PT13 Aquatic Ecotoxicology I
Exhibit Hall
8:00 AM - Tuesday
(PT204) The Effect of Na+, K+, and Cl- Ions on Brazilian Test Species used in Drilling Fluid Toxicity Tests.
Rabke, S1, Luiz, V2, Reynier, M2, Kraus, L2, Maurat, M2, França, J1, 1 MI SWACO, Houston, TX, US2 Labtox - Laboratório de Análise Ambiental Ltda., Rio de Janeiro, Brazil
ABSTRACT- Toxicity tests are commonly used worldwide to regulate the offshore discharges of drilling fluids. Though common, there are various approaches in the use of information gathered from these testing schemes as well as mutual tests and test species. In Brazil, although the lack of laws defining specific limits for LC50 for the drilling fluids toxicity, the federal environmental protection agency (IBAMA) requires toxicity data in order to issue permits for offshore drilling operations. Included in the various species used in Brazil for toxicity testing are the mysid Mysidopsis juniae and the sea-urchin Lytechinus variegatus. It has been shown that the mysid species used in the Gulf of Mexico is sensitive to increased levels of potassium ions. Tests of drilling fluids with various levels of Na+ and K+ ions have shown that the Brazilian species are also sensitive to increased levels of these ions. This study provides data on controlled experiments of the effects of K+, Na+, and Cl- ions to M. juniae and the sea-urchin L. variegatus.
Key words: ions, toxicity , Mysidopsis juniae, Lytechinus variegatus