In the ocean food chain, large sharks generally only have to worry about keeping orcas at bay — but a new study suggests the apex predators may have to watch out for their own.
Researchers have discovered evidence pointing to the first known case of a porbeagle shark — which can grow up to 12 feet long and 500 pounds — being killed by a large shark predator.
This isn’t the first case of “shark cannibalism,” said Jon Dodd, executive director of the Atlantic Shark Institute, which helped lead the study.
Larger sharks eating smaller sharks is a common occurrence, “in the open ocean, size matters, but there is always something bigger,” he said.
In some cases — bull sharks, mako sharks and baby sand tiger sharks, for example — sharks will even eat their own species.
But cases of large sharks eating other large sharks, the subject of this study, are few and far between, said lead author Dr. Brooke Anderson, a marine biologist for the North Carolina Department of Environmental Quality.
The fatality of the female porbeagle raises questions about whether this incident represents a wider trend among large predators, said Anderson.
The tags stored the data until they eventually fell off the sharks, at which point the data was transmitted back to the researchers via satellite.
“The only explanation for that data is that this tab is now in the stomach of a predator,” Anderson told CBS News.
“Humans heavily rely on oceans for food and many other things and the oceans need healthy shark populations,” Anderson said.
The main concern of large sharks in the ocean food chain is usually preventing orcas from getting too close to them, but a recent study indicates that these top predators may also need to protect their own young.
Researchers have found evidence that suggests this may be the first recorded instance of a large shark predator killing a porbeagle shark, which can reach lengths of 12 feet and weights up to 500 pounds. Frontiers in Marine Science, a journal dedicated to biology, published the findings on Tuesday.
The Atlantic Shark Institute, which assisted in spearheading the study, said that this is not the first instance of “shark cannibalism.” Jon Dodd concurs. In the open ocean, “size matters, but there is always something bigger,” the speaker stated. Larger sharks frequently consume smaller sharks.
Sharks will occasionally even consume members of their own species; bull sharks, mako sharks, and baby sand tiger sharks are a few examples.
The study’s primary author, Dr. Brooke Anderson, a marine biologist for the North Carolina Department of Environmental Quality, noted that there are, however, very few instances of large sharks consuming other large sharks.
According to Anderson, the death of the female porbeagle begs the question of whether this event is indicative of a larger pattern among large predators. “Technological improvements may make it more likely than we’ve been able to find that this occurs frequently,” Anderson said.
“If our experiences at the Atlantic Shark Institute are an indicator, it might be more than we think,” Dodd continued, adding that it is impossible to know how many sharks are eaten by other sharks. ****.
scientists from various U.S. states who are conducting research. S. discovered the porbeagle’s demise while working on a satellite tracking project in the Northwestern Atlantic to learn more about the locations, habits, and preferred environments of the shark species. They were especially interested in female porbeagles because they are known to travel great distances across the ocean to give birth to their young.
According to Anderson, “our main goal was to learn about the habitats that the pregnant females were using and try to determine where they might give birth.”.
The attacker, who the scientists named Penelope, was one of the eleven sharks they tagged off the Cape Cod coast in 2020 and 2022. In order to gather data on water temperature and depth, tracking tags were affixed to the sharks’ dorsal fins. The data was transmitted back to the researchers via satellite after the tags eventually fell off the sharks and stored.
Although the tracking devices were intended to be used for a full year, Penelope’s data began to stream in five months into the experiment. “I knew something odd had happened as soon as I got the data from that tag,” Anderson remarked.
The water suddenly became extremely hot a few days before Penelope’s tag broke off off the coast of Bermuda. Even when it dropped to 600 meters below sea level, it stayed relatively high, which Anderson described as “very unusual.”.
Following some terrifying research, Anderson and her colleagues discovered that another sea monster had hunted and devoured the porbeagle. Anderson told CBS News that “the only explanation for that data is that this tab is now in the stomach of a predator.”.
Although the exact identity of the offender is unknown, the predator’s diving pattern, which was tracked by researchers using the tag’s depth data, resembled that of white sharks they have previously studied. “That leads me to believe that it was probably a mature female white shark,” Anderson remarked.
Due to historical overfishing, porbeagles are threatened in some regions of the world. As they are already in danger, Anderson warned that the loss of pregnant women and their offspring could have catastrophic effects on the populace.
Furthermore, this shift may have repercussions that are felt by creatures other than sharks. By supplying vital nutrients to shallow waters and controlling smaller predator populations, the deep-diving apex predators preserve the equilibrium of the underwater ecosystem.
Anderson stated, “Humans rely heavily on the oceans for food and many other things, and the oceans need healthy shark populations.”.
