In the global war against alien mussels, a significant arsenal of manual, chemical, and biological weapons has been used against zebra and quagga mussels. Chlorine has been effective, but the amount of chlorine needed to fight both the zebra and quagga mussels would be lethal to most other organisms—including us! Cutting off the oxygen supply, heating the water, drying up areas of the lake, using radiation and a host of poisons, sonic vibrations, and even zapping the water with electrical charges have all been proposed—and some of these methods have been tried. The least harmful, but still effective, method is to physically scrape the mussels away.