It’s home to almost 8 million people crammed into an area of just 3,630 square kilometers (1,400 square miles), but Long Island is also called home to some slightly more toothy residents. It turns out that despite the island containing nearly 40 percent of New York’s entire population, there’s also space for the fearsome-looking sand tiger shark to grow, as researchers have discovered that the waters of Great South Bay, along the southern edge of the island, are actually a nursery ground for these beautiful creatures.
While they may look terrifying – they can reach up to 3 meters (10 feet) in length, with their menacing teeth protruding from their mouths – the sand tiger shark is a placid, slow-moving beast, with no related human casualties ever reported. This new data on where the sharks grow and develop off the New York coast will provide researchers and conservationists with vital information on how best to protect the species, which has been hit hard by overfishing.
Despite being under protection from 1997, the sharks are incredibly slow breeders, and so the discovery of where their young shelter could dramatically aid in their recovery.
The researchers catching juvenile sand tiger sharks in the Great South Bay. John Delaney/WCS
Scientists were first alerted to the potential of a nursery for the sharks when a juvenile washed up in one of the island's marinas, and after doing a little more digging, they found that fishermen regularly caught the young in the Great South Bay. This enabled the researchers to capture and tag some of the sharks, after which they found that two-thirds of the juveniles returned to the same section of the bay, in what is known as “site fidelity.”
“Sand tiger shark pups are not born here but migrate from down south to spend the summers as juveniles in New York's coastal waters,” explains Dr. Merry Camhi, Director of the NY Seascape program, which is based out of WCS's New York Aquarium, which led the research. “The acoustically tagged animals in our study will help us better understand where the sharks go, their habitat needs, and how we can better protect them.”
Sand tiger sharks are found in temperate and subtropical coastal waters around the world, with total population estimates unknown. The sharks are listed as a “species of concern” by the U.S. National Marine Fisheries Service, and it has prohibited catching them in federal and state waters since 1997. The sharks practise what is known as “intrauterine cannibalism,” in which the strongest embryo in the womb eats its siblings. This means that females only give birth to two pups every two years, making their recovery slow and meaning protection for the species is vitally important.