Evaluation of toxicity for mysidopsis juniae species in cases of oil spill in the brazilian potiguar basin

This study aimed to assess the toxicity of the water soluble fraction (WSF) and correlate the effects of three oils and their compositions, through the bioassay with the Mysidopsis juniae, the analysis of n-alkanes and specific gravity. The PET01 and PET02 oils were classified as light oils ºAPI 39.8 and 32.8 and paraphynics with more abundant n-alkane ranges from n-C10 to n-C16, and n-C9 to n-C32. The PET03 oil was classified as heavy (°API 19.7), with more abundant hydrocarbons in the range of n-C29 and n-C33. It was also possible to evaluate the concentrations of metals in petroleum, Ba (3.41-4.45 mg/kg), Fe (5.42-9.01 mg/kg), Zn (0.18-0.53 mg/kg) and Ni (1.77-3.55 mg/kg) were present in the composition and may have harmful effect even at low concentrations. The acute toxicity of WSF from the oils varied by oil type, with LC50 11.4-27.6 of % WSF. Spill simulations indicated that short-term exposures in areas spilled with these oils are less toxic, but with increasing oil and seawater contact time (>1 h), the toxicity and solubility of total BTEX increases. The toxicity of the samples was directly related to the composition of the oils and categorized by the ecotoxicological risk to the environment from PET01 > PET02 > PET03. These results provide reliable data for ecotoxicological risk assessments in cases of oil spillage in marine environments.