Phase I and II biotransformation and antioxidant enzymes in the coral Siderastrea siderea act as biomarkers for reproductive condition and habitat quality

Abstract

In this study we examined the behaviour of biomarkers in corals combining the reproductive status of colonies and reef sites with different levels of contamination. The content of P450 and P420 and the activities of NADPH c reductase, glutathione S-transferase (GST), catalase (CAT) and superoxide dimutase (SOD) were measured in the coral Siderastrea siderea at two marine parks. Parque Nacional Morrocoy (PNM) encompasses a continental marine ecosystem largely influenced by anthropogenic impacts. In contrast, Parque Nacional Archipielago Los Roques (PNALR) is 160 km offshore and relatively less impacted. As these enzymes are also affected by reproduction, samples were taken in both parks during the reproductive and non-reproductive seasons. In both parks, NADPH c reductase and GST were higher in the reproductive than in the non-reproductive season. Differences in enzymatic content or activity in corals from the two parks were usually more prominent during the reproductive season. Hence, P450 and P420 were undetectable during the non-reproductive season, while during the reproductive season, P420 was highest in colonies from the most impacted park (PNM). Activities of NADPH c reductase, CAT and SOD were also higher at PNM than at PNALR, while GST was an exception to this trend. Our results show that the aforementioned enzymes act as biomarkers in the coral S. siderea, changing in relation to its reproductive status and with the habitat quality.