Use of the gonadal tissue of the sea urchin Paracentrotus lividus as a target for environmental contamination by trace metals

Many environmental monitoring works have been carried out using biomarkers as a tool to identify the effects of oil contamination on marine organisms; however, only a few studies have used sea urchin gonadal tissue for this purpose. Within this context, the present work aimed to understand the impact of an oil spill, proposing the use of sea urchin gonadal tissue as a biomarker for environmental contamination by trace metals in the species Paracentrotus lividus. Biometric analysis, quantification analyses of the elements Cd, Pb, Ni, Fe, Mn, Zn, and Cu, as well as histopathological evaluations were performed in gonads of P. lividus collected from an area affected by hydrocarbons, named as impacted shore (IS) and an area not affected, named reference shore (RS). The results showed that carapace diameter (DC), total wet weight (WW), and Cd concentrations in the gonads were significantly influenced by the interaction between the rocky shores of origin, the months of sampling, and by the sex of the individuals. Moreover, from July until September, the levels of Zn and Cd were significantly lower in male than in female gonads. In July (the month of the oil spill), the indexes of histopathological alterations (IHPA) of membrane dilation were significantly higher in individuals from the IS, compared to the individuals from the RS. In addition, there were significant correlations between biometric variables (wet weight, diameter of carapace, gonadal weight, and gonadosomatic index) and the elements Cd, Cu, Ni, and Mn concentrations. Lastly, a delay in the gametogenic cycle of the sea urchins from IS was also observed. Taken together, these findings suggest that direct exposure to trace metals induces histopathological lesions in P. lividus' gonads and affects its reproductive cycle.

Automated summary

Many studies have used biomarkers to monitor the effects of oil contamination on marine organisms, but few have focused on using sea urchin gonadal tissue. This study investigated the impact of an oil spill on the species Paracentrotus lividus, using quantification analyses and histopathological evaluations. The results showed that the levels of certain elements in the gonads were influenced by various factors, and there were correlations between biometric variables and element concentrations. Additionally, histopathological lesions and a delay in the reproductive cycle were observed in sea urchins from the affected area.