9805585 Jacoby This POWRE project will track the development of toxic cyanobacteria in Lake Sammamish, near Seattle, WA. Rapid residential development is occurring in the watershed of this lake. As forested wetlands are transformed to urban and suburban landscapes, nutrient inputs carried by storm water to the lake have increased and water quality has decreased. One of the symptoms of increased nutrient loading is increased abundance of nuisance species of phytoplankton, particularly bloom-forming cyanobacteria. Some species of cyanobacteria can produce toxins which further degrade water quality. The primary goal of this project is to identify the factors that promote the development of toxic cyanobacterial blooms. To do so, relationships between environmental factors and the development of toxic blooms. Initiation of these blooms will be investigated by monitoring the development and migration of Mycrocystis spp. through the water column coupled with measurements of environmental parameters and resource availability. Interactions between Microcystis and zooplankton will be determined, along with the importance of sediment-to-water column movement of Mycrocystis as an initial source for recruitment. This work will provide valuable information on the relationship between environmental degradation and toxic phytoplankton blooms in freshwater systems. Such information can be used to develop management options to reduce toxicity in these systems.
