MP8 Metals in the Environment: Dietary concerns in Aquatic Systems
Monday, 14 November 2005: 8:00 AM - 5:30 PM in Exhibit Hall
(BIE-1117-814179) Toxicity of silver, zinc, copper, and nickel to Acartia tonsa, exposed via a phytoplankton diet.
Bielmyer, G.1, Grosell, M.1, Brix, K.1, 2, 1 University of Miami, Miami, Fl., USA2 EcoTox, Key Biscayne, Fl., USA
ABSTRACT- Toxicity tests were conducted with the marine copepod, Acartia tonsa, to assess the importance of dietary metal exposure on survival and reproduction. The diatom, Thalassiosira pseudonana was cultured with bioavailable forms of Ag, Zn, Cu, or Ni during log phase (6 d) and then used as diets for adult A. tonsa over a 7-d exposure period. Survival and reproduction were measured throughout the exposure period. For all metals, reproduction was the most sensitive endpoint and was effected at relatively low levels of exposure. The estimated 20 % effect concentrations (EC20s) were 0.64, 0.3, 1.2, and 2.4 
g/L for Ag, Zn, Cu, and Ni, respectively in the algal media. The corresponding metal concentrations in the algae (EC20s) were 5.44, 0.55, 22.3, and 15.3 g/g for Ag, Zn, Cu, and Ni, respectively. None of the applied metal concentrations influenced algal growth. The results of this study may have implications for water quality criteria for these metals considering that the estimated EC20s fall below the current criteria of 3, 86, 3, and 8.3 g/L for Ag, Zn, Cu, and Ni, respectively.
Key words: Marine, Metal, Toxicity, Phytoplankton