The acute toxicity of sediment samples from Santos Estuary was evaluated by using sediment toxicity tests with the burrowing amphipod Tiburonella viscana. Survival of amphipods acclimated for 2 and 15 days was also analyzed. The sensitivity of this species was evaluated by 48h-exposure tests using potassium dichromate (K2Cr2O7) as a reference substance. The sediment samples from Gonzaga Beach, Prainha and Paranapuã Beach were not toxic to T. viscana, whereas the samples collected at Santos Channel and São Vicente Bay were toxic. The acclimation period did not affect survival significantly, in spite of the higher mortality within the 15-day acclimated group. The estimated 48-h LC50 to K2Cr2O7 was 6.029 mg/L (3.27-11.12). Toxicity tests using T. viscana were useful in assessing the quality of sediments of Santos Estuary. Moreover, this amphipod was considered as sensitive as other amphipods used in toxicity tests elsewhere. Thus, toxicity tests using Tiburonella viscana should be recommended as part of future monitoring programs.
Amphipoda; Tiburonella viscana; toxicity test; sediment
