Fernando Diez
Written by Fernando Diez Marketing Director at Quasar Expeditions

Updated: November 12, 2021
Published: November 30, 2015

Massive Whale Die-Off in Patagonia has become the topic of residents and scientists over the past few months.

National Geographic recently released an article on the shocking news of the discovery of the corpses of 337 dead sei whales in Chile’s southern Patagonia (in a remote fjord between Puerto Natales and the Golfo de Penas). The quantity of corpses has made this event the largest whale stranding ever known to mankind. This has created a great sense of worry in the scientific community, as the cause of death is unknown.

Scientists have not been able to examine the bodies directly because of the rough seas that have made it impossible to reach this remote area up to now. The discovery was made on June 23rd while Carolina Simon Gutstein of the Universidad de Chile and Consejo de Monumentos Nacionales de Santiago was on an observation flight over the area with her colleagues.

Scientists say that from what they can observe from flights, they believe the whales are most likely sei whales, which are an endangered species. They are 50 ton, 64 foot-long whales that inhabit deep waters far from land, and can reach speeds of up to 31 miles per hour, making them the fastest cetacean. They feed mainly on krill and have a lifespan of between 50 and 70 years.

Dead whale laying on the shore of Chilean Patagonia

One of the theories proposed as to why this has occurred is a possible bloom of toxic microorganisms, called a red tide, which has been the cause of the death of whales around this region in the past. But this theory has yet to be proven when scientists are able to examine the corpses directly. About fifteen years ago, some 600 gray whales were stranded on the North American Pacific Coast from Alaska to Mexico, but that occurred over a vast area and over a longer span. In Patagonia, the whales were found close together.

Dead whale with mouth open in Patagonia

The Dead Whales Were First Observed in Patagonia in June From the Air. Photograph by Carolina Simon Gutstein (National Geographic).

To learn more about the different species in Patagonia - Patagonia Animals .

The Dead Whales Were First Observed in Patagonia in June From the Air - Photograph by Carolina Simon Gutstein (National Geogrpahic)
Fernando Diez
By Fernando Diez
Marketing Director at Quasar Expeditions

Hi, I am Fernando and travel is my passion. This passion began with my first trip to the Galapagos Islands in 1986 and later became my work when I started working at Quasar Expeditions. Now the Marketing Director for Quasar and responsible for the creation of the Patagonia Project in Chile, my passion for travel continues to grow to new and exciting destinations in South America.



  • Fernando, I learned of this die off about 6 or more months ago but what I read in the article that was published was that as many as 3000 whales were found along the west South American coast in pockets of hundreds. What you show here is a pocket of hundreds but my concern here is that this is only one of many pockets which could total up to 3000 animals? I’m sorry I can’t give you the author’s name of article but it was also discovered by plane. Do you know any more about this die off?

    • Hi Richard! Thanks for getting in touch. The 2015 Patagonia whale stranding event was the largest on record, with 337 documented Sei whale deaths. The potential number of dead whales along the west coast of South America remains unknown, but it’s possible the number is higher, considering undiscovered carcasses. We keep a close monitor on environmental changes here in our regions of Chile, and will continue to post new findings on our blog. Stay informed by joining our mailing list. Let us know of any updates you may have or if you find that article, we’d love to read it. – Fernando