ABSTRACT
ABSTRACT The quagga mussel (Dreissena rostriformis bugensis) has quickly spread to Lake Mohave and further down the lower Colorado River drainage since its January 2007 discovery in Lake Mead. The microscopic sizes (70 µm or larger) of the veliger life stages make them impossible to see with the unaided eye and dif‘cult to remove from water delivery systems and ‘sh stocking trucks. The purpose of this study is to determine if exposure to different doses of ultraviolet radiation can irreparably damage or kill quagga mussel veligers. The ultraviolet radiation (UVR) exposure doses were 1, 3, 6, and 12 cycles through the SafeGUARD UVR system. After exposure, 50 veligers were sampled and observed at 0, 24, 48, 72, and 96 h. Results indicate that veligers exposed to 12 cycles through the UVR system experienced 100% mortality after 96 h. Results also show asigni‘cant difference in mortality of veligers between one cycle and multiple cycles of UVR exposure (p < 0.05), while there is no statistical difference between cycles 3, 6, and 12 (p > 0.05).
