Impacts of Zebra Mussel Veliger Control Treatments on the Survival of Water-Hardened Landlocked Fall Chinook Salmon Eggs

Abstract

Several treatment options have been developed to minimize the spread of zebra mussel Dreissena polymorpha veligers (larvae) during fish transportation. However, the effect of these treatments on the survival of newly-fertilized salmonid eggs has not been evaluated. This study examined the survival of water-hardened landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs after one of four different treatments: 1) Control (no chemicals), 2) 100 mg/L formalin for two hours, 3) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for two hours, and 4) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for three hours. The 100 mg/L formalin treatment produced complete egg mortality. Survival to hatch was not significantly different among the other three treatments. Based on these results, the use of 750 mg/L potassium chloride for one hour followed by 20 mg/L formalin for three hours is recommended when moving Chinook salmon eggs from waters potentially infested with zebra mussels to hatcheries for incubation.

Review of Methods to Repair and Maintain Lithophilic Fish Spawning Habitat

“…However, mussel prevention and removal techniques are being field-tested, and some targeted removal strategies may be employed to maintain rocky spawning habitats. Aquaculture facilities can also prevent the spread of veligers (i.e., larval dreissenid mussels) by treating water containing fish eggs [164,165] and juvenile fish [166] during transport to other water bodies. In newly colonized areas, manual removal of small mussel beds by divers is labor intensive but may be possible to prevent further spread, such as in Lake George, New York, USA (not shown, 43.4262 • N, 73.7123 • W) [167].…”