“Great hammerheads are magnificent, but these huge, iconic animals desperately need federal help. They’re being slaughtered for their fins and killed in great numbers by gillnets and other fishing gear. With Endangered Species Act protections, we can ensure the next generation will see these amazing creatures in the wild. Great hammerheads won’t be around much longer unless we act now, ” said Emily Jeffers, an attorney with the Center for Biological Diversity, in a 2022 petition to protect this hammerhead shark species that’s been listed as critically endangered by the International Union for Conservation of Nature (IUCN).
Great hammerhead sharks (Sphyrna mokarran) are one of the nine species of hammerheads under the genus Sphyrna. While we lack adequate data for some of them to determine population health, there are hammerhead species that are now considered vulnerable and endangered, such as the Golden hammerhead, Winghead shark, and Scalloped hammerhead — the first-ever cold-blooded fish to have been documented with capability to “hold its breath” underwater.
The Great Hammerhead Shark is the largest of the hammerhead species, which can grow up to 20 feet and weigh up to almost 500 kilos. It lives in the tropical and temperate coastal waters of the Pacific Ocean, Indian Ocean, Caribbean Sea, Mediterranean Sea, Atlantic Ocean, and the Gulf of Mexico. Its diet consists of crustaceans, cephalopods, bony fish, skates, and especially stingrays.
And yes, this shark’s hammer-shaped head — also called cephalofoil — is its most precious body part, enabling it to have a 360° field of view in stereoscopic vision. What’s more, the underside of the cephalofoil is covered with Ampullae of Lorenzini, tiny tubes with jelly-like stuff that can quickly detect electrical fields coming from other marine creatures. Just like a highly-sensitive metal detector, a hammerhead shark can sense even the heartbeats of small fishes and the presence of stingrays hidden under the sand with its extraordinary electrosensory organ.
However, in spite of these amazing abilities, the population of the Great hammerhead sharks has drastically declined globally. According to SharkSider, “Great Hammerhead Sharks are not particularly targets for commercial fishing, however they are often bycatch victims. Humans treasure the fins of these sharks, but they also consume fresh, dried salted, fresh-frozen, and smoked meat that are taken from other parts of the Great Hammerhead Sharks’ bodies. In addition, the oil from the livers is used for vitamins, their carcasses are turned into fish meal, and their hides are used for leather. The fins are extremely valuable because of the love of shark fin soup.”
A fisherman might not have meant to catch this 14-foot female great hammerhead, but the pregnant fish ended up dead in Orange Beach, Alabama. Several people pulled the carcass to the shore and contacted the City of Orange Beach Coastal Resources which in turn got in touch with the Mississippi State University Marine Fisheries Ecology for necropsy.
It was found that the large great hammerhead was pregnant with 40 shark pups, all of them dead like their mother.
According to the Mississippi State University Marine Fisheries Ecology’s post on Facebook, “We know that great hammerheads are especially prone to the physiological effects of capture stress, more so than most other shark species. Pregnancy compounds this physiological stress. Consequently, we suspect death was the result of fishing mortality.”
Indeed, as Earth.Org shared on its own website, the great hammerhead sharks appear to have the strongest fight-or-flight response among all shark species. This contributes to their 90% post-capture mortality rate due to the impact of extreme stress on their bodily functions.
But the death of both great hammerhead mother and pups was not completely in vain because the state university was able to gather important data that would help their research work. The team of scientists have also preserved the unborn shark pups for donation to local classrooms for educational purposes.
As for the petition of the Center of Biological Diversity to “list the great hammerhead shark as a threatened or endangered species under the ESA and to designate critical habitat concurrent with the listing,” the United States National Marine Fisheries Service (NMFS) disagreed with the petitioner, much to the disappointment of the scientific community.
For the government, its ongoing programs and endeavors have been effective enough to ensure a thriving population of great hammerheads. According to NMFS, the petitioner failed to present new evidence that climate change, ocean acidification, and coastal development have an impact on the great hammerhead sharks. And the 2019 IUCN listing of great hammerheads as critically-endangered was not proof enough to support the petitioner’s claim that overexploitation was a threat to this particular shark species.
Thinking this story through, you can’t help wondering how many hammerheads and shark pups must die before the government would consider the situation serious enough to warrant more protection for this marine life. Hasn’t the world learned its lessons yet from the fate of the vaquita, totoaba, and delta smelt, along with many other species nearing extinction, with countless gone forever?