PARENT SESSION

3D - Exposure and effects of environmental contaminants in marine organisms
Hall 7
8:30 AM - 12:30 PM, Tuesday, 29 April 2003
Chair: Scholz, N.¹, ¹
Co-chair: Karbe, L.², ²

(TU7/6) Evaluation of ammonium chloride as toxic standard in a water-phase test design with Corophium volutator.

Noack, Udo¹, Kraetzig, Gwendolin¹, ¹ DR. U. NOACK-LABORATORIUM FÜR ANGEWANDTE BIOLOGIE, Sarstedt, Niedersachsen, Germany

ABSTRACT- We will introduce a modified marine bioassay that is suitable for acute sea water testing and recommends ammonium chloride as toxic standard. The marine/estuarine amphipod Corophium volutator lives in high densities in fine muddy sediments and tolerates strong variations of temperature and salinity levels. It plays an important role in the food chain and is more and more used in marine sediment testing (A Marine Bioassay Test Set to Assess Marine Water and Sediment Quality - Its Need, the Approach and First Results, PETERS et al., Ecotoxicol. 11, 37-383, 2002). Toxicity of ammonium chloride on C. volutator was examined at different temperatures (15, 16, 17 ^oC), salinities (10, 20, 30 S), origin of the animals (breeding or natural poulation) and test durations (24 h - 240 h). Additionally we compared the sensitivity of C. volutator with different life stages (expressed on mean body length) on ammonium. Exposure tests were performed in the aqueous phase to set up the EC₅₀ for ammonium on C. volutator dependent on exposure time (Marine Biotest: Comparative Investigations on Acute Toxicity of Ammonium Chloride to Corophium volutator, NOACK et al., Fres. Env. Bulletin, 2002, in press). Endpoint of the determination was mortality/immobility. Studies were taken place in artificial seawater (SIGMA Sea Salts) and in selected tests with original water from the Baltic Sea. Toxicity of ammonium showed no statistically significant differences at different salinities, temperatures, keeping durations and life stages of C. volutator. Ammonium chloride has been proven as reference substance for a positive control in chemical testing procedures. A recommendation for using will be presented.

Key words: ammonium chloride, Corophium volutator, toxic standard, water-phase test design