The Vermont Agency of Natural Resources, in cooperation with the St. Albans Area Watershed Association, conducted a study of the effectiveness of SolarBee (TM) water circulators in reducing algae blooms at the northern end of St. Albans Bay, Lake Champlain during 2007. The study found no evidence that the SolarBees reduced algal concentrations, improved water clarity, or inhibited blue-green algae in St. Albans Bay. The treatment goal of producing an approximately 100-acre zone of clear, low-algae water at the northern end of St. Albans Bay was not achieved by the SolarBee deployment. A report on the study is available at: VANR Solar Bee Report Final.
St. Albans Bay in Lake Champlain (Vermont) has a long history of excessive phosphorus levels and summer algae blooms dominated by cyanobacteria (blue-green algae). Efforts to reduce point and nonpoint sources of phosphorus have not succeeded in controlling the algae blooms. Three SolarBee® water circulator devices were operated in St. Albans Bay during May-August 2007 with the goal of reducing algae levels and improving water clarity over a total area of approximately 100 acres at the northern end of the bay. The effectiveness of the SolarBees in achieving this goal was tested by lake monitoring during the deployment period. The monitoring program used a spatial control design in which water quality conditions within the presumed 35-acre treatment zone around each SolarBee unit were compared with conditions at greater distances from the devices. Mapping of the spatial distribution of chlorophyll-a and Secchi disk transparency data showed no consistent relationship with the treatment zones around the three SolarBee units, and no evidence of generally depressed algal growth or clear water within the treatment zones. A statistical analysis of the spatial data found that there were no significant reductions in mean chlorophyll-a concentrations or increases in Secchi disk transparency within the treatment zones when compared with levels immediately outside the treatment zones. The SolarBees did not produce a more uniform vertical distribution of chlorophyll-a in the water column than what was seen outside the treatment zones. The devices had no discernable effect in reducing the relative dominance of cyanobacteria within the phytoplankton community inside the treatment zones, based on microscopic examination of water samples. In conclusion, there was no evidence that the SolarBees in St. Albans Bay reduced algal concentrations, improved water clarity, or inhibited blue-green algae in the bay. The treatment goal of producing an approximately 100-acre zone of clear, low-algae water at the northern end of St. Albans Bay was not achieved by the SolarBee deployment.