Shark Man has a Birthday

My nephew, Thomas Bates, an avid follower of this blog, is unusually interested in animals. He likes all kingdoms, all kinds, anything with a heartbeat and eyes, but he is especially fond of the wild animals, and of those, especially the ugly or the fast or the dangerous. I remember in previous years a particular fascination with frogs. His bedroom was hung with frog art, and any frog found in the yard became a closely held companion, at least until supper time. On a catamaran tour of Kauai’s Na Pali coast in 2010, Thomas stayed on the bow longer than any other passenger, and way into the ocean’s growing roughness, because he had earlier seen spinner dolphins shooting out of the water like slick, grey rockets, and below the hulls whole families cavorted in the boat’s wave just beyond arm’s reach. The captain finally required we real him in for fear he’d be washed overboard. Thomas, by this time a prune of a boy and shivering, had a look about him that I recognized. It was the look of enchantment, like being washed overboard into the company of dolphins would have been just fine.

More recently Thomas’s interest, I am told, has turned to sharks. Sharks in the river behind his rural Texas home are few to none–he knows; he has looked–and fewer still swim in the pretty pool of the back yard. So, for purely objective reasons, for the simple pleasure of observing and reporting back to science the strong swimming characteristics typical of the species, Thomas requested a remote-controlled shark for his birthday.

Today Thomas turns eleven.

This morning I was musing about Thomas as I sat in the cockpit looking down into the clear water of yet another Moorea lagoon. Murre and I have moved since our last post, but barely; we’re just outside the eastern arm of Cook’s Bay and a scant two miles by crow from our last spot. The channel behind this reef is deep, the water, inscrutably blue, but to the north the sandy bottom shelves quickly to a shallow plateau of a light, crystalline green. Murre’s anchor is visible from the bow, tossed out onto this plateau of eight foot water, but the boat rides back on her chain to the cliff edge, and from the cockpit I can see into the deep.

It’s just sand, so the reef creatures are few. A pair of angel fish large as dinner plates swim up toward me when I gaze over the side. Large grey rays and the smaller black and speckled eagle rays feed in the shallows. Jacks and spiny cow fish follow them for scraps, and further on and down a school of unicorn fishes jostles. Further still and further down, I see sharks.

The interior of the reef is dominated by Black Tip Reef sharks–the deeper the reef, the bigger they get. I’ve seen them to six feet long just below us this morning, gliding with a slow grace that suggests their reserves of power are infinite. And swimming with them takes some getting use to. Your first few sightings freeze the heart; the flight reflex slams into your head like a freight train; you reach for the bowie-knife strapped to your thigh. It’s not there; you never bought it. You just know you are toast. Then after a time you realize these sharks only show you their backside. They see you first, and they are always fleeing. So, lately, I’ve taken to chasing Black Tip Reef sharks, not for purposes of harassment, but just so I can get a better look.

I wonder if Thomas would like swimming with reef sharks. It’s quite the sport. Polynesian children often chase the smaller of these sharks in the wading pools. If they catch one, they take a ride. I’ve seen photographs of men riding the larger sharks too, a hand around each ventral fin, but here the challenge is not the riding but the capture. In Hawaii shark riding was a time-honored tradition on some islands, and the act granted status to the successful just as bull riding does now.

When Joanna visited Moorea with me, we swam with grey rays and sharks at a famous tourist spot not three miles away. The rays glided right up for their tidbits of fish, allowing all comers to caress their silky, flowing skin. But the sharks kept their distance, patrolling a stretch of blue too deep for us to reach on tippy toe. If we swam too them, they vanished.

Outside the reef, the number and type of sharks increases dramatically. Just outside the pass to Opunohu Bay is a large school of circling Lemon Sharks. To eight feet, this shark appears thuggish and thick. Its teeth stick out at odd angles, and in the right light its skin is perceptibly jaundice. But it too is wary and may retreat if approached, unless you happen to be spear fishing. And here, I am told, Hammerheads can sometimes be found in large schools soaring near the reef wall like great fleshy hawks on a gyre.

And what an amazing fish for a young man to admire. Sharks can smell food sources, like blood, from as much as a quarter-mile away or hear the thrashing of a wounded animal from up to a mile. Proximity allows them to sense an organism’s weak electrical field. They lack the altitude regulating gas bladders of other fishes, and so, in most species, if they are not swimming, they sink. This suits the bottom dwelling sharks, and some can even fan their own gills with water as they rest in the sand or in rock caves, while most sharks must keep a move on or they suffocate. Sharks that hang out in middle levels use oil glands for buoyancy. This means that sharks can rise in the water column much faster than other swimming animals–they can attack from below. This hunting tactic featured prominently in a particularly compelling movie, the name of which escapes me.

Shark skin is rough and can be used as sand paper; the Japanese fasten it to cutting boards for the grating of fresh wasabi root. The roughness is due to embedded “dermal denticles”, essentially tiny teeth, that are aerodynamically grooved and allow the fish to move faster through the water than if its skin were smooth. A shark’s teeth are simply enlarged and modified dermal denticles that grow out of the shark’s mouth skin rather than its jaw cartilage. This strategy allows the teeth to be replaced easily, conveyor-belt fashion from the inside, and as often as every eight days in some species.

Many sharks are live-born. Gestation periods can be as much as twelve months, and if the mother carries more than one pup, the larger of the two will sometimes eat the other while they are still in the womb. All sharks are carnivores, but many engage in experimental eating. The Tiger Shark, for example, likes garbage. “The stomach of a ten foot specimen harpooned in Pearl Harbor in 1931 contained the hind leg of a mule, two bathing suits, a belt buckle, a pint of buttons, two horseshoes, the corner of a wooden soapbox, two small anchors, anchor chain and assorted bolts, nails, and copper fittings.” [1] Whitetip sharks are so strong that they can shove boulder-sized coral out of the way while digging around for octopus. Many have small, tightly defined territories but some travel widely. A Great White tagged off the coast of California in 2000 was tracked by satellite all the way to Hawaii, 2,280 miles away, where it hung out for four months before the sensor died.

One could do worse than be interested in sharks.

Thomas is a talker. Never have I met a young man for whom the first amendment protected more. For him talking is less a right than a physical necessity. Subtract talking from the picture and you might as well subtract Thomas. And so I imagine that Thomas talks to animals, knowing they could talk back if they wanted to or if he could somehow figure out their language. I share this imagining. I wish the wild animals I encounter would allow a closer approach, would offer up some clue to what they’re about without so much chasing. Sometimes the more curious fishes in this reef will swing up,turn and give me the eye, and it is then that I feel again the familiar enchantment. For that moment it seems knowing them is within arms reach.

Which is to say, I wish Shark Man a happy birthday.  I laud his interest in the wild kingdom and will be looking for his full report on the natural history of battery operated Carcharhinus Thomasi.

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[1] The quote and shark facts culled from HAWAIIAN REEF FISHES, John P. Hoover, Mutual Publishing, 2008.