Biomarcadores histológicos em Sciades herzbergii em regiões portuárias e áreas protegidas na Baía de São Marcos, Maranhão

Abstract

Maranhão has the largest port complex in the country, which generates economic development for the state. However, this activity has caused harm to organisms present in the area. The present study aimed to analyze gill and liver lesions as biomarkers for evaluating the effects of environmental contaminants on Sciades herzbergii populations in São Marcos Bay, Maranhão. The collections were carried out in 2018 in the port region (A1) and on Ilha dos Caranguejos (A2), during the rainy and dry periods, in order to identify possible seasonal variations. A total of 76 fish were collected and their morphometric measurements, total length (Lt), total weight (Wt) and gonad weight (Wg) were taken, in order to perform the weight-length relationship and gonadosomatic index (IGS). Gills and livers underwent routine histological procedures to identify possible injuries due to exposure to contaminants. Analysis of the gills showed a high incidence of injuries in both sexes in the port region in both periods, especially in the rainy season. A high number of necrosis-type lesions was observed in males. Gill lesions were observed in organisms from Ilha dos Caranguejos, but with a low incidence. Analysis of the livers of fish from the port region demonstrated a greater number of responses during the rainy season. On Crab Island, no liver lesions were found. Morphometric measurements varied between sexes, locations and periods. Higher average length and weight were found during drought. Females presented higher values than males. Individuals from A1 had higher average length and A2 had higher average weight. The average K values were higher during the drought and females presented higher values than males. The condition factor (K) always presented higher values in A2. In A1, the IGS values were low and those in A2 were high. Males presented the lowest values. The rainy season presented higher GSI values, but this was not considered significant. S. herzbergii captured in the port region are affected by gill and liver lesions and have impaired gonadal development.