Health Assessment of Two Coastal Elasmobranch Species from the Northeast Region of Brazil

Elasmobranchs, including 79 shark and 120 ray species worldwide, face severe endangerment due primarily to fishing pressures and marine pollution. This study investigates the health of fishery resources affected by the 2019 oil spill in Northeast Brazil, focusing on histopathological changes in the liver, kidney, and gills, as well as the presence of polycyclic aromatic hydrocarbons (PAHs) in the muscle tissue of Rhizoprionodon porosus (RP) and Hypanus guttatus (HG). Age and time of exposure to oil (TEO) were estimated, and organ and total histopathologic indexes (Iorg and Itotal) were determined following Bernet (1999). Additionally, lesion severity was assessed using the Zimmerli (2007) approach. Results show that 74% of the 71 elasmobranchs sampled exhibited significant histological changes, with lesion scores exceeding 40, indicating severe, chronic stress. Notably, 54% of these were rays (H. guttatus), with gills identified as the most affected organ across both species. Significant differences in Itotal scores were observed between species, though sex, sexual maturity, age, and exposure time had no significant impact. This pioneering histopathological assessment highlights elasmobranchs as valuable bioindicators and underscores the environmental impact of Brazil's most severe coastal oil spill to date.