Biochemical effects of water-soluble fraction of oil (wsf) on the amphipod Hyalella curvispina

DEL BRÍO J; MONTAGNA M; VENTURINO A

Santos

Congreso; 12th Biennial Meeting Society of Environmental Toxicology and Chemistry (SETAC) Latin America; 2017

SETAC LA

The Province of Neuquén is located in the northern region of the Argentinean Patagonia, where the exploitation of energy resources is the most relevant economic activity. The oil and gas fields from this area produce 48% and 23% of Argentina?s total production; respectively. Therefore, this zone is exposed to oil pollution derived from drilling, production and transport of crude oil. During the last years, studies from the area have demonstrated the presence of hydrocarbons in some water courses and sediments. In addition, low concentrations of polyaromatic hydrocarbons (PAHs) such as naphthalene and pyrene were detected. Oil contamination causes a serious problem to aquatic life. Previous investigations of crude oil contamination have revealed that their toxicity is mainly due to the water-soluble fraction (WSF), rather than to the dispersed droplets of the fraction. Thus, the aim of this work was to evaluate the time dependent effects of a sublethal dilution of WSF on the activity of detoxifying enzymes in adults of H. curvispina. Crude oil obtained from Chachahuen field, North Patagonia region and supplied by YPF Company was used to prepare the WSF. Amphipods were sampled from Los Barreales lake (LB) and Durán stream (DS), nearby the urban area of Neuquén City where the presence of hydrocarbons was previously determined. The enzymatic activity of glutathione-S-transferase (GST) and catalase (CAT) and reduced glutathione content (GSH), were assessed in both control and exposed (1:1600 dilution for 6, 24 and 48 hours) amphipods. Both LB and DS showed a significant increase (more than 100%) on GSH content after 6 hours of exposure compared to control groups. GST activity was significantly decreased after 24 and 48 hours of exposure in LB amphipods, while the ones from DS showed an increase on GST activity after 24 hours of exposure compared to control group. There was an increase of about 30% of CAT activity in LB organisms after 24 hours of exposure, while those from DS decreased CAT activity along whole exposure. In conclusion, control adults from the DS exhibited lower GSH content and GST activity than control adults from the LB, evidencing a differential response between the two populations in relation to the quality of the sampling site. Short-term exposure to WSF also produce oxidative stress in both populations in view of the changes observed in the components of antioxidant system.