Abstract

LACMA, Julio; IANNACONE, José  and  VERA, Giovanna. Chromium toxicity in a sediment using donax obesulus Reeve 1854 (pelecypoda: donacidae). Ecol. apl. [online]. 2007, vol.6, n.1-2, pp.93-99. ISSN 1726-2216.

Chromium toxicity assessment of marine sediments in Peru is a topic of increasing interest. Mean lethal concentration of chromium (Cr⁺⁶) using the marine bivalve Donax obesulus Reeve 1854 (Pelecypoda: Donacidae) at 24 h, 48 h and 96 h of exposure was assessed, as well as its burying ability in a chromium (Cr⁺⁶) sediment. For D. obesulus acclimatization and rearing the marine microalga Dunaliella tertiolecta Butcher was employed. The assay was performed with 22.4 mm ± 1.5 mm D. obesulus adults. Mean lethal concentration (LC₅₀) in chromium Cr⁺⁶ D. obesulus marine sediment was 410.4 mg·kg^-1, 156.1 mg·kg^-1 and 61.12 mg·kg^-1 at 24 h, 48 h and 96 h of exposure, respectively. A guideline value proposed by Long et al. (1995) for chromium in an aquatic sediment is 370 mg·kg^-1. The results obtained in terms of LC₅₀ at 48 h and 96 h for D. obesulus, exposed to chromium, were 57.8% and 83.5%, lower than the guideline value, respectively. Chromium presented a notorious sublethal effect on D. obesulus burying ability at 48 h of exposure. The protocol using D. obesulus has advantages in terms of sensibility, easy use, simplicity of reading, low cost and ecological realism.

Keywords : bioassay; ecotoxicology; pelecypod; chromium; Donax obesulus; sediment.

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