Histopathology as an Approach to Evaluate the Effect of an Oil Spill on Fishes of the Arroio Saldanha and Rio Iguaçu (Brazil)

ABSTRACT In July of 2000, an accident occurred at the Presidente Getulio Vargas Refinery (REPAR), located in the Municipality of Araucaria, Southern Brazil which involved the spilling of about 4 million liters (25,160 barrels) of crude oil. This was considered the largest oil spill in the history of Brazil. Despite of the use of containment barriers, the oil slick reached a small creek (Arroio Saldanha) and, further downstream, two important rivers in the region (Rio Barigui and Rio Iguacu). In this stretch, the Rio Iguacu and the Rio Barigui are highly polluted, having crossed Curitiba, a city that has 2+ million inhabitants, and several industrial areas. The histopathological study of the gills and liver of 2 species of fishes was used to evaluate the impact of the oil on the fish fauna in the affected rivers. The choice of fish species reflects their year-around availability and their predicted roles in the ecosystem. Astyanax sp. is mainly pelagic and Corydoras paleatus is demersal; these fish species...