Hundreds of baby whales die off Argentina; bacteria suspected

A bacterial infection is suspected in the deaths of hundreds of southern right whale calves off Argentina’s Patagonia region, where dozens more dead calves washed up this week in southern Chubut province.

Mariano Coscarella, a researcher at the Marine Mammals Laboratory of Argentina’s national research council Conicet, told AFP that the death rate among young whales was “quite high” this season.

Coscarella said veterinarians suspected an outbreak of erysipelas, a serious disease caused by bacteria commonly found on the mammals’ skin. He said the cause appeared to be natural, but that the influence of human activity could not be completely ruled out.

The Chubut provincial government said Wednesday that it was working with scientists to investigate the deaths. It said preliminary research suggested a “common marine bacteria” was involved.

Puerto Madryn and the nearby Valdes Peninsula are major breeding grounds for southern right whales. Coscarella said 1,375 whales had been counted in the area this year, including nearly 400 calves, down from a record 2,110 whales in 2025, including 800 young.

Coscarella said the recent deaths did not pose a medium-term danger to the area’s whale population, given the species’ average life span, which local authorities put at 60 years.