THE DAY ALL THE SHARKS DIED

Once upon a time, there was a seaside village whose people lived in harmony with nature.

They made their living from the sea. They caught fish on the reef that protected the village from the full fury of ocean storms. They gathered clams and oysters, mussels and scallops from the bays and coves and inlets. Some they ate themselves. Some they sold to people in other towns and villages, from whom they bought necessities like lightbulbs and clothing and radios and refrigerators and fuel for their boats and cars.

Their biggest business, which employed the most people and brought in the most money, was lobster fishing. Lobstermen owned special boats and had special licenses that permitted them to set a certain number of pots or traps to catch lobsters. The law permitted the fishermen to catch only lobsters that were too big to pass through a special ring, which meant that they were old enough to have bred and had young of their own. Smaller lobsters were put back in the sea to live and grow, as were female lobsters carrying eggs.

Everyone worked together to maintain a healthy, stable population of lobsters, for many people's livelihoods depended on them. First there were the fishermen who caught them, the mates who worked on the boats, and the wholesalers on the docks who bought the lobsters, processed them, and packed them up for shipping. Then there were the truckers who took the lobsters to stores and restaurants up and down the coast. There were the men and women who worked at the restaurants where lobsters were served, the businesses that cleaned the linen used in the restaurants, and the bankers who financed the businesses. On it went, like ripples spreading from the splash of a stone dropped in a pond.

A small colony of sea lions lived on a rocky point of land that joined the breakwater at the mouth of the harbor. In the springtime tourists from other towns would come to the village and have lunch at one of the restaurants on the harbor. They came just for the fun of watching the newborn sea lion pups playing with one another, or learning how to swim and hunt for food, or sunning themselves on the warm rocks.

The villagers did not think much, or worry at all, about the great number and variety of creatures that lived in the sea. The sea and all its living things seemed infinite, indestructible, eternal.

Nor did they worry about the predators that lived in the sea. They knew that sharks patrolled the reef and the deep water beyond. But never—not in living memory or in village lore—had anyone ever been bitten, let alone killed, by a shark.

The villagers had, of course, been taught from birth to respect the sea and the animals in it, so they took sensible precautions. Even on the scorching hot days of summer no one swam at dawn or at dusk, when sharks were known to feed on the reef. At those times, once in a great while, a dorsal fin could be spotted slicing the flat-calm surface of the water in the harbor.

They never swam near fishermen, or wherever bait was in the water. They never swam if they saw fish feeding or birds feeding on fish. No one swam or snorkeled or dove with a fresh cut or an open sore.

Nobody fished for sharks because none of the locals liked shark meat and there wasn't a market for it anywhere nearby. If a fisherman caught a shark by accident, on a line or in a net, he'd let it go. Nobody in the village ever killed anything just for the sake of killing.

One day people noticed a big boat—big enough, in fact, to be considered a ship—lingering not far offshore. Smaller boats were put overboard from the ship, and they cruised up and down the reef.

Village fishermen who had gotten close enough to the ship to read its name couldn't remember it or pronounce it. It was stenciled on the ship's bow and fantail not only in a foreign language but also in an alphabet nobody could decipher.

The one peculiar thing about the ship that fishermen could describe was that on her stern were two very, very big—gigantic, even—spools. Each spool looked like it could hold at least a mile's worth of thick, strong fishing line. And visible in the coils of line were hooks, too many to count.

When the people in the village awoke on the morning of the third day, the ship was gone. Everything seemed to be okay; nothing looked different.

There was no way anyone could know that, over the past two days, their village had been assaulted.

The first sign that something was wrong was discovered by fishermen who went out to the reef. Scattered over the bottom, in the reef and on the sand, they saw the dead bodies of sharks. (Because sharks do not have swim bladders like other fish, when they die they do not float. They sink to the bottom.) They saw that the sharks had not only been killed, they had also been mutilated. Their fins had been slashed off—dorsal fins from their backs, caudal fins from their tails, pectoral fins from their sides— and the sharks had been thrown back into the sea to bleed to death or drown.

The fishermen's first reaction was anger: so this was what the foreign ship had been doing offshore, killing sharks and taking their fins to sell to the people who make shark-fin soup, an expensive delicacy.

Their second reaction was frustration. What could they do about this thievery? They knew the answer: nothing. The ship had come from a foreign land. From experience the villagers knew that their local police and wardens and marshals had no power over foreign vessels.

Their third reaction was resignation. Well, the shark populations will rebound. Sharks from other regions up and down the coast will come here. Nature will stay in balance.

What they didn't know was that there were almost no sharks in other regions up and down the coast. The big ship and the boats it carried had worked the entire coastline. It had taken nearly all the sharks from all the reefs and used the long lines on the huge spools that sat on the stern of the big boat to catch the open-water sharks, the big ones that fed on sea lions.

For the first few weeks, nothing seemed much different. Fish and lobsters were caught and sold, money was earned and money was spent, and life continued as before.

Then fishermen began to notice that they were catching fewer lobsters in the pots. Slowly at first, then more rapidly, the number of lobsters was declining. Often lobster fishermen found in their pots not lobsters but octopuses. They had never paid attention to octopuses before. Now the octopuses seemed to be everywhere.

Within a month or two, the villagers realized that the number of sea lions had increased, too, especially young ones. As the sea lion population grew, the number of fish caught by the village's fishermen declined. In itself, this was no mystery. Sea lions eat fish, so as their numbers increased, they took more and more fish from the sea.

The mystery was, why had the sea lion population exploded?

Soon there were so many sea lions that they outgrew their rocky point and spread back toward the village. Some took up residence on docks, some on boats moored in the harbor. Since sea lions poop wherever they please, boat owners found the decks and cockpits of their boats soiled and stinking.

When the wind blew toward shore, the stink wafted into the village and made dining an unpleasant experience. Restaurants lost customers. Waiters and waitresses were laid off, and some had to move away to find new jobs, leaving houses and apartments vacant.

Lobster catches continued to drop. Most lobster fishermen had borrowed money from banks to pay for their boats. Some had borrowed to pay for their homes as well. Now, with their income so low, they couldn't make the monthly loan payments. Eventually the banks had no choice but to take the lobster boats from the fishermen and try to sell them to someone somewhere else.

Every one of these decisions and actions became a new stone dropped into the pond. Ripples spread, affecting businesses and men and women and their families for miles and miles around.

And always the question lingered: why? What had gone so terribly wrong so terribly fast?

By the time the answer came the following summer, the village was in trouble. The signs were visible to anyone. The words FOR SALE were printed, stenciled, painted, and scribbled, and hung on houses, boats, shops, restaurants, cars in driveways, and lawn mowers on lawns. The streets were silent, the harbor nearly empty. And the vast, uncountable population of sea lions now inhabited every square inch of waterfront property in the village.

All the sea lions were unnaturally lean. Only those strong enough to swim far out to sea and dive very deep to find fish were able to feed themselves. Even they spent so much energy catching food that they could barely keep themselves nourished; they had no extra to feed to their young. Their natural duty was to keep themselves alive so they could breed new litters of pups every year. And so, as nature had programmed them to do, mother sea lions let their pups starve. The bodies of the dead young sea lions rotted on the rocks and washed around in the shallows.

It was a high school student working on a paper who discovered what had hurt the village, and her discovery wasn't even very complicated. It was just a matter of knowing where to look.

The student examined the food chain in the sea when the village had been thriving. At the top were the sharks. Some sharks preyed on the fish on the reef; all sharks preyed on octopuses. Octopuses, in fact, were one of the sharks’ favorite foods. That was one of the things that kept octopuses from overrunning the reef. Octopuses lay thousands and thousands of eggs at one time, because not many usually survive. When the sharks disappeared, the student discovered, the octopus population had boomed out of natural proportion.

Now, one of an octopus's favorite foods is lobster. An octopus will trap a lobster with one or more of its eight powerful arms, squeeze it to death and crack it apart with its arms, and then eat it with its powerful beak. Even small octopuses can catch and eat small lobsters. So when the sea around the village became overpopulated with octopuses, the lobster population suddenly crashed.

Very soon there were no more lobsters for the fishermen to catch.

Normally, other sharks—larger ones, including great whites—preyed upon the sea lion colony. They took the weak, the sick, the malformed, and the vulnerable, leaving only the strong and healthy sea lions to maintain the colony.

When those sharks were killed by the big fishing ship, there were no predators left to control the growth of the sea lion colony. And sharks are not only predators but scavengers as well. So even the dead sea lions were not recycled into the food chain but were left to rot and become host to flies and other carriers of disease.

The most discouraging discovery the student made was that there was a possibility that the village might never recover. No one could know for certain, but there was a chance that the marine food chain had been altered forever.

A year passed, and another, and then, one day, a couple on a sailboat just beyond the reef saw a dark triangular fin slice through the calm water. A few feet behind it, a tall tail fin swished back and forth. It was a shark, a big one, and whereas a few years earlier the couple might have shuddered at the sight of the fins, now they cheered.

Soon other sharks began to visit the reef, and gradually—very gradually—the number of sea lions declined. So did the number of octopuses, and that meant that more lobsters had a chance to survive to adulthood. By the time the high school student had finished college, lobstermen could once again make a living from the waters around the village.

What had saved the village was an idea hatched by some scientists alarmed by the decline in the number of fish in all the oceans of the world. Too many boats with too much modern technology were taking too many fish from the sea too quickly for many species to recover. The idea the scientists had was to locate areas where fish were breeding and spending their first few months of life and to protect them from fishing.

It took them a long time and a lot of arguing and pleading, but eventually they were given permission to create what came to be called Marine Protected Areas in many places around the world.

One of the MPAs was located a few miles offshore, up the coast from the village. As animal populations in the protected area recovered, their eggs and larvae drifted south and began to nourish the reefs and waters near the village.

Some people resisted MPAs. They believed they should be allowed to fish for whatever they wanted wherever and whenever they wanted and with the most effective killing equipment available. They argued that they had to feed their families now, and they couldn't afford to worry about the future.

Millions of others, however—and their numbers grew—recognized that if random, destructive fishing was permitted to continue, someday there would be no oceans. Instead, there could be a catastrophic collapse of marine life, and along with that would surely come a human catastrophe.

They couldn't let that happen.

And neither can we.