More than 100 dolphins found dead in Brazilian Amazon as water temperatures soar

A fisherman stands on his boat as he navigates near thousands of dead fish that have washed up on the banks of Piranha Lake due to a severe drought in the state of Amazonas, Brazil. Photo / AP

More than 100 dolphins have died in the Brazilian Amazon rainforest in the past week as the region grapples with a severe drought, and many more could die soon if water temperatures remain high, experts say.

The Mamiraua Institute, a research group that’s part of Brazil’s Ministry of Science, Technology and Innovation, said two more dead dolphins were found in the region around Tefe Lake, which is key for mammals and fish in the area. Video provided by the institute showed vultures picking at dolphin carcasses beached on the lakeside. Thousands of fish have also died, local media reported.

Experts believe high water temperatures are the most likely cause of the deaths in the lakes in the region. Temperatures since last week have exceeded 39C in the Tefe Lake region.

The Brazilian government’s Chico Mendes Institute for Biodiversity Conservation, which manages conservation areas, said last week it had sent teams of veterinarians and aquatic mammal experts to investigate the deaths.

Ayan Fleischmann, the Geospatial co-ordinator at the Mamiraua Institute, said the drought has had a major impact on the riverside communities in the Amazon region.

“Many communities are becoming isolated, without access to good-quality water, without access to the river, which is their main means of transportation,” he said.

Fleischmann said water temperatures rose from 32C to almost 38C on Sunday.

He said they are still determining the cause of the dolphin deaths, but the high temperature remains the main candidate.