On coastlines the world around, the cry, "Shark!" sends swimmers tumbling to shore. Voices take up the chant, and it is carried mile upon mile. The swimmers stand on the warm shoulder of the beach and stare at the water. Later, they may swim again, but not so far out as before. Children invent a game called shark and lunge at each other in the shallows. They will play it for days, and for days it will unsettle their elders.
On the high seas the cry, "Shark!" rouses the off watch, and baited lines are put over the side. If a shark is caught and hoisted aboard, writes Jan de Hartog in A Sailor's Life, "the aft deck turns into a slaughterhouse. The men go berserk in a prehistoric orgy of fury and blood and rip out the animal's stomach to see what is inside.... When the orgy is over, there is a bewildered sense of shame...."
In his fear and hatred of sharks, in his morbid curiosity about them, man tends to be more emotional than reasonable. The danger from sharks at times has been exaggerated; still, their capacity as man-killers is well documented, and has been for some time. Nineteen centuries ago, in his vast Natural History, Pliny the Elder reported shark attacks on Greek sponge divers. Anyone wanting fresher evidence need look no farther back than last spring. On May 7, in San Francisco Bay, a shark seized 18-year-old Albert Kogler. A brave girl rescued Kogler, but he died within three hours from loss of blood. From the ragged wounds on Kogler's body, Dr. W. I. Follett, Curator of Fishes at the California Academy of Sciences, identified the killer as a great white shark armed with saw teeth, like those shown life-size in the jaw that frames these pages.
Five weeks after the attack on Kogler, in La Jolla Cove north of San Diego 33-year-old Robert Pamperin, a Convair engineer, was eaten by a shark. In the last tragic moments Pamperin's diving buddy, Gerald Lehrer, saw only this: silhouetted against a bright bottom 25 feet down was a 20-foot shark, jerking its head from side to side, Pamperin's body protruding from its mouth. In mid-August an Army lieutenant, James Neal, disappeared while skin-diving off Panama City, Florida. A shark is suspect: rescuers looking for the missing lieutenant found only tooth-scarred equipment. In July and August sharks of uncommonly large size were sighted in Buzzards Bay, Long Island Sound and off the Jersey coast. At this time of year northern waters are cold and inhospitable. Most sharks have moved southward. Vacationers, like the sharks, also are headed south to the playgrounds of Florida, the Bahamas, the Caribbean and Mexico. While swimming, skin-diving or fishing in southern waters, these vacationers surely will see sharks, and with the shark attacks of last summer in mind they might justifiably wonder if sharks are invading all the favored watering places of man. Actually, the situation is more the opposite. Sharks have always been around in good numbers. People have not. It is an inescapable and somewhat chilling fact that as an exploding, pleasure-bent population takes to the sea, it is bound to meet more sharks. The skin-diver is particularly vulnerable. There are five million of him now and, professional divers of one kind or another excepted, he pokes farther and stays longer in shark country than anyone ever has by choice.
Compared to all the natural and self-made calamities that befall mankind, shark attacks are indeed rare. Every day of his life, a man is safer in water with sharks than in a motorcar on the roaring road, but that fact is no help at all to the man who suddenly sees a large fin break the water near him. Man has learned to live with the dangers of fire, flood and automobiles; he still has a profound aversion to being eaten.
Since 1900 there have been at least 70 authenticated shark attacks in continental U.S. waters, and another 20 attacks around the Hawaiian Islands. These totals are incomplete and always will be. There probably have been other attacks not witnessed—notably attacks on persons lost at sea. Dr. George Llano, a shark authority now at the National Academy of Sciences in Washington, has stated the problem with cold simplicity: "When sharks are successful," he wrote in the survival manual, Airmen Against the Sea, "they leave no evidence."
Of the shark, it can be fairly said, to know him is to love him less. Though unloved (and perhaps unlovable), the shark is among evolution's most extraordinary creatures, a living relic of prehistory, simple and set in its ways, but at the same time as unpredictable as the 20th century. The shark most often moves slowly, but he can move fast. He often plays the coward, yet he can be bold. At times he seems an oafish blunderer, but actually the shark is an accomplished hunter, mindlessly lethal.
While man is barely a million years old, the shark has been around since the early Devonian period, 350 million years ago, and seems to have survived the ceaseless and brutal turmoil for food and living space by the simple process of not evolving much. The most obvious change in sharks has been in size. Fossil teeth indicate that in Eocene times there were carnivorous sharks 100 feet long. Why these behemoths slipped into oblivion, no one knows. In any case they are gone and unlamented.
Contemporary sharks are only a small part of the great, diverse class of fishes. Of the more than 30,000 known species of fish, only 300 or 400 are properly called sharks—the exact number of shark species cannot yet be fixed because the ichthyologists sorting through the shark order still do not agree which are distinct species and which are merely variants. Whatever their number, all sharks are lumped in a single zoological order, the Selachii, a word generally credited to Aristotle, although it actually pops up earlier as a word within a word in the writings of Aristophanes. Aristophanes wrote the recipe for a fish-and-meat pie as a single, tongue-tangling word that must surely be the longest word in literature. "Legadotemachoselachogaleocanio—" it begins, and then runs on for 149 additional letters.
The so-called modern sharks ("modern" is a word of considerable breadth, since it includes the Port Jackson shark of Australia, which has been around for 50 million years) are a richly varied assemblage. Most species favor the tropics and subtropics, ranging into colder latitudes only with the warming sun. Yet there is a resident shark in almost every nook and cranny of the oceans, even in arctic waters where the Greenland shark, appropriately named Somniosus microcephalus, lies drowsily under the ice floes until hunger sends it scrounging for halibut.
Though commonly thought of as marine animals, sharks roam a thousand miles up the Ganges, Tigris and Zambesi rivers, and one species, Carcharhinus nicaraguensis, lives in Lake Nicaragua. Opinion is divided on whether nicaraguensis is landlocked or has access to the sea in the San Juan River. In any case, the Nicaraguans wish it would go away, for it is a known man-killer.
In size, sharks range from Euprotomicrus bispinatus, which matures when less than a foot long, to Rhincodon typus, the whale shark, that grows to a length of 45 feet. The whale shark has more than 4,000 teeth, all small and apparently of little use, and, like the basking shark that runs almost as large, lives by straining from the water clouds of plankton and other nourishing minutiae. These two large species of shark are monumentally phlegmatic. Now and then a ship rams one, and a 40-foot whale shark off Baja California put up no fuss when it was boarded by a party of divers led by Conrad Limbaugh of the Scripps Institution of Oceanography.
"By swimming hard," Limbaugh relates, "our group of four with swim fins could keep up with the shark. We clambered on the shark, looking it over closely, even looking in its mouth. It showed no sign of concern except when we bothered its face. Then it slowly dived out of sight. But it would return to the surface, and we would climb aboard again."
Most fish belong to a superorder, the Teleostei, commonly known as the order of bony fishes. The sharks do not have a true bone in their bodies. The internal frame of a shark, though fortified with calcium in some species, is essentially cartilage, and that is why whole fossil sharks are hard to come by. Ancient sharks moldered away, leaving little more than their enamel-coated teeth on the stone pages of the past.
The females of most bony-fish species lay a vast number of eggs, which the males fertilize somewhat haphazardly with milt. Thousands of eggs go unfertilized, thousands more are destroyed by natural calamities and eaten by predators. Thus the codfish may lay 9 million eggs to perpetuate its kind. Sharks, though definitely of a more primitive order than the bony fishes, breed by copulation. The females of some shark species lay fertilized eggs, but most bear live young. Some species may have only two or three young in a litter; the most prolific rarely litter more than a hundred. Sharks do not feed large families to compete in the complicated life of the sea, for puppy sharks enter the ocean world fully formed, devilish miniatures ready to fend and forage for themselves. Lacking the air bladder that helps most bony fishes hold their place in the vertical world of water, from the day he is born the shark swims or he sinks.
Ichthyologists are in fair agreement that shark eyesight is of a poor sort—shark eyes are sensitive enough for the dim goings-on in the depths, but probably do not focus well at a distance. At Marineland, Fla. a diver in the exhibition tank once shoved aside an advancing shark. The shark swam head-on into a pile of rock and bit it.
By human standards, the shark's sense of hearing is adequate in the sonic range, and good also at lower frequencies. In their hunt for food, sharks respond to low-frequency vibrations such as a faltering fish or a swimmer sends out, but more than anything, it has been by following his supersensitive nose that the shark has come so far along the road to survival. The brain of a typical 8-foot shark is about 6 inches long, resembling, when viewed from above, a slingshot with forks extending toward the nostrils. A small, posterior part of the brain is given over to sight, hearing and to whatever dull sort of thinking the shark does. Most of the brain—the anterior part of the handle and the forks—is devoted to the phenomenally acute sense of smell. Fifty years ago, Dr. George Parker of Harvard determined that dog sharks use their noses much as plane pilots today use radio to fly on a beam. In the shark's seemingly aimless and stupid wandering to and fro, there is actually method. If a shark veers too far to the left, away from an unseen source of food, the scent comes stronger to the right nostril, and the shark turns back to the right. If he then turns too far right, the left nostril gets the stronger signal, and the shark corrects his course again. When Dr. Parker blocked one nostril of an experimental shark, the shark swam in circles, obeying the signals of the one good nostril. If the left nostril were blocked the shark swam clockwise; if the right were blocked, counterclockwise. On windless days, when the sea is slick and the current slight, fishermen see sharks picking up a scent more than a quarter mile away. The rich juices of a single gutted fish are barely visible 10 feet from the boat; the dilute scent surely is very faint 100 feet beyond, yet the shark crossing the trail far astern will suddenly turn and zigzag errorlessly up the trail to the source.
The mouth of a hunter shark is a graveyard of little white tombstones, row upon row of them. In the first row of each jaw, the hunter shark has about 25 erect, mature teeth. Behind are rows of younger teeth, which in some species, like the tiger shark, lie in perfect symmetry and in others, like the mako and the great white shark, tilt this way and that. The serrated teeth of the white shark are roughly triangular, those of the mako and sand shark are slim, rakelike and sharp as an awl. Some species, like the dusky shark, carry fairly broad teeth in the upper jaw for shearing and more pointed teeth below for holding. Whatever size and sort his teeth, no shark ever lacks for them. Shark teeth are not set firmly. Some age and fall out. Some are torn out on hunting sorties. But there is always another tooth, another row of teeth, like redcoats in a British square, ready to move forward and fill the gap.
The shark is virtually covered with teeth. His whole body is plated with close-set denticles, minuscule "skin teeth" which, like his true teeth, sprout from the epidermal layer and are coated with dentine or enamel. This leads to the moot question of whether the shark's teeth are skin or his skin teeth. Regardless, the skin is tough. Shagreen, oldtime cabinet makers named it, and it made fine sandpaper. It can turn a skin-diver's spear and burr a sharp knife. Some of the bloody damage to human victims, the post-mortem experts now know, is inflicted by the shark's fine-cutting skin teeth.
The sharks are mighty hunters, but not murderers. None of them has brains enough for cunning or treachery. They live by instinct and conditioned reflex; their favored quarry is the creature in distress, the straggler, the hurt and the unfit, whether it be fish or fowl, man or dog. Off the Kenya coast last November a thirst-crazed elephant stampeded into the ocean and was done in by sharks. The shark preys on the living but takes also the dead and the long-dead and the rubbish of the sea, scavenging at times with the voracity of a deranged goat, eating wood and rocks, bottles, paper cups and tin cans. The stomach of a shark caught in the Adriatic yielded three overcoats, a raincoat and an automobile license plate (but no human remains). In 1799, when the U.S. and Britain were involved in a maritime spat, the American brig Nancy was hauled into Port Royal, Jamaica to be condemned in court as a war prize. The American captain had thrown his papers overboard and in court claimed neutrality based on false papers. The prosecution produced the real papers, taken from the stomach of a tiger shark caught south of Santo Domingo.
Twenty-five years ago, in the waters off Sydney, Australia, a 14-foot tiger shark ate its way into an even more spectacular court case. In the spring of 1935 a fisherman who found the big tiger tangled in his set lines gave his captive to Sydney's Coogee Aquarium. Eight days later the shark languished and regurgitated a whole human arm. In the opinion of a surgical expert, Dr. V. M. Coppleson, who happens also to be Australia's foremost authority on shark attacks, the arm had been cut off too cleanly to be the work of the tiger shark. There was a short length of rope tied to the arm. The forearm bore a tattoo of two boxers facing off, a sure clue that the arm belonged to 45-year-old James Smith, a billiard maker and onetime amateur boxer whom the police suspected had been murdered by partners in crime. One of Smith's cronies recently had bought a mattress (conceivably to replace one bloodied in Smith's murder) and also a tin trunk (large enough to accommodate most of a body). When the shark gruesomely delivered up Smith's arm, the crown had a clincher for its case. But defense counsel reached far back into history to fetch the crown a terrific counterblow. By an ancient British law, de officio coronatoris of the year 1276, a single arm is not enough to establish corpus delicti. The big tiger shark was cut open, but its stomach yielded nothing more. The case was dropped. The rest of James Smith is still missing.
The earliest records of man's difficulties with sharks are sketchy. Ancient mariners—and ancient historians—called large fishes "monsters" and let it go at that. Thus when Herodotus wrote that sea monsters attacked sailors of the foundering Persian fleet off the Thessalian coast in 492 B.C., it is a fair assumption, but only an assumption, that the attackers were sharks.
Since Aristotle's day there has been some learning for the sake of learning, but most of what is known about sharks has been learned of necessity. It was not until the era of exploration, when so-called civilized men sailed all the warm seas, that the shark came to be well known, fairly well misunderstood and totally disliked. In 1569, Captain John Hawkins, a freebooter specializing in the rascally business of pirating slaves, exhibited a large shark in London. It is believed Hawkins' men originated the word "sharks" from the German Schurke, meaning villain.
Early sailors, finding human remains in many species of large sharks, hung the charge of man-killer on the whole lot. Because they eat the dead, sharks take many bum raps. The worst part many sharks ever play is that of a garbage collector cleaning up some sorry mess created by man. However, from attacks reliably documented, there are known to be at least a dozen species of man-killers. By their makeup and behavior, several dozen other species are strongly suspect. Unquestionably the No. 1 killer is the great white shark, Carcharodon carcharias, a strong, fast and intemperate fish that at times attacks small boats seemingly out of pure whimsy. The great white is found almost everywhere but, as sharks go, it is not abundant—and that is a blessing. A white shark matures at about 14 feet and 1,500 pounds. The largest gamefish ever caught on rod and reel was a 16-foot, 10-inch, 2,664-pound white shark taken by Alf Dean in Denial Bay, Australia—a record not likely to stand forever, for white sharks are known to run over 20 feet.
The Pacific mako, I surus glaucus, a near relation of the great white, is a killer, but an infrequent one that rarely invades the shallows used by man. At least one species of the hammerhead family, probably the common species Sphyrna zygaena, has attacked men occasionally. The Carcharhinidae, the largest family of sharks, contains a number of bad actors. The worst of the carcharhinid family is the tiger, Galeocerdo cuvier, which, because of its abundance over a vast range, actually causes more trouble than the great white shark. The tiger feeds by day or night in the shallows and out to 200 fathoms, just about everywhere in temperate and tropic waters. In the Atlantic the lemon shark, Negaprion brevirostris, like the tiger, is often found inshore, in shallow guts and estuaries, uncomfortably close to boating and bathing areas. In the carcharhinid family, one genus, Carcharhinus, includes at the very least three certified killers. One of these is the fresh-water shark, nicaraguensis. Another, gangeticus, ranges the Indian Ocean and far up into the sweet water of rivers. The white-tip shark, longimanus, of the same genus is a particular worry to castaways on the open waters. The white-tip rarely visits inside the 100-fathom curve, but in the tropics it pretty much has the open ocean to itself, investigating, bumping every floating object and taking whatever is reasonably digestible. "White-tip sharks are not easily driven off," reports Stewart Springer, a veteran sharker now with the U.S. Fish and Wildlife Service. "In fact, I do not know anything except a beaker of Formalin poured down the gullet that elicits a very strong reaction. They continue a slow and persistent attack despite nonmortal bullet holes." Very probably the genus Carcharhinus includes other killers—possibly the bay shark, of the Pacific coast, and the dusky and cub sharks of the Caribbean and U.S. East Coast. The various species of the genus look much alike, and in the murk and swirl of an attack not even an expert can be sure of the exact species.
Of all the popular coastlines, none is so grievously plagued by large tiger and white sharks as eastern Australia. As if these worldly killers were not enough, in Australia other species of the carcharhinid family, commonly called whaler sharks, add to the toll. The beautiful Australian coast seems to bring out the worst in sharks. For example, the Australian sand shark, Carchariasarenarius, commonly known as the grey nurse, has been charged with a number of crimes. In contrast, the grey nurse's near twin, the American sand shark, Carcharias taurus, prowls off popular Long Island beaches armed with the same rakelike teeth, but has never been known to take the fatted leg of man.
In their effort to cope with sharks men have tried a wild variety of devices and ruses. Some Japanese divers wear red sashes to dissuade attackers, and Ceylonese divers still put more faith than they should in shark charms. California tuna fishermen capitalize on the sharks' interest in bright objects by punching holes in cans of Drano and dropping them overboard. The lye and magnesium in Drano, combining with digestive juices, play hob with the shark's insides, which ordinarily seem as indestructible as an acid vat. Eighteenth-century Mediterranean sailors thought they could forestall attacks by feeding the sharks loaves of bread. When that did not work, a man was hung over the side to make faces at the shark. Such futile antics point up the biggest flaw in early attempts to thwart sharks: nobody knew enough about the creatures or how they behaved. Casting bread on sharky waters happens to be a waste of time, and when sharks are in a feeding frenzy, the man who hangs too close to the surface to grimace, may lose his head—face, grimace and all.
By the end of the era of exploration the sea world was pretty well known. By the 19th century there were better sailors, much better ships, relatively less contact with sharks and thus less need to know them. The world's navies were doing their hardest fighting in cooler waters, where castaways ran far greater risk of death from exposure than from sharks. The pendulum, in effect, swung back. There were fewer lurid accounts of attacks and an increasing number of debunkers—both men of knowledge and men with big mouths—pooh-poohing the threat of sharks.
Near the close of the last century, Hermann Oelrichs, heir to the North German Lloyd shipping fortune and a sea lover, offered a $500 reward for sure evidence of a shark attack north of Cape Hatteras. Oelrichs' offer presumably expired with his death in 1906. The evidence came too late, but when it came, Oelrichs' $500 would scarcely have covered the funeral expenses. On July 2, 1916, a shark killed Charles Vansant in shoulder-deep water off Beach Haven, New Jersey. Four days later, a shark killed Charles Bruder at Spring Lake 35 miles north. And, despite assurances of several authorities that there was little to fear, six days later in Matawan Creek, inside the sweeping arm of Sandy Hook, a shark killed 10-year-old Lester Stilwell and his unsuccessful rescuer, Stanley Fisher, and so badly mauled 12-year-old John Dunn that his left leg had to come off. The five attacks probably were the work of a single raider, an immature white shark a scant 9 feet long. The 9-foot killer was caught two days later near the sites of the last three attacks; in its stomach a taxidermist found human bones implicating it in one of the two earlier attacks farther south.
The Australians have been real believers in the shark menace since the turn of this century, when they cast off Victorian prudery and headed for the water en masse. In his book Shark Attack, published last year, Dr. Coppleson of Sydney lists 147 attacks in Australian waters over the past 40 years. Since 1937 many of the popular Australian beaches have been protected by meshing. In the Australian system a pair of 500-foot nets are set off the beach at night, then picked up in the morning, and the snared sharks removed. This mobile type of meshing has virtually canceled out shark attacks on popular beaches. South African beaches in the Durban area adopted a system of permanent meshing, successful so long as the netting is maintained. The trouble with either system is the expense: Dr. Coppleson estimates the cost of each meshed shark at about $32. The obvious alternative to such mass protection is some sort of portable, personal shark deterrent.
When World War II spread across the tropics, a repellent became a necessity, for morale reasons if for no other. There was no concrete suggestion of a repellent in shark literature, nor any facilities adequate for testing large sharks under controlled conditions. For the initial tests in the summer of 1942, Stewart Springer, who then had considerable experience as an adviser to commercial sharkers, used smooth dogfish. Springer and his colleagues at Woods Hole Oceanographic Institution found the durability of the small dogfish astonishing. They fed undisturbed by supersonic sound. They ate bait soaked in sodium cyanide and swam through clouds of rotenone. Usually the dogfish died, but not soon enough—large sharks affected similarly would have had ample time to maul a man. In all, 78 substances were tried, and the most promising sprouted from an educated guess. From his commercial fishery experience, Springer knew that, for all their catholic tastes, sharks do not like decomposing shark flesh. From this lead, a repellent of copper acetate was developed which, when first tested against large sharks in Ecuadorean waters, seemed promising.
The Ecuadorean test indicated that a lone shark poking around for food could be deterred, but it did not show what effect the repellent would have on a pack of sharks, or even on a lone shark under different conditions. No one, of all the fishermen, divers, sailors and scientists that have looked upon them, can predict how sharks will attack. A shark may circle an object of interest for long minutes. He may nudge it repeatedly but never mouth it. He may swim leisurely in and leisurely nip. He may charge and bite. The active feeding of another shark can send him into a frenzy of feeding, and he in turn will infect other sharks until the water boils and the sharks will attack anything. At times the slightest thump on the nose will make a shark retreat, at other times, though so badly gored that his own entrails are in the water, the shark keeps on feeding.
Unhappily, when the copper acetate was first tried on packs of sharks, it had little effect. Off Florida and Mississippi, copper acetate was put overboard with trash fish from shrimp boats. The trailing sharks bit as enthusiastically as ever. When a bushel of wood chips was dumped over, the sharks ate them too. A nigrosine dye was subsequently added to the repellent, conceivably to serve like a squid's inky ejections to repel attackers. The nigrosine dye improved the repellent, but still the most that can be said for this packaged "Shark Chaser" is that it repels some sharks under average conditions. All that can be said for it when a mob of sharks is in a feeding frenzy is that it probably does not attract more sharks. Four years ago, the Australian-American Bob Dyer, familiar in Australia as a television performer and famous the world over as a sharker, was asked by U.S. and Australian naval men to test Shark Chaser. On the waters of Cape Moreton, Queensland, bloodied by the kills of whaling ships, Dyer often has 10 or 20 sharks mobbing his boat, rising out of the water to snatch gobbets of chum hanging over the side. In Dyer's repellent tests sometimes the sharks ignored the packets. Sometimes they ate them.
Two years ago the Navy set out to do better. With Navy support, the American Institute of Biological Sciences set up the Shark Research Panel to serve as clearinghouse for shark studies the world over. With no war on their necks, the panel—consisting of Dr. Perry Gilbert, Professor of Zoology of Cornell; Dr. Leonard P. Schultz, Curator of the National Museum's Division of Fishes; and the veteran Stewart Springer—can afford to face the job properly, studying previous attacks, investigating new cases and finding out more about the makeup and ways of the worst killers. From work Dr. Gilbert has already done—much of it at the Lerner Marine Laboratory in Bimini, Bahamas—he can confirm that large sharks, in the manner of the small dogfish tested by Parker 50 years ago, use their noses excellently as direction-finders—detecting odors as dilute as one part in 50 million. Gilbert's work further indicates that shark eyes may not focus at a distance, but nonetheless serve the shark well. However blurred he may see it, the shark can pick up distant moving objects even in dim light. It is as if the retina were capable of increasing the contrast, separating moving objects from the dull background of the depths, spotlighting the swimmer in murky water.
In the data already gathered by the shark panel, and in the experiences of scientists and sportsmen in the last two decades, the water-lover today already has some good, general advice. A wise swimmer knows that any new stretch of water should be investigated carefully. He knows too that in bad areas the shallows can be more dangerous than the middle of the Gulf Stream, for sharks have killed people in water barely two feet deep. The masked skin-diver can be more venturesome than a swimmer in clear water, but he has little advantage, as Gilbert's recent work confirms, in murky water. Water containing garbage is chancy, for it makes sharks more competitive and witlessly bold. Water with a trace of blood can be dangerous (blood of a wounded whale may have attracted the large shark that ate Robert Pamperin in La Jolla Cove last year). There are still spearfishermen who foolishly carry their fish on a string rather than boating them immediately. Considering that a shark can pick up the barest scent, even having a taint of fish on the hands may bring a shark.
Because the bad actors of the carcharhinid family fairly well typify most common large sharks in appearance, the smart diver does not bank on identification but presumes any shark big enough is also bad enough. The smart diver who sees one shark starts looking around, for without question, the diver's odds drop as the number of sharks increases. Because he is not pinned to the water surface, the scuba diver has some advantage over the swimmer and snorkeler, but the scuba is no shield—sharks have attacked as savagely on the bottom as on the surface. Inexperienced spearfishermen are prone to the error that the mush-mouthed, sluggardly species of sharks—the Atlantic nurse shark, the carpet sharks and wobbegong—are safe marks. Not even these sluggards like to be prodded and pummeled, and they will bite back.
Over the years, men have found that blowing bubbles, shouting and kicking have sometimes deterred sharks and sometimes have not. Whatever the percentages, once the shark has committed itself to move in, all such protests are worthwhile, for often a shark heading in fast has been turned by a very feeble gesture. The buddy system, though not always effective, as in the tragic case of Pamperin, is still a sound practice. Strangely, there are relatively few cases of a shark bothering a rescuer. In 1952, when a 17-year-old California boy was badly mauled, five men managed to drape him across an inner tube. The shark circled and finally pushed between two rescuers to bite his original victim.
Based on the evidence, there is some safety in numbers. Dr. Coppleson notes in his book that attacks often are made on the one Australian surf rider who missed the wave and was left behind by his companions. For the timid sportsman and the overanxious parent, one bit of advice is worth stating and restating. For anyone taking logical precautions—using familiar swimming areas, investigating all diving areas and always swimming and diving in water free of garbage and slaughter—the shark risk is far less than dozens of others any wholesome man takes in his average pleasures.
The present shark panel is unlikely to come up with any packet of absolute magic. But its research and data should yield better advice and practical devices to help the castaway, fisherman, diver and swimmer. Certainly the shark can be controlled better, if not subdued. Whatever the promise, the shark will probably always be around, an inconstant, unlovable and unnecessary companion of man.
Biggest and worst of the killers is the great white shark, a rover of tropic and temperate waters that grows to a length of more than 20 feet. The smaller, slimmer Pacific mako, which, like the great white, can be distinguished from most other sharks by its crescent-shaped tail, is also dangerous but is rarely found in the shallows with man. The common hammerhead is a typical species of a bizarre family often sighted near popular beaches, and known to have been guilty of several attacks off Florida and South America.
A BAD FAMILY
The tiger is the worst of a dozen bad sharks in the large carcharhinid family, and because of its abundance in tropic and near-tropic waters, it actually causes more grief than the great white shark. The lemon shark, distinguished from others of the family by its large second dorsal, is an infrequent killer, but one found often in popular shallows of the western Atlantic and Caribbean. The white-tip, a carcharhinid rarely seen inside the 100-fathom line, is a particular threat to castaways on the Atlantic and Mediterranean.
Beyond the published literature the author and editors gratefully acknowledge the help and advice of the following: Dr. Richard H. Backus, Woods Hole Oceanographic Institution; J. L. Baughman, Texas Game, Fish and Oyster Commission; W. Douglas Burden, Marine Studios, Fla.; Dr. E. Milby Burton, Charleston, S.C. Museum; Dr. Harold Coolidge, National Academy of Sciences; Dr. V. M. Coppleson, Sydney, Australia; Charles Fischett, Babylon, N.Y.; Dr. Perry Gilbert, Cornell University; Francesca La Monte, American Museum of Natural History; Conrad Limbaugh, Scripps Institution of Oceanography; Dr. George Llano, National Academy of Sciences; William E. Ripley, California State Department of Fish and Game; William C. Schroeder, Woods Hole Oceanographic Institution; Stewart Springer, U.S. Fish and Wildlife Service; Dr. Gilbert Whitley, Australian Museum; F. G. Wood Jr., Marineland Research Laboratory, Fla.