Baseline levels of biomarkers of oxidative damage in Odontesthes nigricans (Pisces, Atherinopsidae) from two coastal areas of the Beagle Channel, Argentina

Abstract

We assessed several biomarkers of oxidative damage on silversides Odontesthes nigricans from Varela and Golondrina bays, located on the North shore of the Beagle Channel (Tierra del Fuego, Argentina) and we tried to relate those responses to environmental data. Varela bay is visited mostly by local fi shermen and tourism during the spring-summer season; on the other hand Golondrina bay is a low urban impacted area, despite the population?s growth around it. We employed the condition factor as general biomarker of fi sh health and quantifi ed biomarkers of oxidative damage in gills and liver. Fishes from Golondrina bay showed a better condition as compared to those from Varela bay. The activity of enzymatic antioxidants and the content of non-enzymatic antioxidants were lower in gills than in the liver, independently of the sampling site. No signifi cant differences were found between sites in the gills. However, an increase in catalase and superoxide dismutase activities and a decrease in GSH/GSSG ratio were observed in the liver of fi shes from Varela bay, possibly being due to higher levels of environmental natural stresses, mainly metals in sediments. This study indicates an organ-dependent response and establishes different baseline levels of biochemical parameters for each bay that could be considered as values of normal homeostasis for wild silversides.