More than 300 whales have been found washed up in a remote inlet in Patagonia in southern Chile in one of the largest die-offs on record. Picture: Vreni Haussermann/Huinay Scientific Field Station/AFP

Biologist Vreni Haussermann told The Associated Press Tuesday that she made the discovery along with other scientists in June during an observation flight over fjords in Chile’s southern Patagonia region.

“It was an apocalyptic sight. I’d never seen anything like it,” said one of the scientists who made the discovery, Vreni Haussermann of the Huinay Scientific Centre.

A dead Sei whale lies in Caleta Buena, in the southern Aysen region of Chile. Picture: Vreni Haussermann/Huinay Scientific Center/APSource:AP

Scientists launched an expedition to count the animals after 20 sei whales were reported dead in April, beached in an extremely remote region some 2000km south of the capital Santiago.

When the researchers flew over the region in June, they found the scale of the die-off was much larger: at least 337 dead whales, “including bodies and skeletons,” said Haussermann.

“There are still a lot of areas we haven’t managed to reach, so it’s likely there are more dead whales,” she told AFP.

Scientists initially said the whales did not bear any wounds, suggesting they may have died of a virus or a harmful algal bloom known as “red tide.”

Sei whales lie dead at Caleta Buena, in the southern Aysen region of Chile. Picture: Vreni Haussermann/Huinay Scientific Center/APSource:AP

The gruesome find comes as countries get down to tough negotiations at crunch talks in Paris, which are seeking a pact to curb climate change.

Marine biologists say the warming of the world’s oceans is putting dangerous pressure on whale populations by killing off their food supply and changing their age-old migratory routes.

Further conclusions from the study will be released in an upcoming issue of National Geographic, who funded the expedition.