Oppert, C. J. University of Maryland REU, email@example.com
THE EFFECTS OF INCREASED NUTRIENTS, TRACE METALS, AND DIATOM FOOD ON EGG PRODUCTION RATES OF THE ESTUARINE COPEPOD, ACARTIA TONSA
The effects of food quality on the egg production rates of Acartia tonsa were examined in two studies. A. tonsa is the dominant calanoid during the most productive months in Chesapeake Bay. In the first study, egg production of A. tonsa females from 1 m3 and 10 m3 mesocosms was measured. Females from mesocosms with elevated levels of nutrients and trace metals had lower egg production rates than females from control mesocosms.
Preliminary data suggest that egg production rates were not with phytoplankton biomass. Thalassiosira weissflogii were offered as food. R. fragilissima is a bloom alga in Chesapeake Bay, and shows variable responses to elevated concentrations of trace metals. Egg production decreased significantly in the R. fragilissima treatments compared to the T. weissflogii treatment, and was not significantly different from that of starved copepods. In combinations of the two diatoms, egg production did not differ from treatments where T. weissflogii was offered alone. These studies provide evidence that information on changes in species composition, rather than on changes in prey biomass alone, is critical to the understanding of the impacts of anthropogenic stressors on secondary production in estuarine systems.
Day: Wednesday, Feb. 3
Location: Sweeney Center