Use of fish embryo biomarkers for the evaluation of mazut toxicity in marine environment

Abstract

The risk of oil contamination, either through produced water discharges, accidents, or non-point-sources, has increased, and it is attributed with the negative impact on the Black Sea ecosystem, and especially in coastal waters. Coastal marine waters are known as the areas of fish and invertebrates spawning sites, including commercial species, which early developmental stages are highly sensitive to crude oil and its derivates. The aim of the present study was to investigate the effects of mazut at concentrations of 0.00001, 0.0001, 0.001, 0.01, 0.1, and 1 ml l−1 on the biomarker response in the developmental embryos (stages IV and V) of tubenose goby <em>Proterorhinus marmoratus.</em> We used the biomarkers of antioxidant enzyme activities, namely superoxide dismutase (SOD), catalase (CAT), peroxidase (PER) and glutathione reductase (GR). The non-uniform response on mazut impact at tested concentrations on fish embryos was shown. The best biomarker was peroxidase activity, which was highly sensitive to oil pollution and reflected the response of the organism on stressful environment. The imbalance between tested antioxidant enzyme activities was clearer at low and high levels of mazut, and it was less in the case of medium values. The obtained results can be applied for the development of oil toxicity tests for monitoring management and for perspectives of conservation ecology.