Megalodon, the massive shark that ruled the world’s oceans for more than 20 million years before dying out 2 million years ago, has been a focus of research for UC Merced assistant professor Sora Kim.
And now her knowledge on the topic will get a wider audience — Kim and other experts will be featured on Discovery Channel’s Shark Week in a show called “Jaws vs. The Meg” that will air starting Sunday.
Kim didn’t know she would wind up being a megalodon expert when she was an undergraduate geology student at Dartmouth College, but when a U.S. Geological Survey geologist dug into a bank of the Chesapeake Bay in Maryland and unearthed a megalodon tooth, her interest was piqued, especially when she thought about a new way of studying it.
“I specialize in a method called stable isotope analysis, which most people don’t know anything about,” she said with a laugh. “And it is a way that we study what modern animals are eating or they might be moving. And then we also use the same method to study ancient organisms as well plants and animals and soils.”
A New Way to Look at Old Bones
Kim, whose research interests are paleoecology, climate change, environmental reconstruction, and stable isotope biogeochemistry, was interested in applying stable isotope analysis to research she was working on as a graduate student at UC Santa Cruz.
“I had this somewhat random idea that we could use it for fossils, shark teeth, because there were a lot of fossils, shark teeth around, and no one … had really probed what sharks were doing in the past with this method.”
Over the years her interest in megalodon has continued to grow.
“I have to say, as the research has gone on, I’ve become more and more fascinated with megalodon, which I was not necessarily expecting. It is also the same in terms of how my journey has been with sharks. I did not start off as someone who was like, I’ve got to study sharks, I’m obsessed with sharks. But sharks are in fact quite fascinating in how they’ve been able to survive for so long. I think the most interesting and surprising work has been, we’ve been trying to develop these new methods to sort of see how high on the food chain Megalodon ate.”
The results were somewhat unexpected, especially in the variation in megalodon teeth and how warm-blooded the ancient shark was, Kim said.
Shark Shows Proliferate
Kim says people are fascinated by sharks, perhaps more so than other marine animals.
The public’s interest in megalodon and in sharks in general also has been fueled by shows like Shark Week on Discovery and Sharkfest on the National Geographic channel and also popular movies like “The Meg” and “Sharknado.”
“It’s really incredible how sharks capture the imagination and curiosity and maybe also play upon the fear of people, because there’s no other group of organisms that have two weeks of popular programming dedicated to them,” Kim said.
Scientists believe megalodons were about 50 to 60 feet long — that’s like two school buses — and two to three times the size of great white sharks, Kim said. Its size helped it stay at the top of the food chain for millions of years, but that size, and also its warm blood may have led to its demise, she said.
About 2.5 million years ago there was a period of climate change when “ocean gateways were opening and closing,” which affected the diversity and abundance of some marine animals, Kim said.
“When you’re that large and you have a high metabolic rate (because of warmer blood), you just have to eat a lot. And so if the environment is shifting and maybe your prey are becoming less abundant or changing where they’re at, that will sort of affect your ability to survive and maybe affect the competition that you have with other organisms around,” she said. “Another organism that happened to be around, that was today’s great white shark.”
Jaws v. The Meg
And what about that match-up between The Meg and Jaws? Back in the day, megalodon’s size advantage would have given it primacy over its great white shark adversaries.
But despite the number of horror films that depict ancient megalodons still lurking in the ocean’s depths, Kim says great white sharks have nothing to worry about. (Not as if they look like they worry about much.)
“While there are many parts of the ocean that are less explored, I think the sheer size of megalodon and what we know about shark ecology makes it impossible that we have not found megalodon if it’s still living,” she said.
Kim says she enjoys paddling around her backyard pool and also trips to the ocean, even though she knows that she may be sharing a patch of water with a known killer.
But sharks typically don’t find humans that tasty, Kim said.
“I actually do love the ocean. I find it very soothing and wonderful,” she said. “But I often wonder what is lurking below the water. And I’ve seen a lot of drone footage, even off the coast of California, of what’s out there.
“But in fact, I think that sharks are more scared of us than we should be of them. We have definitely done a lot more damage to their habitat and their lives than they have done to ours.”