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Tuesday, August 11. 2009

Sharks

There’s a picture of a shark as my monitor wallpaper. Usually I like to spruce up the place with photos of questionable morality, but today the shark has my attention.

It’s a reef shark in a menacing posture, its closed mouth in a serious frown, the fins like wings on the sides of a torpedo, a very aerodynamic projectile designed specifically for bait like you — and me, for that matter.

Sharks are a common occurrence for anyone who spends a lot of time in the ocean. In a surfing video a few years back, a cameraman perched on a longboard caught the telltale, striped figure of a tiger shark lazily swimming beneath the dangling legs of everyone in the water. The surfers understandably reacted with shocked surprise. And then they continued to surf.

It’s been years since I’ve encountered any type of shark, let alone one that could mistake me for a snack, or worse, a rival in the food chain, but every time I don that mask, snorkel and fins the thought crosses my mind, “there are blue sharks just a half mile away.”

Blue sharks eat fish, so people aren’t in their menu, but what they do react to is the notion that humans in the water, their particular swath of ocean, are rivals for the bountiful food fish.

At this stage in life I’m not paddling out past the kelp beds anymore so it’s not likely I’ll run into one, at least not an adult, but we all know what adolescents are like. We’re all such rebels at that age.

If you fish off the Crystal Pier in Pacific Beach there’s a good chance you’ll catch a young blue shark, since they stay close to the shoreline for the smaller food. They will usually be three feet or shorter, hardly menacing, but they have fully developed mouths and teeth and the careless angler could easily lose a finger.

But, as the old axiom goes, shit happens.

Last year a great white shark off Encinitas bit a man swimming with triathletes in training. The shark only bit once, but the man died anyway, the bite being so catastrophic. That’s what scares most people about sharks: you never know when, where or why. You can sort of guess the dynamics of that attack; the man, in his 60’s, was probably lagging behind the main group of swimmers, a signal to great whites that this particular “seal” would be the easiest kill.

Great whites eat seals, which are abundant up and down the Pacific Coast and they tend to prey on isolated animals, or the slower ones lagging behind.

Right now the fairly harmless leopard sharks are congregating at the south end of La Jolla Shores and anyone can wade into three feet of water and be surrounded by hundreds of the fish, most of them being three-to-five feet long. There hasn’t been an attack by a leopard shark in 52 years, but if you trouble one sufficiently, it will fight back.

Sharks are a metaphor, for lawyers, great pool shooters and poker players. Virtually any profession that has what people consider insatiable predators, sharks get the call. Which is too bad because they don’t deserve that reputation.

My scariest encounter with a shark took place in the late 1970’s while scuba diving off the coast of Okinawa, Japan. The shark, don’t really know which species, just lazily swam past and over us as if we were just a part of the reef. The movie Jaws was still fresh in our minds so the moment became such a frightening experience I nearly bit my regulator mouthpiece in two.

Large sharks — all sharks — perform valuable roles in the ecosystem and losing the top predators has severe consequences.

Sharks are being hunted to near extinction. Asian cultures kill them just for the fins and sport fisherman consider them vermin or at best, worthy prey for their fishing charters. Over 100 million sharks are killed every year, that vast majority for the fins. Think of that. The population of the United States is just over 300 million. Because of their reputation as being free, wide-ranging animals many people believe sharks couldn’t possibly face extinction.

In reality, the shark population has decreased by 90% around the world and close to 99% on the U.S. Eastern Seaboard, all due to over fishing. Currently there are 136 shark species on the endangered list. The effect of losing the ocean’s top predators can be devastating to everyone.

One of the prey fish for most North Atlantic sharks is the cownose ray. In 2000, after the shark populations had been severely depleted, the population of cownose rays exploded and they in turn feasted on the bay scallops along the North Carolina coast to such an extent, the scallops almost became extinct and fishing for the mollusks was stopped.

In an article published in Science Daily, marine biologist and shark expert Julia Baum of the UCSD Scripps Oceanography Institute said, “Large sharks have been functionally eliminated from the East Coast of the U.S., meaning that they can no longer perform their ecosystem role as top predators.”

Functionally eliminated. Wow. And yet people still insist on fishing for them. Just as bad, people fishing for tuna or swordfish will catch sharks as well and all of those animals die as a result. You see there’s no easy way to extract a hook from a live shark.

It would be nice to believe laws like the Shark Finning Act of 2000 would at least slow down the slaughter, but it hasn’t. Currently awaiting a vote in the U.S. Senate is bill S850, which would require all sharks caught to be landed with their fins intact. This would end the horrific practice of removing the fins while the shark is alive and in the water, at least in U.S. territorial waters.

The ocean is a wonderful place, sometimes dangerous and occasionally deadly, but it’s a place many of us consider part of our home. The loss of such magnificent creatures will be a terrible tragedy, as the extinction of any species would be so we would like to do our part to preserve and protect all of the ocean’s creatures, especially its top predators.

As foolish as it sounds, I’d like to encounter one of those predators again, if only to see if I can actually bite through a regulator mouthpiece.

Posted by Tim Forkes in Science at 08:01 | Comments (0) | Trackbacks (0)

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