Pictures: Dozens of dead stingrays found on Brazil beach

Dozens of dead stingrays appeared on a beach in Rio de Janeiro this week, sparking confusion and concern in the local community.

Local fishermen reported the first sightings early on Tuesday. A woman who lives in the fishing village said she noticed the incident shortly after dawn, prompting the arrival of vultures.

Remains of dead stingrays are seen at Ilha do Fundao, on the banks of the Guanabara Bay, in Rio de Janeiro.

"This made us all sad. We've never seen the death of stingrays like this here," said fisherman Renato dos Reis Oliveira.

A fisherman holds a dead stingray at Ilha do Fundao, on the banks of the Guanabara Bay. Biologist Ricardo Gomes, from the Mar Urbano Institute, argued the absence of other dead species on the beach indicates the incident was likely not caused by pollutants or a lack of oxygen in the water.

"This makes the hypothesis of trawling more evident in the cases of these stingrays," Gomes said. Trawling is a fishing technique that involves pulling a net through the water behind one or more boats.

"This is not (the stingray's natural) place, so this is strange even for the people who are here and who live off fishing," said environmentalist Isabeli Delois. "Something very bad happened," she added.

Remains of dead stingrays are seen at Ilha do Fundao, on the banks of the Guanabara Bay, in Rio de Janeiro.

Remains of dead stingrays are seen at Ilha do Fundao, on the banks of the Guanabara Bay, in Rio de Janeiro