The Effect of UV-C on Larval Survival of the Quagga Mussel

First introduced to the Great Lakes, quagga mussels (Dreissena rostriformis bugensis) have thrived and spread throughout North America. Since their Midwestern introduction, quagga mussels have begun to overtake the equally invasive zebra mussel and have since spread west of the Rocky Mountains. The invasion and rapid spread of mussels has caused significant economic and management challenges to hydropower and fisheries. Current strategies for mitigating the growth and spread of quagga mussels include physical and chemical means of removing adults, but they negate other stages within the life history and are oftentimes costly and labor intensive. In the present study, germicidal ultraviolet light (UV-C) is used to target the free swimming larvae and it’s effectiveness in causing mortality was evaluated at four doses: 0, 13.1, 26.2, and 79.6 mJ/cm². This, to our knowledge is the first dose response study on quagga mussels exposed to UV radiation and it was demonstrated that with a low dose of 26.2 mJ/cm², survival of pre-settlement stage larvae could be reduced by 50% after 4 days post-exposure.