Connell, D. B. Academy of Natural Sciences, connell@acnatsci.org
Sanders, J. B. Academy of Natural Sciences, jsanders@acnatsci.org
Riedel, G. F. Academy of Natural Sciences, friedel@acnatsci.org

 
THE EFFECTS OF MULTIPLE STRESSORS ON ESTUARINE ECOSYSTEMS: THE RELATIONSHIP BETWEEN NUTRIENT LEVELS AND TRACE METAL UPTAKE IN BIVALVES AND FISH
 
The relationship between nutrient levels and As, Cd, and Cu uptake by bivalves and small fish was examined as a component of the COASTES program currently underway on the Patuxent River (a subestuary of Chesapeake Bay). Modified ecosystems were established in 1000 liter mesocosms for 35 day experiments during three separate seasons in 1997. The ecosystems were exposed to elevated levels of nutrients and trace metals, both separately and in combination. Dissolved and particulate metal and nutrients concentrations were analyzed periodically during the experiments, and As, Cd, and Cu levels in clams (Macoma balthica), oysters (Crassostrea virginica) and Mummichogs (Fundulus heteroclitus) were examined at the end of the experiments. Trace metal uptake varied temporally and among the species. In general, nutrient levels within the mesocosms greatly affected trace metal uptake by bivalves, but had a lesser affect on trace metal levels in fish. For example, nutrients inhibited Cu uptake but stimulated Cd uptake in bivalves. A similar trace metal uptake pattern was also seen in the seston. Thus interactions between nutrients and trace metals play an important role in metal uptake and incorporation at higher trophic levels .
 
Day: Friday, Feb. 5
Time: 04:45 - 05:00pm
Location: Sweeney Center
 
Code: SS28FR0445S