New hammerhead shark species is identified
Miami, FL - Scientists from Nova Southeastern University discovered a new species of hammerhead shark.
Nearly seven years ago, scientists from Nova Southeastern University Oceanographic Center sampling sharks caught on charter boats off Fort Lauderdale stumbled on a startling discovery: some of the sharks that looked like scalloped hammerheads were actually a different, unidentified species.
"Completely genetically different," said professor Mahmood Shivji, head of the Guy Harvey Research Institute and Save Our Seas Shark Center headquartered at the university.
At first, the new species appeared to be just a local oddity. But then it turned up in waters off South Carolina and, later, thousands of miles away off the coast of southern Brazil. The discovery — detailed in the April issue of the scientific journal Marine Biology — means both the scalloped hammerhead and its lookalike could be in grave danger from overfishing.
Hammerheads are sought worldwide mostly for their fins, which are the key ingredient in shark fin soup. Millions have been killed, upsetting the balance of ocean ecosystems in which they are a top predator.
The misidentification of the new species raises even more concerns about hammerhead populations. "If you don't really curtail fishing of the scalloped hammerhead, you'll also overfish a species that hasn't been officially acknowledged," Shivji said. "You run the risk of losing a whole species."
The scalloped hammerhead is on the red list of endangered species under the International Union for Conservation of Nature and Natural Resources. It also is under review by NOAA Fisheries Service to determine whether it should be listed as a threatened or endangered species. The unnamed species is on neither list. But that could change.
Margaret Miller, a NOAA Fisheries biologist, said her scalloped hammerhead review team is aware of the new research and will factor it into its recommendation, due in August, on whether to designate extra protection for the species.
Currently, hammerheads are legal to harvest under a commercial quota system in federal waters off Florida and elsewhere, but the Florida Fish and Wildlife Conservation Commission recently banned their harvest in state waters.
Few but trained scientists can tell the scalloped hammerhead from its lookalike. Besides DNA, the only physical difference is the new species has fewer vertebrae.
> LONDON - There's good and bad shark news. The good news is that a new, as of yet unnamed, species has been discovered. The bad news is that it looks just like the scalloped hammerhead shark, curtailing efforts to save that endangered species.
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> The new look-alike hammerhead is identical to its near twin save for a few important differences:
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> •distinctive DNA
> •20 fewer vertebrae (about 170 versus 190)
> •a genetic profile suggesting it separated from the scalloped hammerhead 4.5 million years ago
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> That's an incredibly long period of time, considering how similar the two different sharks look externally.
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> Adding to the confusion is that the new mysterious species seems to have a large range. It was originally discovered off the eastern U.S. Now a paper in the April issue of Marine Biology mentions it's been found more than 4,300 miles away near the coast of southern Brazil.
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> The look-alike species may face the same fishery pressures as the real scalloped hammerhead, which is being fished unsustainably for its highly prized fins.
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> "It's a classic case of long-standing species misidentification that not only casts further uncertainty on the status of the real scalloped hammerhead but also raises concerns about the population status of this new species," Mahmood Shivji said in a press release.
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> He oversaw the new research at the Nova Southeastern University Oceanographic Center's Save Our Seas Shark Center and Guy Harvey Research Institute.
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> "It's very important to officially recognize, name and learn more about this new hammerhead species and the condition of its populations through systematic surveys," he added. "Without management intervention to curtail its inadvertent killing, we run the risk that overfishing could eradicate an entire shark species before its existence is even properly acknowledged."
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> At least 7 percent of the sharks in U.S. waters originally thought to have been scalloped hammerheads now turn out to be the new species. This means that the population of the endangered real scalloped hammerhead in American waters is probably smaller than originally thought.
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> This latest discovery about the twin species could (and should, in my opinion) influence how the U.S. National Marine Fisheris Service classifies the scalloped hammerhead (Sphyrna lewini). Depending on what's decided, this shark could be listed as threatened or endangered. The species is already on the IUCN Red List of Endangered Species.
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> The new "twin" shark may also be endangered, but it's not officially protected yet.
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> Shivji concluded, "We hope that during this important scalloped hammerhead status review, the new look-alike species will be recognized, and possible impacts of historical mix-ups between the two species on past scalloped hammerhead stock assessments will be considered."
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> Keep in mind that we are part of this food chain too, with our bad decisions coming back to bite us. Human overfishing of scalloped hammerheads has caused the cownose ray population to rise. The rays, in turn, are eating more of their fave food, bay scallops. These are the same scallops that many humans like to eat, so the supply of scallops for us is now in jeopardy.
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