New York has a dense population. Close to 20 million people call the state home, and over 8.4 million are concentrated in New York City. It’s a testament to urbanization, a city defined by its flourishing cultural and business quarters. But Jon Dohlin, the vice president and director of the Wildlife Conservation Society’s New York Aquarium, sees another bountiful aspect of the area, and it lies in the coastal waters.
“New York more than almost any other maritime city—it seems to me and my colleagues—has sort of lost that sense of being a maritime city,” Dohlin says in an interview with R&D Magazine. “It doesn’t have the same feel as say Boston, or Seattle, or even San Francisco, great cosmopolitan cities that still fundamentally define themselves as maritime cities.”
But sometimes all it takes to change the widespread conception about a place is a scientific discovery, something that can reawaken that sense of awe and wonderment at the natural environment beneath the concrete surface.
In Long Island’s Great South Bay, scientists and veterinarians from the Wildlife Conservation Society’s New York Aquarium have discovered a nursery ground for the sand tiger shark, a sleek and docile creature with dagger-like and ferocious teeth.
For years, local anglers and boaters had spotted and caught juvenile sand tiger sharks in the area. The anecdotal evidence was bolstered in 2011, when one of the aquarium’s scientists received a picture of a dead shark, suspected to be a sand tiger shark. “It’s all about listening to people who live on the water, who work on the water, who are constantly interacting with the coastline…and listening to the wisdom and knowledge they have from the work that they do,” says Dohlin.
Following up on such tips gave Dohlin and colleagues the opportunity to quantify that anecdotal knowledge. Armed with a location, the team concentrated their efforts on the bay and proceeded with a tagging study. According to the Wildlife Conservation Society, 15 of the tagged sharks ended up returning to the Great South Bay in subsequent seasons, a behavior known as site fidelity.
Ranging in size between 6.5 and 10.5 ft in length, sand tiger sharks have a wide distribution, being found in many of the world’s warm and temperate waters near coastlines. Slow swimmers, the rust-colored sharks are docile, feasting on small fish, and are only known to attack humans if bothered first, according to National Geographic. But like many sharks and rays, these creatures are threatened, and are classified as a “Species of Concern” by the U.S. National Marine Fisheries Service. Fishing of the sharks in state and federal waters has been prohibited since 1997.
According to Dohlin, sand tiger sharks have a low reproduction rate, only giving birth to one or two pups each year, or every other year. And when born, they only measure around 11 to 12 in, making them quite vulnerable to predation. In order to ensure they reach adulthood, they need backwater areas, where they can grow and thrive until reaching maturity.
“At three to four years of age, when they’re no longer considered juvenile and they’re about 4 to 5 ft long, they (can) move out into open coastal waters,” says Dohlin.
Dohlin and colleagues believe the sharks are born somewhere off the coast of the southeastern U.S., perhaps in the Chesapeake Bay region or the Carolinas.
“We know that they continue to move seasonally,” he says. “What we don’t know is where they go down south,” whether the location is another nursery or not.
“Are they constantly moving back and forth between nurseries? We don’t really know that, and we don’t know…the key components of this habitat that make it so suitable for their growth,” he adds. “Instead of constantly moving as the adults do,” the juveniles have these controlled sites.
There are still many questions, and Dohlin and his team are expanding their dataset to find the answers.
The information learned will go on to inform a new shark exhibit, which is part of a $150 million renovation project at the New York Aquarium.
This is a chance to revel in the “power and charisma of sharks,” he says.
