Mass Fish Egg Die-Off Reported Below Belo Monte Dam in Brazil's Xingu River

Mass Fish Egg Die-Off Discovered in Xingu River

A widespread die-off of fish eggs was recently discovered below the Belo Monte Dam in the Volta Grande stretch of Brazil's Xingu River, located in the state of Pará. Researchers and local residents found large quantities of eggs exposed on soil, leaves, and branches, indicating no chance of survival. Images recorded on Saturday, February 21, 2026, by a regional monitoring system, documented the extent of the tragedy.

Experts are linking this environmental incident directly to the operating regime of the Belo Monte hydroelectric plant, which has significantly altered the natural hydrological patterns of the river.

Dam's Operation Disrupts Vital Flood Cycles

The Belo Monte Dam, one of the world's largest hydroelectric facilities, diverts more than 80% of the Xingu River's water to its reservoir, drastically reducing the flow over approximately 100 kilometers of the river. This diversion disrupts the natural pulse of floods and droughts that historically connected the river to its flooded forest areas, known as igapós, which are crucial for fish reproduction. The reduced water flow prevents these igapós from flooding adequately, hindering the spawning and development of many fish species.

This current event is not isolated; researchers have warned that this pattern of environmental degradation, particularly affecting fish reproduction, has been documented annually since 2023.

Long-Term Environmental and Social Impacts

The operation of the Belo Monte Dam, which became operational in 2016, has been a source of continuous environmental and social controversy. Previous incidents include a significant fish die-off in 2016, for which the dam's concessionaire, Norte Energia, was fined. Studies and monitoring efforts by independent groups and federal prosecutors have also reported a high prevalence of deformities in fish in the Volta Grande do Xingu, with potential causes including nutritional deficiencies, altered aquatic habitats, and reduced oxygen levels due to stagnant waters.

Local fishing communities and indigenous peoples, whose livelihoods depend on the river's health, have reported a drastic decline in fish populations and changes in traditional fishing practices. Federal prosecutors have warned of an 'ecosystem collapse' in the region due to the dam's impacts. In response to the latest die-off, Norte Energia stated it has forwarded information about the occurrence to specialists and that the findings of the investigation will be sent to authorities.