Laserfiche WebLink
EXECUTIVE SUMMARY <br />introduced in North America in 1986, the exotic zebra mussel, Dreiaena <br />polymorpha, has quickly spread in the Great Lakes region and Eastern ilnited <br />States. This aquatic nuisance species is expanding its western range, and is a <br />threat to Western aquatic ecosystems and water management facilities. Prevention <br />programs in the East have not developed quickly enough to effectively reduce the <br />spread of this species, and no programs have been developed to reduce or limit its <br />invasion into the West. <br />Unlike native North American <br />freshwater mussels, the zebra mussel <br />has a free floating, planktonic larva that <br />has aided in its rapid spread by water <br />currents into downstream areas. These <br />planktonic larvae can not move against <br />an upstream gradient, and this will <br />limit their ability to spread further <br />west. In addition, spread of the zebra <br />mussel in the Western United States <br />to, and across, the North American <br />Continental Divide will require its <br />transport across long distances in an <br />grid climate. Mussels attached to boats <br />and other movable equipment will be <br />subjected to desiccation over a long <br />time period. Thus, natural conditions <br />will assist in limiting further western <br />spread and presumably provide the first <br />opportunity to slow or halt the <br />continuing spread of this species across <br />the continent. <br />In addition to constraints placed on <br />zebra mussel invasion by climate and <br />geography, it may be possible to use <br />