ABSTRACT
ABSTRACT The transfer of ‘sh from mussel-positive waters is a potential vector for moving quagga mussel Dreissena rostriformis bugensis and zebra mussel Dreissena polymorpha veligers to new water bodies. Amultitude of chemicals have been published as effective molluscicides, but most are used over an extended period of time and are highly toxic to ‘sh. The goal of our study was to develop atimelimitedtreatment that will ensure 100% mortality of D. bugensis veligers while not negatively impacting ‘sh exposed simultaneously to the treatment. The ef‘cacy of 18 chemicals as molluscicides was tested at multiple concentrations and treatment times on D. bugensis veligers and native ‘sh species under water conditions of the southwestern United States. The acute toxicity data were highly variable, but one consistentresult was that D. bugensis veligers exhibited greater tolerance to the chemicals than native ‘sh species. Six chemicals produced 100% veliger mortality, but ‘ve (Peraclean® 15, magnesium chloride, menthol, propylene phenoxytol, and aclove oil/menthol mix) were at concentrations that cannot be toleratedby native ‘sh. The sixth chemical, potassium pyrophosphate, did not appear to negatively impact the ‘sh, but further testing is required because of the formation of aprecipitate in the dilution water. Future research on the survivability and viability of veligers exposed to sublethal concentrations of these chemicals would provide greater insight into their potential use as molluscicides.
