| Abstract/Description or Keywords |
Mackie and Claudi (2010) describe the devastation of native unionids, especially species at risk, by dreissenids in numerous watersheds in North America. The rapid dispersal of dreissenids beyond the 100th Meridian is causing concern of its invasion into BC watersheds, especially those that support populations of mussel species at risk, such as the Rocky Mountain Ridged Mussel (RMRM), Gonidea angulata, which is presently listed by COSEWIC as special concern. Since the RMRM is common throughout most of Okanagan Lake, there is concern that if the water quality of the lake will support massive infestations of zebra and/or quagga mussels, the dreissenids may kill existing populations of the RMRM. Mackie and Claudi (2010) describe methods for predicting the level of infestation by dreissenids based on water quality. The most common parameters used (and listed in order of their predictive value from most reliable to less reliable) are: 1, calcium content; 2, alkalinity; 3, pH; 4, total hardness; 5, nutrient (total phosphorous, total nitrogen) levels; 6, chlorophyll a levels; 7, Secchi depth; 8, dissolved oxygen content; 9, conductivity (and/or salinity, total dissolved solids); 10, mean annual temperature. Although mean annual values of each of the parameters can be used, temporal (e.g. seasonal) and spatial (e.g. depth, horizontal) variations lend more certainty to the predictions of mussel survival and potential densities. However, means and ranges of these water quality parameters can be very useful for a rapid assessment of infestation potential. water quality, invasive species |
