Posts Tagged ‘great white’

Great white and Trey Snow by Thomas Peschak. 

Now that we’ve stirred mild worries in you with entries about a Bald Eagle attack hoax and the surprising (and real) presence of wild sharks of New York City (May 23), let’s go for broke and combine the two themes: shark attacks!


To be honest, this is more of a personal concern. From August 13 through August 27, I will kayak a 300-mile “Memory Paddle” circumnavigation of Long Island to raise funds for the Long Island Alzheimer’s Foundation. I’m budgeting a little time to loop wide at Montauk, in hopes of seeing some “charismatic megafauna” in our local waters. Marine biologist Arthur Kopelman, president of the Coastal Research and Education Society of Long Island, provided the tip that in August there’s a chance of a paddling encounter with sea turtles, pilot whales, dolphins, and…Great White sharks. While I’m a little astonished and disoriented by the idea that I’ll be 40 on August 20, I would still like to live to mark the day. Not that I can complain too much about my upcoming challenge – CRESLI offers viewing tours from the safety of a chartered motor vessel.






Lucky for me, National Geographic Adventure has kindly produced a series of Survival Guide videos, including one for shark attacks. In short, “go for the eyes.” I suppose it will be playing in an endless loop in my mind from, say, August 18 through August 21.


WikiHow goes a little further, offering the paradoxical advice that one should clutching onto his or her shark attacker to avoid chunks of flesh being thrashed off. The user-generated service also advises against screaming, unless you’re sure that it’s about to make you its next meal. Scream, check. Hug shark, check. 


Actually, I will also rig my break-apart paddle to have a sizable blade in the middle or paddle throat base, for easy and quick conversion into a spear. A POD (Protective Oceanic Device) to magnetically irritate the prey-sensing ampullae of Lorenzini of a Great White seems like a bit of overkill (or overpleasedon’tkillme).


It seems most Great White attacks are really the predator’s investigations and errors. When we’re swimming we are a novelty, and so the bites are often the shark’s means of testing our taste, or perhaps any unexpected defense response. The human body lacks the nutrient and fat content of a seal, which is typical prey, so there’s a good chance that a Great White will leave after a nibble. Losing a limb, or part of one, could end in death from blood loss, regardless of the shark’s disappointment.


That optimistic assessment is disputed by some researchers. Marine biologist John McCosker has long noted that the relatively low human fatality rate could be due to our frequent escapes after the first bite. Solo divers fair less well than those who use the “buddy system” of mutual aid.


When in a kayak or on a surf board, we humans exhibit a silhouette that’s very similar to a seal’s. One typical method of attack is to lunge from below, darting inward from a seal’s ventral blind spot. In moments, as recounted in Susan Casey’s book The Devil’s Teeth, the seal is decapitated. In a not-quite-worst-case scenario, a surfer or kayaker can send a Great White home with a mouth full of plastic or fiberglass but be left bobbing in the big blue.


A Great White that senses there’s something odd about the kayak or surfboard form has another means of assessing his potential meal. The species has an usual ability to “spy hop,” that is to look around above the water’s surface. In the photo above, taken in South Africa by Thomas Peschak of Trey Snow (both marine biologists), a Great White is peacefully tailing a marine biologist for a little while out of simple curiosity. One factor in the biologist’s favor might be that Great Whites are notably less aggressive during mating season, and feed much less. Yes, it’s “make love, not Jaws” though Nurse Sharks seem to go in for a bit of rough love.


Now if only I could persuade them to get amorous in August…Would Ravel’s Bolero carry well underwater?


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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. 




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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