Hyalella curvispina (AMPHIPODA) AS A TEST ORGANISM IN LABORATORY TOXICITY TESTING OF ENVIRONMENTAL SAMPLES

An intercalibration exercise using blind-liquid samples containing Cr+6 and Zn+2 as well as environmental sediment samples was carried out between two laboratories using H. curvispina as test organism. For liquid samples, LC50 96-h values were in the same order of magnitude for both metals in each laboratory. The tested sediments in each laboratory included a control sediment, two heavily contaminated sediments (Riachuelo and Oeste Canal) and a moderately contaminated sediment (Lujan River). In the whole-sediment tests, an acceptable level of survival for the controls was obtained by both laboratories. Contaminated sediment samples exhibited high toxicity in both laboratories, while moderately contaminated sediment samples did not exhibit lethality, being survival >80%; nevertheless, growth was significantly lower compared with negative controls in test organisms exposed to sediments of this stream. This study provides relevant information for the validation of H. curvispina as a test organism in sediment monitoring studies at regional level.