global Zebra Mussel Infestation Severe and large-area infestation and pop￾ulation expansion need to be treated with aggressive methods, since it is more beneficial to address the widespread infestation problem rather than fight specific site-related mussel-density problems. Since these methods re￾quire widespread application, the expense associated with implementation is higher than the strategies for dealing with acute infestation. There is also a potential for harming native organisms and commercial industries. How￾ever, after intense scrutiny, the following methods are the most effective ways to control and potentially eradicate severe zebra mussel infestations. Thermal treatment. The discharge of heated water is a cost-effective and efficient method for controlling and eradicating the macrofouling ze￾bra mussel. Since zebra mussels are able to acclimate to temperature