Evaluation of Potential Blue-green Algal Toxins in Lake Champlain (2000), LCBP Technical Report #39

Rosen, B.H., Shambaugh, A., Ferber, L., Watzin, M., Eliopoulos, C., & Stangel, P. (2001). Evaluation of Potential Blue-green Algal Toxins in Lake Champlain (2000) (Technical Report No. 39). Grand Isle, VT: Lake Champlain Basin Program

This report presents a study that investigated the potential of blue-green algae (BGA or cyanobacteria) in Lake Champlain to produce natural toxins and contaminate drinking water after two dogs died in 1999 near juniper island and then again in 2000 near Point au Roche from BGA toxin exposure. This was investigated by sampling water from various sites around Lake Champlain, testing for the presence of BGA and corresponding toxins, and by determining if toxins were present in raw and treated water from five different drinking water treatment facilities during the summer of 2000. Results showed that at least four known toxin producing species of BGA were present in Lake Champlain but only two types of toxins were detected. They also found that while treated drinking water samples all showed less than trace amounts of the toxins, blooms near the vicinities of the intakes showed potential for toxin production at levels of human concern. They concluded that if conditions for BGA growth were more favorable than those experienced in the summer of 2000 that BGA toxin production could pose a contamination risk. They also found that the concentrations of toxins found in zebra mussels in the Rubenstein Ecosystem Science Laboratory boat slip could pose a significant health risk if consumed by humans. They concluded that a widespread bloom of a similar concentration has the potential to impact drinking water and recreational users of the lake. The report makes the recommendation that future efforts should be focused on widespread monitoring for toxin producing BGA blooms. They advise that the monitoring program should be coupled with an action plan to alert water treatment facilities and recreational users in the case of a dangerous bloom and that bioaccumulations of the toxins in the food web should also be further investigated as a potential risk. Note: Data are available in report.