Janice R. Andrews
It is a huge surprise to everyone in the scientific world that experts have found proof of an 8-foot porbeagle shark being eaten by an unknown animal. It is the first time that we know of that a top-level predator has killed a bottom-level predator. The results were released on Tuesday in the peer-reviewed journal Frontiers in Marine Science. They show a dramatic event that happened deep in the ocean.
A Groundbreaking Study on Sharks in Danger
Scientists from Oregon State University, Arizona State University, and the Atlantic Shark Institute in Rhode Island were part of the research team. Their first goal was to look into how pregnant porbeagle sharks move. In many parts of the world, these sharks are considered rare. To help protect them, scientists need to learn more about how they behave and where they go on vacation. An 8-foot porbeagle shark was under study. It was tracked for five months as it moved from New England to Bermuda.
The Unexpected Attack by a Predator
The team led by James Sulikowski, who is in charge of the Coastal Oregon Marine Experiment Station at Oregon State University, kept an eye on the sharks using two kinds of tags. The first, a finmount tag, gave exact location information every time the shark’s fin broke the surface of the water. The second tag, a pop-off satellite archive tag, recorded temperature and depth information that was very helpful in figuring out where the shark lived and how it moved.
The archive tag was the first sign that something strange had happened. The tag picked up a rapid rise in temperature from 15°C to 25°C while the shark was moving between 1,640 and 3,280 feet deep. This sudden change made it look like a warm-blooded animal had eaten the shark.
“We knew something took place,” Sulikowski told USA TODAY. “We knew the tag was inside a living thing with warm blood…” We were sure it wasn’t a whale or other animal because mammals are much warmer.
It’s likely that another shark did it.
The temperature readings and the facts of the case led the experts to believe that the attacker was most likely another shark, preferably one from the lamnid family. There are porbeagles in this group, as well as the more well-known white sharks and mako sharks. The body temperatures of these species are usually between 25°C and 27°C, which means they have warm blood.
Sulikowski said, “I think it was a mako or a white shark because they can get bigger than a porbeagle.” It’s especially shocking because people used to think that porbeagle sharks, as top hunters, didn’t have many natural enemies besides people.
A Second Strange Event
The researchers didn’t stop there with their results. Another shocking event happened with a second porbeagle shark that was tagged and followed by the same team. It also died in a strange way. About a year after the first event, this shark suddenly fell to the ocean floor while moving at a depth of about 1,968 feet. This shark was not eaten like the first one. It looked like it had been killed because its body sank to the bottom before the tag came back up three days later.
“About a year apart, both sharks were attacked at about the same depth, in about the same place,” Sulikowski said, pointing out how strangely similar the two events were.
What this means for marine science
These events make us think deeply about how big sharks behave and how sea ecosystems change over time. It’s a stark reminder of how little is known about the ocean’s deep, Sulikowski said, that a big, fast-swimming shark like a porbeagle could be killed by another predator.
Sulikowski said, “Because sharks are so big and fast, the only animals that will eat them are other sharks that are bigger than them.” „The fact that this took place shows how little we understand about the ocean.”
Because of what the research team found, people are once again interested in studying marine predators, especially to find out which species really rule the deep ocean. Scientists are still trying to figure out what the ocean is hiding, but this discovery is a strong reminder of how complicated and often surprising the relationships are below the waves.
This important finding not only helps us understand how sharks hunt, but it also shows how much more study is needed to fully understand the complex food webs of the ocean. Many secrets are hidden in the ocean’s depths, and this study is just the start of finding out more about the top predators that live there.
