AN INEXPENSIVE AND EFFICIENT MODULAR WATER-RENEWAL SYSTEM FOR BULK SEDIMENT TOXICITY TESTING

Recently developed test guidance for conducting whole-sediment toxicit y tests with aquatic invertebrates requires exchange of overlying wate r to maintain acceptable water quality. Described here is an accurate and consistent modular water-renewal system (delivering 150 +/- 5 mi r enewal water) and containment chamber for bulk sediment toxicity tests . The system can be customized to meet resting demands by adding multi ple units. Each unit can hold up to 49 300-ml beakers. Construction is simple (<4 h/unit) and inexpensive (<$90/unit). This system has been used successfully in 10-d whole-sediment toxicity tests with Chironomu s tentans and Hyalella azteca.