SS4.03 Factors Controlling the Bioavailability and Bioaccumulation of Inorganic and Organic Chemicals into Aquatic Food Chains
Date: Friday, June 14, 2002
Time: 8:45:00 AM
Location: Carson B
 
FoltCL, Dartmouth, Hanover, USA, Carol.Folt@Dartmouth.edu
Chen, C, Y, Dartmouth, Hanover, USA, Celia.Chen@Dartmouth.edu
 
COMPARING THE POTENTIAL FOR ZOOPLANTKON TAXA TO TRANSFER METALS FROM WATER TO FISH
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The public is becoming increasingly concerned about their exposure to toxins such as mercury via consumption of fish. However, factors determining the movement of metals through aquatic food webs are still under investigation in a search to derive strong predictive models for relating metals levels in the water to metal levels in fish. This study compares three common zooplankton taxa (cladocerans, calanoid and cyclopoid copepods) for their potential to transfer metals (e.g. Hg, As, Cd, Zn) to top predators. Data will be presented comparing (1) metal levels in each group from 14 survey lakes and (2) from Upper Mystic Lake, MA taken three times during a single growing season. In all cases, cladocerans, which are an important food for planktivorous fish, carried greater burdens of some metals (Hg, As) than copepods from the same lakes. Taxonomic differences persisted seasonally, but the magnitude of the differences varied considerably. In contrast, other metals (Cd, Zn) were less consistent with respect to taxonomic differences. Implications for modeling trophic transfer of metal in lakes of various types will be discussed.