Vanderploeg, H. A.. GLERL/NOAA, vanderploeg@glerl.noaa.gov
Johengen, T. A.. CILER/GLERL/NOAA, johengen@glerl.noaa.gov
Liebig, J. R.. GLERL/NOAA, liebig@glerl.noaa.gov
Nalepa, T. F.. GLERL/NOAA, nalepa@glerl.noaa.gov
Fahnenstiel, G. L.. GLERL/NOAA, fahnenstiel@glerl.noaa.gov

 
FROM INDIVIDUAL BEHAVIOR TO ECOSYTEM RESPONSE: INTERACTIONS AMONG ZEBRA MUSSELS, THE ALGAL COMMUNITY, AND NUTRIENT CYCLING
 
Nutrient concentrations and zebra mussel filtering affected algal concentration and community composition, including Microcystis abundance in Saginaw Bay (Lake Huron) and Lake Erie. In turn, the quality of the algal community affected filtering rate, N and P excretion, and condition of the mussels. Important qualities of the algae included species composition and N:P ratios. Microcystis dominance led to both lowered feeding and nutrient excretion, especially P. In Saginaw Bay, where seston N:P ratios were much higher than the Redfield ratio: filtering rates were low, condition of the mussels was poor, P excretion was low, and the N:P ratio excreted was lower than that of the seston. In Lake Erie, where seston N:P ratios were lower than the Redfield ratio: filtering rates were high, condition of the mussels was good, P excretion was high, and the N:P ratio excreted was near the Redfield ratio. Thus, zebra mussel nutrient excretion in the P-limited environment may have led to further P limitation. The occurrence of Microcystis in these two systems of different nutrient availability points to the importance of selective filtering as the major mechanism of algal community change.
 
Day: Wednesday, Feb. 3
Time: 02:45 - 03:00pm
Location: Eldorado Hotel
 
Code: SS18WE0245E