Search

This study aimed to evaluate the harmful effects of metal accumulation on Astyanax lacustris and their biochemical response when exposed to the metals contained in the Doce River water, Brazil. The study was carried out in the Baixo Guandu region of the Doce River, Espirito Santo state. Samples were collected during the dry and wet seasons. Biochemical alterations were observed in the liver of A. lacustris, with apparent seasonal effects directly related to the high concentration of Al and Fe in this tissue. Despite this, the bioconcentration of metals in the organisms showed seasonal effects only in the gills, as they are the first organ in contact with the contaminated water. The data generated in this study provide an overview of the health of the ecosystem in this region, highlighting the harmful biochemical and metal concentration effects on the population of A. lacustris affected by the Fundao dam failure.

On November 5th, 2015, the Fundão Dam collapsed 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 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 higher frequency of atresia (39.64%). Fish exposed to the contaminated water showed high gonad histological damage. The observed changes can directly influence the organism development and reproduction in the long run, thus affecting A. lacustris population present in the region.