Two novel non-destructive biomarkers to assess PAH-induced oxidative stress and porphyrinogenic effects in crabs.

Two novel, non-destructive assays were developed to evaluate contaminant-induced lipid peroxidation (thiobarbituric acid-reacting substances, TBARS, levels) and haem biosynthesis disruption (porphyrin excretion) in decapod crabs. A laboratory experiment was conducted whereby pie-crust crabs (Cancer novaezelandiae) were fed cockles (Austrovenus stutchburyi) collected from a contaminated and reference site and TBARS levels and porphyrin excretion determined using fluorometric analysis in urine samples. Pyrene metabolite levels were also measured in the same urine samples to assess polycyclic aromatic hydrocarbon (PAH) exposure. Contaminant-exposed crabs exhibited elevated urinary TBARS and porphyrin levels and a strong correlation was found between these two assays and the urinary pyrene metabolite concentrations. However, there was large within-treatment variability, which precluded a clear separation between the control and the impacted group. Nevertheless, consistency in the direction of the response shows that the biomarkers reflect pollutant levels and validates the use of these simple techniques from human medicine for environmental assessments.