Amazon River Fish Face Multiple Crises

Why this is here: Fish collected from the Negro River after a 2013 oil spill still show genetic damage over a decade later, revealing lasting chemical impacts.

Researchers in Brazil document how pollutants, droughts, and hydroelectric dams are irrevocably changing Amazonian rivers and the fish within them. Riverine and Indigenous communities report dwindling fish populations, smaller sizes, and increasing deformities, observations now confirmed by scientific study. The Mongabay series details impacts across the Amazon basin, from the Madeira River to the Xingu and Negro Rivers.

Fishermen near the Santo Antônio and Jirau dams on the Madeira River partnered with scientists to map damage to fish stocks like pirarucu and tambaqui. On the Xingu River, scientists link the Belo Monte dam to unusual fish deformities caused by altered river flooding patterns. A 2013 oil spill on the Negro River continues to affect fish DNA even after the visible oil dissipated.

Recent extreme droughts exacerbate these problems, impacting fish reproduction and growth, and threatening the primary protein source for many Amazonian people. While studies identify these issues, solutions and protective actions remain limited. The work to understand these complex changes continues.