RESUMO
The Fundão Dam collapsed, on November 5th, 2015, dumping more than 50 million/m3 of iron ore tailings, enriched with metals, into the Doce River channel. The objective of this study was to evaluate the reproductive biology and histological damage in Astyanax lacustris specimens exposed to the metals from the dam collapse. The study was carried out at Doce River, in Espírito Santo State, Brazil. Monthly samplings were carried out for a year. Astyanax lacustris had multiple spawning: females' reproductive peak was in September, October, November, and December; and males between September, October, January, and February. There was a latency in the formation of gonads. For male gonads, it was necessary a 6 cm growth for it to increase from 30 to 50% and 4 cm for female gonads to increase from 40 to 50%. There is a positive correlation between gonad's concentration of Al and Fe and the rate of histological damage in females. Male gonads had a high rate of immature cells invading the cell lumen (47.36%) and female gonads showed a higher frequency of atresia (39.64%). Fish exposed to the contaminated water showed moderate-high gonad histological damage. The observed changes can directly influence the organism's development and reproduction in the long run, thus affecting A. lacustris population present in the region.
Assuntos
Caraciformes , Poluentes Químicos da Água , Animais , Brasil , Monitoramento Ambiental , Feminino , Masculino , Reprodução , Rios , Poluentes Químicos da Água/análiseRESUMO
Green sea turtles ( Chelonia mydas ) with cutaneous fibropapillomatosis (FP) occur in some populations worldwide, and the survivability of these individuals may be compromised depending on the disease severity score. Furthermore, populations may be negatively affected in areas with a high prevalence of the disease. The stress responses (corticosterone, glucose, lactate, and hematocrit) to capture and handling were assessed in animals with different FP severity scores. From 18 January 2013 to 31 July 2014, 33 juvenile (sex was not determined) C. mydas were collected from the effluent of a steel mill in the state of Espírito Santo, Brazil, by casting a net from the bank of a canal in the morning. The body conditions of animals with FP scores of FP2 and FP3 were poor, which suggests that these turtles were unable to adequately feed themselves, and animals with an FP score of FP3 exhibited an impaired corticosterone response. This may compromise the fitness of animals in populations with a high incidence of advanced-stage FP.