“Great hammerheads are remarkable creatures, but they are in dire need of assistance from federal authorities. They are being ruthlessly hunted for their fins and falling victim to high mortality rates due to gillnets and other fishing equipment. By implementing protections under the Endangered Species Act, we can ensure that future generations have the opportunity to witness these extraordinary beings in their natural habitats. Unless immediate action is taken, great hammerheads face a bleak future,” emphasized Emily Jeffers, an attorney from the Center for Biological Diversity, in a petition submitted in 2022 to safeguard this critically endangered species of hammerhead shark, as recognized by the International Union for Conservation of Nature (IUCN).
Great hammerhead sharks (Sphyrna mokarran) belong to the genus Sphyrna, which comprises nine species of hammerheads. Although there is insufficient data for some of these species to assess their population status accurately, certain hammerhead species, such as the Golden hammerhead, Winghead shark, and Scalloped hammerhead, are already categorized as vulnerable or endangered. Notably, the Scalloped hammerhead is the first documented cold-blooded fish capable of “holding its breath” underwater.
The Great Hammerhead Shark is the largest among the hammerhead species, capable of reaching lengths of up to 20 feet and weighing nearly 500 kilograms. It inhabits tropical and temperate coastal waters in various regions, including the Pacific Ocean, Indian Ocean, Caribbean Sea, Mediterranean Sea, Atlantic Ocean, and the Gulf of Mexico. Its diet primarily consists of crustaceans, cephalopods, bony fish, skates, and particularly stingrays.
The distinguishing feature of this shark is its hammer-shaped head, also known as a cephalofoil. This unique adaptation allows it to have a panoramic 360° field of vision through stereoscopic vision. Additionally, the underside of the cephalofoil is lined with Ampullae of Lorenzini, small tubular structures filled with jelly-like substance that enable the shark to detect electrical fields emitted by other marine organisms. Comparable to a highly sensitive metal detector, the hammerhead shark can perceive the heartbeats of small fish and detect the presence of hidden stingrays beneath the sand using its exceptional electrosensory organ.
However, despite their remarkable abilities, the global population of Great hammerhead sharks has experienced a significant decline. According to SharkSider, “Although Great Hammerhead Sharks are not specifically targeted in commercial fishing, they frequently become unintentional catch. While humans highly value the fins of these sharks, they also consume various parts of their bodies, including fresh, dried, salted, fresh-frozen, and smoked meat. The oil extracted from their livers is used for vitamin production, their carcasses are processed into fish meal, and their hides are utilized for leather. The fins, in particular, hold immense value due to the demand for shark fin soup.”
While a fisherman may not have intentionally caught this 14-foot pregnant female Great hammerhead, the unfortunate incident led to the shark’s death in Orange Beach, Alabama. Several individuals assisted in bringing the carcass ashore and promptly notified the City of Orange Beach Coastal Resources, who subsequently contacted the Mississippi State University Marine Fisheries Ecology for a necropsy examination.
It was discovered that the massive great hammerhead shark was carrying a litter of 40 shark pups, all of which were deceased like their mother.
As stated in the Mississippi State University Marine Fisheries Ecology’s Facebook post, “We are aware that great hammerhead sharks are particularly susceptible to the physiological effects of stress caused by capture, more so than most other shark species. Pregnancy exacerbates this physiological stress. Therefore, we suspect that fishing activity was the cause of death.”
In fact, as reported by Earth.Org on its own platform, great hammerhead sharks exhibit the strongest fight-or-flight response compared to all other shark species. This contributes to their 90% post-capture mortality rate due to the detrimental impact of extreme stress on their bodily functions.
However, the loss of both the great hammerhead mother and her pups was not in vain, as valuable data was obtained by the university for their research endeavors. The team of scientists has also preserved the unborn shark pups for donation to local classrooms, serving as educational resources.
Regarding the request made by the Center for Biological Diversity to “classify the great hammerhead shark as a threatened or endangered species under the ESA and establish critical habitat alongside the designation,” the United States National Marine Fisheries Service (NMFS) held a different perspective, much to the disappointment of the scientific community.
The government believes that its ongoing initiatives and efforts have been effective in ensuring a thriving population of great hammerhead sharks. According to the NMFS, the petitioner did not present new evidence demonstrating that climate change, ocean acidification, and coastal development have an impact on the great hammerhead sharks. Furthermore, the 2019 IUCN classification of great hammerheads as critically endangered was insufficient evidence to support the petitioner’s assertion that overexploitation posed a threat to this specific shark species.
Upon reflecting on this narrative, one cannot help but wonder how many hammerheads and shark pups must perish before the government deems the situation worthy of greater protection for these marine creatures. Hasn’t the world learned from the plight of species like the vaquita, totoaba, and delta smelt, among many others, which are nearing extinction with countless others lost forever?
Rewritten Source: https://blog.theanimalrescuesite.greatergood.com/hammerhead-shark-pregnant-pups/