Role of Dreissenid Mussels in Transforming Nutrient Loads into HABs

Current empirical models attempt to forecast the spatial extent and magnitude of cyanobacterial harmful algal blooms (cyanoHABs) in western Lake Erie from phosphorus loading during spring months. These models work well in some years but not in others. The connections between spring loading and summer bloom extent and location are not well defined or understood. Nor is the connection between nutrient loading and toxicity of the bloom well defined. A target reduction of loading of 40% has been chosen to ameliorate proliferation of HABs in Lake Erie. Will a 40% reduction in P loading achieve the goal and how important is timing of loads to managing the problem? Management of amount and timing of nutrient reduction to achieve the desired goal cannot be specified until a mechanistic understanding of the reasons for the temporal offset to loading and other factors responsible for bloom initiation, maintenance, and toxicity are better understood. A major factor that must be considered in understanding initiation, extent, location, and toxicity of HABs blooms is the role that dreissenid mussels are playing in western Lake Erie. This project will use a combination of field surveys to assess dreissenid mussel abundance, seasonal condition and growth, and lab experiments to measure mussel feeding and nutrient excretion rates using Lake Erie seston and laboratory cultures to determine the impact of mussels in transforming nutrient loads into harmful algal blooms.

GLRI Funding
FY2017: $491,676