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Posts Tagged ‘wildlife conservation society’

Survivor. Photo by Barry Masterson of Kayak Staten Island.

Sharp-eyed Nature Calendar reader Christopher Johnson spotted this seal casually sunning its shark bite wound on rocks near Swinburne Island, in a gallery published at SILive.com (Staten Island Advance, photo by Barry Masterson, co-founder of Kayak Staten Island).

The question is whether this bite occurred in local waters or if the seal is healing up from an attack out east. Breathe a little easy, for now, says Paul Sieswerda, a shark expert and seal watching guide (and fellow Frisian). Paul has kindly written about sharks for Nature Calendar before, and was profiled in The New Yorker for his seal trips. I got to know him when I broke the story of seals returning to New York Harbor a decade earlier in the New York Times. That discovery was made by fellow kayakers (I joined for the confirming trip), who have now gotten familiar with porpoises.

It seems inevitable that larger sharks will return to our waters as the estuary grows cleaner and more bountiful. Prospects for that are good, if unnerving, with the Wildlife Conservation Society’s New York Seascape Initiative fostering the process. Last summer a NYC beach was closed in the Rockaways after a thresher shark sighting, but sadly the specimen was found dead the next day. A series of attacks in New Jersey became the stuff of legend nearly a century ago. Several sources report large sharks being caught off of lower Manhattan before the 20th century, perhaps attracted by rotting meat scraps tossed into the Hudson River. It also seems the Narrows were then, as now, a hot spot for finding larger creatures. A fun exploration of this topic by Tom Vanderbilt was published in the New York Times a few years ago, bearing this gripping image from the New York Historical Society.

Chaos in the Narrows (circa 1880). Collection of the New York Historical Society.

If you see a shark, please report it to the Wildlife Conservation Society’s New York Seascape Initiative. If you see a marine mammal or turtle, even in good health, please report it to the Riverhead Foundation. If you have the urge to get out there among the big fish, please volunteer at a community boathouse on the NYC Water Trail.

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Lightning strike in NYC. Photo by Sara Scovronick. 

 

By Sara Scovronick

I live I high up in an apartment on 8th Avenue in Chelsea with a balcony that faces east over the city; perfect for watching thunderstorms. The thunderstorm that has brought a bit of relief from the recent heat, came in strong and moved out fast last night, with the lightning visible to me first in the southwest and then seeming to move eastward around the island, finally disappearing uptown.  A hard rain fell just briefly on Manhattan in the middle of the storm, miring the clarity of the lightning and muffling the thunderclaps.

 

I’ve read that lightning strikes the Empire State Building around 100 times a year. It is a wonder that any structure can withstand being hit repeatedly with bolts that are temperatures hotter than the surface of the sun. That said, it has become clear to me over the years of watching thunderstorms rage around the city, that lightning does not always strike the tallest object in an area, in this case the Empire State Building, or even the top of the tallest object. How I made it so many years believing this myth I don’t know. Furthermore, lightning doesn’t always travel from cloud to ground, but often occurs inside a cloud or arcs from one cloud to another.

 

 Lightning over Manhattan. Photo by Sara Scrovronick.

 

I love being in the middle of electrical storms. All those shock waves and charges flying around me bring an energy and excitement that is unique and humbling. In this big city, the electrical storms are just about all that can dim the bright lights, even if only for a second.

 

(Sara Scovronick, who also took the photos, is Program Coordinator for the Center for Environmental Research and Conservation. CERC is a scientific consortium including  Columbia University, the American Museum of Natural History, the New York Botanical Garden, Wildlife Conservation Society, and Wildlife Trust. It is centered at Columbia University’s Earth Institute.)

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Sand tiger shark. Photo by J.L. Maher/WCS

 

 

Editor’s note: Yes, there are sharks swimming wild in New York City’s open waters! It took tremendous discipline to hold back this fantabulous Nature Community item by Paul Sieswerda, animal curator of the New York Aquarium (and a rare fellow Frisian New Yorker). But now you have it, for the first weekend of NYC’s public beach swimming season!

 

One sad note is that in the time between his writing and today, the aquarium’s longest-lived shark passed away. Bertha, a sand tiger shark photographed here by J.L. Maher of the Wildlife Conservation Society, was caught off the coast of Coney Island and lived at the aquarium for 43 years. Her species is so common in the New York Bight that the aquarium has traded young ones for others species from around the world. I had a kayaking encounter with another species of shark near the Narrows a few years back, but that tale will wait for another day.

 

 

“Sharks and the City”

 

By Paul Sieswerda

 

As Curator at a public aquarium, I am often above, in, or under the ocean’s surface and I think that I’m not alone in having brief shivers when the thought of what sea creatures may be eying my activities passes through my mind.  It’s just a flash of trepidation and doesn’t slow me down, but I have to admit to it. 

 

Sharks, of course, are prominent on that list of imagery and probably somewhat realistic in tropical waters. But in New York?  You’re right, that’s crazy. 

 

However…

 

The Chamber of Commerce may not like to publicize it, but the waters around New York are full of sharks.  Fortunately, the species are not man-eaters or dangerous, but sharks are plentiful and varied.  It should be stated however, that one of the most horrific episodes in shark attack history took place very close by.  In 1916, four fatal attacks took place along the New Jersey coast within the first twelve days of July, in Beach Haven and  Spring Lake, and miles inland, in Matawan Creek. Another victim was also attacked in Matawan, but survived with the loss of a leg.  That history changed the world’s image of sharks when Peter Benchley popularized the factual story in the book, Jaws.  Of course, the movie seared the fear of shark attacks further into the psyche of a worldwide population. The fishing fleet off Montauk catches enough monster sharks to keep the impression in the back of most New Yorkers’ minds.  However, experience settles those fears for New York swimmers since the chance of a shark attack ranks about in the same neighborhood as the risks as from asteroids.

 

Our native sharks are benign to humans.  Local species are fish eaters like the sand tiger shark or scavengers like the smooth dogfish.  There are sandbar sharks as well cruising off Coney Island beach.  These sharks are happy to hunt fish and leave humans completely alone.   In fact, sand tiger sharks and sand bar sharks rarely take bait from fishermen, so they are not often caught on hook and line.  The dogfish are another story, and many striper fishermen are disappointed to pull in a dogfish instead of a fat striper.

 

Sand tiger shark. Photo by J.L. Maher/WCS

 

Sand tiger shark, Carcharias taurus

The New York Aquarium has a number of sand tiger sharks on display.  One specimen lived in the collection over 40 years.  How long do they live? The shark in the photo, Bertha, was the longest living shark recorded at an aquarium and it was probably a couple of years old when it was captured.  Since then, the Aquarium has supplied itself and other institutions with sand tiger sharks.  Local fishermen catch them in their nets and notify the Aquarium.  Since these sharks are usually small they can be transported fairly easily.  Some have been sent as far away as Japan.  A “pupping”  ground seems to be along the southern coast of Long Island.  Young sand tigers are caught each year incidental to the fishermen’s target species.

 

            First Come, First Served

Sand tigers have a strange method of development. The embryos practice hunting within the mother!  This cannibalism before birth is called oophagy.

 

Eggs are produced in the shark mother’s two uterine tracks, one after another.  As the first egg develops into an embryonic shark, it eats the next developing embryo.  This continues until the birth of the two babies that have grown in each uterus.  They grow strong feeding on their potential siblings.  At birth, the young sand tiger sharks are forty inches (100 cm.) in length, and completely ready to hunt on their own.                                              From : Sharks by P. Sieswerda

 

The adult sand tigers are usually about seven feet in length.  They have two equal sized dorsal fins set at the rear half of the body.  The nose is pointed and often upturned.  The most prominent feature are the teeth that Richard Ellis, author and naturalist, calls the “wickedest-looking teeth in all of sharkdom.” 

 

These teeth, however, indicate that they are fish eaters and not prone to take bites out of large animals (species that do are a real danger to humans). Although they look ferocious, sand tigers have adapted a mouthful of fangs that are designed to effectively grasp slippery fish. Most sharks must continually swim at a speed that gives them lift, but sand tigers are able to keep from sinking by holding a gulp of surface air internally, allowing them to cruise at slow speed and save energy for quick lunges that catch their prey unaware. In aquariums, it was found that sand tigers needed a minimum depth in their tanks, not for any space requirement, but to allow them enough distance to launch themselves above the surface to gulp air.

 

 

Most New Yorkers will not see sand tiger sharks except at the New York Aquarium, but it may be interesting to know that when gazing out from a Brooklyn or Long Island beach, or even sharing the surf, there are sizeable sharks out there playing out their lives, with little threat to people and deserving only the slightest twinge of fear. Knowing the facts is comforting, but I think it’s human to worry a little.

 

Or is it just me? 

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