No doubt there are many sharks that call New York Harbor, the Jersey Shore, and the south shore of Long Island home during the summer. From blue sharks, brown sharks, great whites, bulls, threshers, to dogfishes, hammerheads and makos, just to name a few.
Yet not many sharks I know will use our local waters as a nursery, a place where young sharks can swim, feed, and mature safely from predators. I always thought most little sharks stayed down south in warmer waters where they were born. Now all that has changed.
Recently scientists at the Wildlife Conservation Society’s New York Aquarium in Coney Island announced they have discovered a nursery for sand tiger sharks in Great South Bay on Long Island. Located approximately 65 miles from mid-town Manhattan and situated between Long Island and Fire Island, the Great South Bay is a place where juvenile sand tiger sharks collect in mass to feed and grow.
While a nursery for sand tigers has been well known up the coast in Plymouth Bay, Massachusetts by the Massachusetts Division of Marine Fisheries, this is the first shark nursery documented so close to the New York metropolitan region.
The idea of a shark nursery in the Great South Bay first started in 2011. A scientist at the New York Aquarium received a photo of a dead sand tiger shark at a local marina. Over time, scientists learned that people had been catching small sharks in the bay for years. Scientists then began tracking sand tiger sharks with acoustic transmitters and tags; and soon discovered juvenile sharks were frequenting Great South Bay.
The most interesting aspect to me is that the little sharks are not born in local waters, but migrate many miles. Sand tigers are born in southern waters around the Carolinas and travel north to nursery sites during their maturing years. According to Jon Dohlin, vice president and director of the New York Aquarium in an article from the Epoch Times, scientists are not sure why the juvenile sharks use Great South Bay as a nursery. Perhaps due to the estuary being so close to heavy boat traffic, it could be scaring away bigger fish.
Juvenile sand tiger sharks range in size from 9 inches to 4 feet and generally remain in a nursery for 3 to 4 years until they reach between 8 to 10 feet. As adults, the sharks will continue their migratory lifestyle swimming in the surf zone and shallow bays to the continental shelf from Cape Cod to Delaware Bay during the summer, swimming southward for the winter. Sand tiger sharks are normally bottom dwelling creatures that eat crabs, lobsters, eels, bluefish, herring, and other fish.
Author Jose I. Castro writes in The Sharks of North American Waters that sand tiger sharks measure about 39 inches when they are born. In Florida, the birth season is usually from November through February. Only about two sand tigers are born from one female every year, even though there are many more fertilized eggs inside the mother’s uterus. This is because young developed sand tigers will feed on less developed eggs before birth inside it’s mother. Even at a very young age, sharks are the real deal when it comes to survival of the fittest.
Don’t get confused by the name. Sand tiger sharks are not really related to tiger sharks. Sand tigers are actually more related to great white sharks. But while adult sand tiger sharks look vicious with numerous needle-like sharp teeth, they actually pose little danger to people. Author Jose Castro suggests the sharks are sluggish, slow moving swimmers. Sand tigers are shy sharks. If a swimmer approaches them too closely the sharks will often just swim away.
People sometimes see sand tiger sharks in shallow bays as they swim to the water’s surface to gulp air, which helps the sharks regulate their buoyancy in the water. Sand tigers will also sometimes just drift in the water to minimize energy needed to avoid sinking.
Due to their timid and sluggish nature, sand tiger sharks have been over-hunted by people for decades for their fins and food. This has led to great population declines worldwide. As a result, sand tiger sharks are a “species of concern” and it’s illegal for commercial or recreational fishermen to keep one caught from the Atlantic coast of the United States.
Good luck sand tigers! May they live long and happy near New York Harbor. I hope they enjoy our neck of the ocean for a very long time. Take away sharks from local waters, and life becomes that much more boring for people, and aquatic biodiversity in our local waters becomes that much more disconnected and degraded.
To view more pictures, video, or stories of wildlife around Sandy Hook Bay, Raritan Bay, and Lower New York Bay, please visit my nature blog, NY Harbor Nature at http://www.nyharbornature.com