Share

Mystery of Mass Whale Grave in Chile Solved

By Michele Berger
Published: February 27, 2014

 

When a road construction crew began to expand the two-lane Pan-American Highway in the Atacama Desert in Chile in 2010, a mass grave of marine mammals was almost lost to history. Thankfully, 3-D digitization tools and an international collaboration of researchers preserved the placement of those skeletons, allowing a unique glimpse into ancient food webs.

Now, a paper published February 25 in The Proceedings of the Royal Society B reveals how these animals likely died: a harmful algal bloom event.

“The answer comes from two major bodies of evidence: One is the orientation arrangement of the skeletons. They’re complete. In some cases they’re overlapping,” Nicholas Pyenson, lead paper author and a paleobiologist at the Smithsonian Institution, told weather.com. The other is the fact that the bones — which encompassed more than 40 skeletons and a great diversity of species, including two animals extinct today — were found in four layers rather than just one. The majority of the creatures were baleen whales, but there were also seals, aquatic sloths, even predatory fish.

Researchers used 3-D digitization tools to study a massive whale grave discovered in Atacama, Chile in 2010. Today, we understand a harmful algal bloom likely caused the mass die-off. (Smithsonian Institution)

“Whatever case you have has to explain all those facts,” Pyenson said. “The cause that holds out the best is sudden death by toxins by harmful algal blooms.”

Blooms of this type affect marine mammals even today; they ingest the toxins or eat prey that has. But we typically don’t know that’s the cause right away because it takes time to parse this out, often leaving the reasons behind mass strandings a mystery. That, Pyenson added, is one of the benefits of working at a geologic scale. “You don’t get a complete picture of life in the past, you just get these snapshots, but sometimes the snapshots are coarsened up that you can actually figure out with a large degree of certainty what happened.”

This is crucial in the case of the Atacama bones because there are still, by the scientists’ estimates, hundreds of skeletons at the site, dubbed Cerro Ballena or “Whale Hill.” They’re visible today thanks to the very highway that threatened to destroy the original mass grave. (The original bones ended up in two museums in Chile, in Santiago and in a town called Caldera.)

The researchers date the bones back some 6 to 9 million years. “It’s the richest and densest fossil whale site in the world,” Pyenson said. And thanks to some cool technology and some persistent scientists, today we have a more complete picture of what happened to these animals.

Read the full paper, “Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea,” in The Proceedings of the Royal Society B here.

MORE: Today’s Top Videos 


Featured Blogs

Isis, Odile Removed from Northeast Pacific Tropical Cyclone List

By Dr. Jeff Masters
April 20, 2015

The Northeast Pacific list of hurricane names got a shake-up on Friday, when the U.N.'s World Meteorological Organization (WMO) voted to remove the name "Isis" because of its potential confusion with the Islamic militant group, the Islamic State of Iraq and ash-Sham (ISIS). In addition, the name "Odile" was retired for the death and destruction Hurricane Odile caused in Baja, Mexico in September 2014.

The Great California Storm of April 19-23, 1880

By Christopher C. Burt
April 11, 2015

Could a single big late–season storm have a significant impact on the California drought? A 'Hail Mary' storm event? Normally by this time of the year (April 10th) California would have already received at least 90% of its rainy-season precipitation total and any additional rain or snowfall would have little impact so far as the current drought is concerned. However, back in late April 1880, one of the most intense storms ever to pound the state occurred. Here are the details.

Please check out the new homepage and tell us what you think!

By Shaun Tanner
April 2, 2015

The development team here at Weather Underground has been hard at work producing a new homepage! Please take a look at the sneak peek and tell us what you think!

Meteorological images of the year - 2014

By Stu Ostro
December 30, 2014

My 9th annual edition.

2013-14 - An Interesting Winter From A to Z

By Tom Niziol
May 15, 2014

It was a very interesting winter across a good part of the nation from the Rockies through the Plains to the Northeast. Let's break down the most significant winter storms on a month by month basis.

What the 5th IPCC Assessment Doesn't Include

By Angela Fritz
September 27, 2013

Melting permafrost has the potential to release an additional 1.5 trillion tons of carbon into the atmosphere, and could increase our global average temperature by 1.5°F in addition to our day-to-day human emissions. However, this effect is not included in the IPCC report issued Friday morning, which means the estimates of how Earth's climate will change are likely on the conservative side.