Nearly 2,000 penguins have been found dead on Uruguay’s eastern coast in ten days, with the cause of the death toll, which remains unexplained, unlikely to be bird flu, authorities said.

The Magellanic penguins, most of them young, died in the Atlantic Ocean and were washed away by the currents on the coasts of Cannellones, Maldonado and Rocha (south, southeast) prefectures, explained Carmen Laissagogen, responsible for fauna at the Ministry of the Environment.

According to Ms Laisagogen, “90% were young birds”, which washed up on the shores “without fat reserves and with empty stomachs”. Tests to determine whether they had been infected with bird flu came back negative, she added.

This penguin species, which usually nests and breeds in southern Argentina, migrates north in search of warmer waters during the southern hemisphere winter. It can reach as far as the coast of the Brazilian state of Espirito Santo (southeast).

“It’s normal for a percentage to die, but not this big,” Ms. Laisagogen stressed, recalling that a similar death toll was recorded last year in Brazil, and in that case without explaining the cause.

Hector Kaimaris, responsible for the protected lagoon Rotsa, said that more than 500 penguins were counted dead in a ten kilometer stretch of the coast.

Environmentalists attribute the mortality of Magellanic penguins to overfishing and illegal fishing.

“From the 1990s and 2000s we started to see animals that did not have enough food,” said Richard Tesore of the non-governmental organization SOS Rescate de Fauna Marina, highlighting the “overexploitation” of marine resources.

According to him, a cyclone that formed in the Atlantic and hit southeastern Brazil probably led to the death of the weakest seabirds.

In addition to the penguins, Mr. Tesore said many other marine animals were also found dead – including terns, albatross, gulls, sea turtles and sea lions – off the coast of Maldonado, east of the capital Montevideo.