TP3 Metals in the Environment: Dietary Concerns in Aquatic Systems
254 Portland Ballroom
1:20 PM - 4:40 PM, Tuesday
() Effects arising from trophic transfer of silver and copper in a phytoplankton-zooplankton food chain.
Bielmyer, G1, 2, Grosell, M1, Brix, K2, 1 RSMAS, University of Miami, Miami, Fl, USA2 ECOTOX, Key Biscayne, Fl, USA
ABSTRACT- Dietary metal exposure has been shown to cause sub-lethal effects in aquatic organisms. Unlike waterborne metal exposure, however, the mechanism of dietary metal toxicity is not well characterized. In addition, recent studies indicate that dietary metals may be more toxic than previously thought. Some controversy exists over this issue, which may in part be attributed to the composition of the diets. Biologically incorporated metals may be more bioavailable than metal-enhanced prepared diets. Toxicity tests are being conducted with the zooplankton, Acartia tonsa, to assess the importance of the dietary exposure route. The copepod, A. tonsa are maintained in culture on a mixture of marine algal diets consisting of Thalassiosira pseudonana, Isochrysis galbana, skeletonema costatum Tetraselmis sueccica and Rhodomonas salina. For metal toxicity studies, T. pseudonana was grown with either Ag or Cu during log phase and then used as diets for A. tonsa over 8-d. Results to date have shown reduced survival in A. tonsa fed algae grown in media containing concentrations near the water quality criteria. Survival and reproduction, determined by egg production and hatching success are being measured throughout the exposure period in ongoing and future experiments.
Key words: metals, dietary, phytoplankton, zooplankton