Shark Facts: Attack Stats, Record Swims, More

[tekmac]

Just as a voice of reason in the late shark attack mania:


The United States averages just 16 shark attacks each year and slightly less than one shark-attack fatality every two years. Meanwhile, in the coastal U.S. states alone, lightning strikes and kills more than 41 people each year.

Which just goes to show that sharks enjoy a reputation that is arguably more fearsome than their bite. Read on for more surprising shark facts compiled by National Geographic News:

• Each year there are about 50 to 70 confirmed shark attacks and 5 to 15 shark-attack fatalities around the world. The numbers have risen over the past several decades but not because sharks are more aggressive: Humans have simply taken to coastal waters in increasing numbers.

• Over 375 shark species have been identified, but only about a dozen are considered particularly dangerous. Three species are responsible for most human attacks: great white (Carcharodon carcharias), tiger (Galeocerdo cuvier), and bull (Carcharhinus leucas) sharks.

• While sharks kill fewer than 20 people a year, their own numbers suffer greatly at human hands. Between 20 and 100 million sharks die each year due to fishing activity, according to data from the Florida Museum of Natural History's International Shark Attack File. The organization estimates that some shark populations have plummeted 30 to 50 percent.

• The shortfin mako (Isurus oxyrinchus) is often recognized as the world's speediest shark. It has been clocked at speeds of up to 20 miles an hour (32 kilometers an hour) and can probably swim even faster than that. Makos are fast enough to catch even the fleetest fish, such as tuna and swordfish.

• The largest shark is the whale shark (Rhincodon typus), which can grow to 60 feet (20 meters) long. The gentle giant eats tiny plankton.

• Among the smallest shark species is the deepwater dogfish shark (Etmopterus perryi). A habitué of the Caribbean, the dogfish measures a less-than-intimidating 8 inches (20 centimeters) in length.

• Sharks are known as eating machines. But because many species are cold-blooded, some sharks eat only about 2 percent of their body weight each day. That's a bit less than humans typically eat.

• While scientists still have much to learn about shark migration, researchers do know that some species get around. Blue sharks (Prionace glauca), for example, roam the North Atlantic on journeys of 1,200 to 1,700 nautical miles (2,220 to 3,145 kilometers). After one record-breaking blue was tagged off New York, it swam 3,740 nautical miles (6,919 kilometers) to Brazil.

• Some sharks must swim constantly to "breathe" oxygen from water passing through their gills. Other species can achieve this while stationary.

• Sharks do not sleep. Rather, they experience alternating periods of activity and rest.

• Sharks are among Earth's most ancient animals. The fossil record dates ancestors of modern sharks to as far back as 400 million years ago. Shark species have changed relatively little during that time span and are sometimes called living fossils.

• Sharks can replace lost teeth in as little as 24 hours and may use thousands of teeth over the course of a lifetime. Ancient teeth are the source of most known shark fossils. (Shark skeletons, which are composed of cartilage, decompose quickly.)

• Sharks are diverse reproducers, and their mating has been observed only on rare occasions. Some species are egg-laying (oviparous), while others bear live young (viviparous). Adult sharks do not care for their newborn pups, which are born or hatched as smaller, juvenile versions of their parents.

• Two shark species can survive long periods in fresh water: the bull shark and the speartooth shark (Glyphis glyphis). Both species can engage in river journeys of epic scale. Bull sharks, for example, have been caught 1,700 miles (2,800 kilometers) up the Mississippi River and 2,100 miles (3,480 kilometers) up the Amazon. Neither species, however, lives in landlocked fresh water without ocean access.

• A major cause of shark mortality is "finning," a process in which fishers kill sharks solely to remove their fins. Fins can sell for U.S. $400 per kilogram (U.S. $880 per pound) or more.

Known in China as yu chi or "fish wings," shark fins are used to make the traditional delicacy shark-fin soup. The culturally celebrated but controversial soup is found widely in Asia and will even be on the menu at Hong Kong Disneyland when the park opens in September.

• Sharks are apex predators, and as such, they affect the entire ocean food chain from their position at the top. Because of their dominant role, sharks have long life spans and don't reach sexual maturity until they are 12 to 20 years old. Even then, sharks have low reproductive rates. Such predator populations, once diminished, have a hard time bouncing back.

• As elasmobranches, sharks have skeletons made not of bone but of cartilage, tissue similar to that found in human noses and ears. Cartilaginous skeletons are lighter than bone and help sharks to remain neutrally buoyant (able to float without sinking or rising).

• The media can have a voracious appetite for "shark bites man" stories. The summer of 2001, for example, saw an explosion of shark-attack hype and was even heralded on the cover of Time magazine as the "Summer of the Shark." Yet 2001 was statistically average: The year saw 76 shark attacks and 5 fatalities worldwide, compared to 85 attacks and 12 fatalities in 2000.

• Thirty years ago the blockbuster Jaws brought the terror of shark attack to movie theaters. The record-breaking film, directed by Steven Spielberg and based on a best-selling novel by Peter Benchley, grossed nearly 130 million dollars (U.S.) in the United States alone. The movie arguably made sharks public enemy number one.
Source-National Geographic News

[LSDeep]

CAPE TOWN, South Africa (15 June 2005) -- A South African group has called on the South African government to ban shark feeding.

The group of renowned scientists, researchers, doctors, environmentalists, tour operators, fishermen, divers and surfers have sent an open letter to South Africa's Minister of Environmental Affairs & Tourism citing its concerns about the impact of shark feeding on both public safety and the environment, and have demanded that the government ban all "chumming" and feeding of sharks in South African coastal waters.

The letter (see below) emphasizes the eco-friendly nature of non-feeding shark encounters which would provide South Africa's shark tour operators and customers with opportunities to witness natural shark behavior that is exciting, educational and environmentally responsible.

June 15, 2005
Cape Town, South Africa

OPEN LETTER TO THE MINISTER OF ENVIRONMENTAL AFFAIRS & TOURISM

Honourable Minister

I am writing this letter to you on behalf of a Shark Concern Group. The names of its members are listed below. We request urgent action to ban the use of baits, attractants and "chumming" for shark viewing by tourists in South Africa.

On the 24th of December 2002 I was attacked by a Great White Shark whilst diving for crayfish off Scarborough Point for my family's Christmas dinner. I am fortunate to have survived with a disability to my right hand. Now, almost 30 months and another 5 attacks in the Cape Town area later, I feel that I have become part of the "shark fraternity".

From enjoying our ocean in a state of ignorance & abandon, the local diving & surfing community has rightfully become increasingly concerned about shark attacks. We are concerned that the risks have increased, and could further increase, as a result of how humans are interacting with
sharks, for example using shark cage diving & chumming. These practices are unnecessary and have ecological implications that are largely unknown.

In the film "Air Jaws", Chris Fallows describes witnessing more than 300 successful natural predations (kills on seals) & slightly fewer unsuccessful ones over a period of a year or so. This was done without any chumming or close human intervention & is described by Chris as being "one of the most magnificent sights to view in nature!" We propose boat-based shark viewing without the use of attractants.

This sort of shark tourism would be true eco-tourism. It would cater to a wider group of tourists, also attracting a more discerning tourist preferring a natural WILD experience! As Dr. Leonard Compagno says, it would also be better for the sharks, the general ecosystem and the type of research that he is engaged in.

We urge that Great White Sharks be given the same protection that they enjoy in other parts of the world, where any interference with the shark is expressly forbidden. We urge that shark diving and viewing practices in South Africa be brought in line with our proud status as signatory of CITES and as a global leader in nature-based tourism.

If we do not know whether or not chumming has an affect on Great White Sharks then a precautionary approach should be adopted as a matter of extreme urgency. A Strategic Environmental Assessment (SEA) with full public participation should be held to review the options.

We eagerly await a response from MCM and DEAT in order to open negotiations around this matter.

Craig Bovim
Chris Lomax (world renowned climber & film producer)
Wally Petersen (Kommetjie Environmental Awareness Group)
Dr. Graham Noble (zoologist)
Dr. Phil Desmet (conservation biologist)
Ian Armstrong (champion surfer)
Pierre deVilliers(world renowned surfer)
Greg Bertish (The surfers board ; a community based shark spotting
initiative)
Phillipe Carosin (professional fisherman)
Capt. At DuPlooy (Executive Officer, South African Institute of
Skippers)
Russell Weston (Nature tour operator)
Bernadette Shelly (Secretary S.A Longboard Association)
Steve Pike (Wavescape, surf tourism information)
Ian Ainslie (Olympic yachtsman)
Glenn Ashton (writer, researcher & environmental activist)
Dr. Brian Bernstein (Orthopaedic surgeon & surfer)
Terry Corr (Marine Environmental Education Trust)

[LSDeep]

Stefan Lovgren
for National Geographic News
June 15, 2005

Thirty years ago, in the summer of 1975, Jaws had moviegoers paralyzed by fear. The story, about a giant great white shark that terrorizes a seaside community, tapped into the most primal of human fears: What unseen creature lurks below the ocean surface?

Millions of beachgoers heeded the advice of the movie's tagline—"Don't go in the water." They filed into theaters instead, and Jaws became the biggest box office hit to date.

To the dismay of many scientists, however, Jaws cemented a perception in the minds of many people that sharks were stalking, killing machines. The reputation remains entrenched in the public psyche 30 years after the movie's release.

"It perpetuated the myths about sharks as man-eaters and bloodthirsty killers … even though the odds of an individual entering the sea and being attacked by a shark are almost infinitesimal," said George Burgess, a shark biologist at the University of Florida in Gainesville.

Burgess says the movie initiated a precipitous decline in U.S. shark populations, as thousands of fishers set out to catch trophy sharks after seeing Jaws. Later, in the 1980s, commercial fisheries further decimated shark populations.

But the phenomenal popularity of the movie also helped the study of sharks, researchers say. Before Jaws, very little was known about the predators. After the film's release, interest in sharks skyrocketed, resulting in increased funding for shark research.

"On the one hand, the movie did damage to sharks, because people saw them as monsters," said Robert Hueter, who directs the Center for Shark Research at the Mote Marine Laboratory in Sarasota, Florida. "But for scientists, the whole Jaws thing started working in our favor, because of the overexaggerated public interest in these animals."

Mechanical Shark

In the hands of a young director named Steven Spielberg, Jaws, which was based on the best-selling novel by Peter Benchley, was widely hailed as a masterful thriller. Its music score, by John Williams, contains one of the most recognized themes in movie-music history.

Filming was plagued by technical problems. Scenes with a mechanical shark had to be cut, because it did not look believable enough. That, however, only made the movie scarier, heightening the unsettled feeling of helplessness that many moviegoers felt toward the beast, which remained largely unseen.

"The fear of being eaten is ingrained in people," said Mike Heithaus, a marine biology professor at Florida International University in Miami. "If we feel like we have some control or fighting chance, a situation isn't as scary. With sharks there are no trees to climb, and you can't outswim a shark."

Real-life shark attacks, though widely publicized, are extremely rare. People in U.S. coastal areas, for example, are about a hundred times more likely to be struck and killed by lightning than killed by a shark. According to the Florida Museum of Natural History's International Shark Attack File, there were 61 unprovoked shark attacks worldwide in 2004, resulting in seven deaths.

"Those are ridiculously low numbers when you consider the billions and billions of human hours spent in the water every year," said Burgess, who curates the Shark File.

Kill Tournaments

The number of shark attacks has increased over the past several decades, but that is because humans are going into the water in increasing numbers.

Humans are not part of sharks' normal prey.

"Most sharks don't attack prey that is close to their own size, and they can be wary of strange situations or objects they're not used to, like humans," Heithaus, the Miami marine biologist, said. "This makes attacks very unlikely, even if a hungry shark sees a person."

But sharks have suffered greatly at human hands. Between 20 to 100 million sharks are killed by fishing each year, according to the Shark File, which is administered by the American Elasmobranch Society, whose members study sharks, skates, and rays. The organization estimates that some shark populations have plummeted 30 to 50 percent.

That decline can be traced in part back to Jaws. In the years after the movie's release, the number of so-called kill tournaments spiked.

"There was a collective testosterone rush that went though the U.S. in the years following Jaws, where guys just wanted to catch these sharks so they could have their pictures taken with their foot on the head of a man-eater and the jaws later displayed on their mantle," Burgess said.

Biological Buck

When Jaws premiered, scientists knew little about sharks, partly because they were considered a nuisance by fisheries.

"The most important commercial species always get the biological buck in terms of grants and money," Burgess said. "Nobody cared much about sharks. They ate good fish, so they were considered bad by fisheries."

In the 1980s U.S. commercial fisheries turned their attention to sharks. Commercial overfishing further depleted the number of sharks. As shark populations declined, marine ecosystems suffered.

"As a result, we soon started getting funding from fisheries to do basic research on sharks—how old they get, how fast they grow, how many young they make," Burgess said.

Scientists have since learned that sharks, as apex predators, can affect the entire ocean food chain from their position at its top.

Most people, when they hear the word "shark," may still think of a huge great white shark, like the one in Jaws. In reality, there are more than 375 shark species, and only about a dozen are considered particularly dangerous.

But the public is slowly learning, scientists say.

"In the final analysis, Jaws has been a positive thing for the science of sharks," Hueter said, "because it has elevated the public's interest in these animals."

[LSDeep]

First, find your shark.
By Brendan I. Koerner

Australian wildlife officials are hunting for a great white shark that killed an 18-year-old surfer near Adelaide on Thursday. How common is the practice of killing sharks believed responsible for fatal attacks?

Not very, in large part because it's incredibly difficult to find the guilty party. Sharks can swim over 40 miles a day and often bolt from the scene of an attack soon after the incident. "The high mobility of individual sharks … indicates that fishing for a 'culprit' after an attack is unlikely to be effective," concluded members of the Hawaii Institute of Marine Biology's Shark Research Group in a 1999 paper. Heeding that advice, wildlife officials around the world rarely send fishermen on search-and-destroy missions after a fatal strike.

There also seems to be little scientific basis for hunting down a particular shark. Despite what you might have seen in Jaws, there is no such thing as a "rogue shark" that develops a taste for human flesh. In fact, a shark that attacks a human is unlikely to do so again—we are by no means their preferred prey.

Would-be avengers also face legal barriers, especially when a great white shark is the suspect. In Australia, South Africa, and California, three of the epicenters of the great white's activity, the infamous species is protected by law. Before an individual can be hunted, wildlife authorities must grant special permission—as occurred in the current case. Even then, the odds of locating the appropriate shark are slim. When the Australian government granted permission for a shark hunt in 2000, after a similarly lethal attack, fishermen came up empty despite weeks of effort.

Less restraint was shown in bygone days, when shark attacks sometimes inspired mass waves of indiscriminate killing. In 1916, for example, when several attacks occurred around New Jersey's Matawan Creek, locals peppered the waterway with dynamite and gunfire, killing untold thousands of fish. (A "Matawan Man-eater" whose belly contained human flesh was eventually killed, though many historians now theorize that attacks were the work of multiple sharks.) And in the late 1950s, after a Hawaiian surfer was killed by a tiger shark, the state launched an eradication program that ended up destroying thousands of sharks. No one knows, however, whether the true killer was among the victims.

Next question?

Brendan I. Koerner is a contributing editor at Wired and a fellow at the New America Foundation.

[LSDeep]

Incidents are isolated, coincidental, according to Gruber

MSNBC
Updated: 1:20 p.m. ET June 28, 2005

After two shark attacks off of the Florida panhandle in three days, MSNBC's Randy Meier spoke with renowned marine biologist Dr. Samuel H. Gruber on Tuesday to learn more about attacks. Gruber is both a professor at the University of Miami and the director of the Bimini Biological Field Station, one of the foremost shark research facilities in the world.

Concern about both the victims and the close proximity of the attacks have led to a great amount of speculation surrounding each shark's motivations. Gruber said the answer is much simpler than most believe.

"This is a random occurrence," he said. "There are no more sharks, sun spots didn't do it, the hurricanes didn't do it and global warming didn't do it, this is just a fact of a natural animal in its natural environment."

He applies this same notion to the questions posed about the proximity of the two attacks, which took place approximately 80 miles apart. "We simply do not have the tools to make that kind of prediction, the statistics are not helpful." Gruber noted.

There is a lack of information among the general public about hark attacks, according to Gruber. Only certain (shark) species would actually consider a human being as legitimate prey," he said. "Most shark attacks are a bump or perhaps an exploratory bite and then they're gone."

The species in question in the two recent attacks is the bull shark, which makes its home in salt water, lakes, rivers and hard against the shore. "They encounter humans from time to time and they're not afraid" Gruber noted.

[tekmac]

And is it a good idea to punch one in the face?
By Daniel Engber
Posted Monday, June 27, 2005

A shark attacked and killed a 14-year-old girl near a Florida beach on Saturday, despite a surfer's attempts to save her. The surfer pulled the girl from bloody water, fended off the predator (probably a bull shark) with his fists, and tried to confuse the predator by splashing around away from the girl's body. Can sharks really smell blood in the water?

Yes. Sharks have a keen sense of smell, and blood happens to be a very attractive odor—they can sniff out even a tiny amount diluted into a large body of water. Sharks also use sight and hearing to detect their prey. A splashing sound might tempt them, as would the sight of a flailing animal. In particular, hungry sharks like to hear low-frequency, irregular sounds, like those made by a struggling fish. They also look for flickering shapes, like a fish's glinting scales. Attacks on people can sometimes be a case of mistaken identity. For example, a shark could confuse reflective jewelry for scales.

The shark's eyes, ears, and nose are all situated near its mouth. But sharks also detect their prey with sensory receptors that run along their sides. These receptors make up the "lateral line," an organ similar in function to the ear that can feel pulses or vibrations in the water. A shark might sense the flailing of an animal in distress and swim closer to investigate.

When a shark gets very close to potential prey, it can utilize yet another sense: electroreception. Electroreceptive organs (or "ampullae of Lorenzini") sit inside little pores on the shark's snout. Living things submerged in salty seawater produce a faint electrical field that the shark can feel at short distances, allowing it to suss out creatures that bury themselves in the sea floor. Muscle contractions also produce little surges of electrical activity that a shark can detect using electroreception. (Research suggests that some sharks may use electroreception like a compass, to help navigate underwater.)

Bonus Explainer: The surfer who tried to save this weekend's shark attack victim says he defended himself by punching the shark with his bare fist. Is that a good idea? Shark attack experts suggest punching a shark only as a last resort. Rapid retreat tends to be a better plan. It won't help to play dead if a shark has you cornered. Instead, a smack to the face or snout—where sharks, like humans, have a high concentration of sensory receptors—can stun your attacker and give you enough time to escape. When a shark has you in its jaws, try poking at its eyes or gills.

[tekmac]

June 29, 2005 6:53 a.m. EST

Hector Duarte Jr. - All Headline News Staff Reporter

Miami, Florida (AHN) - With two shark attacks in three days off popular Florida beaches, experts are warning this may just be the beginning, as during summer months more tourists go in the water, and sharks swim closer to shore.

George Burgess, curator of the International Shark Attack File at The University of Florida in Gainesville, said Craig Adam Hutto, 16, the boy attacked Monday while fishing in waist-deep water off The Florida Panhandle, was likely attacked by a bullshark, roughly 7 to 8 feet long.

Burgess tells The Associated Press that bull sharks are common throughout the Gulf and tend to swin in shallow waters.

John Tyminski, a senior biologist at the Center for Shark Research at Mote Marine Laboratory in Sarasota, agrees that in summer sharks tend to come closer to land in search of food, which ironically coincides with more people heading in the water. "It's a sharky time of year," he adds.

Samuel Gruber, professor of marine and atmospheric sciences, says there is no predictable behavior or pattern as to why these attacks occur, stating that when there is a larger number of people in the water, coupled with more sharks, there will be more instances of attacks.

One report claims last year's Hurricane Ivan shifted sandbars along the nothern coast of The Gulf of Mexico, prompting sharks to swim closer to shore.

"I know of no scientific evidence to support that," Burgess said.

According to statistics for 2000, the chances of being attacked by a shark in Florida waters are one in 11.5 million; the chance of being killed by a lightning strike is higher. It is interesting to note that between 2000-2003, over 30 shark attacks occured in Florida, but only 12 were reported.

Experts at the Florida Museum of Natural History have tips to reduce the risk of a shark attack:

* Always stay in groups since sharks are more likely to attack a solitary individual.
* Avoid being in the water during darkness or twilight hours when sharks are most active and have a competitive sensory advantage.
* Do not enter the water if bleeding from an open wound or if menstruating as a shark’s olfactory ability is acute.
* Wearing shiny jewelry is discouraged because the reflected light resembles the sheen of fish scales.
* Avoid waters with known effluents or sewage and those being used by sport or commercial fisherman.
* Use extra caution when waters are murky and avoid uneven tanning and bright colored clothing, sharks see contrast particularly well.
* Refrain from excess splashing and do not allow pets in the water because of their erratic movements.
* Do not enter the water if sharks are known to be present and evacuate the water if sharks are seen while there.

[tekmac]

The science of shark attacks
What provokes them, and what you can do to avoid them

By Bjorn Carey
Updated: 1:08 p.m. ET July 5, 2005

Despite two highly publicized shark attacks last month along the U.S. coast, at least one scientist says it's safe to go back in the water.

In fact, he points out that you're actually in more danger on the way to the beach.

"There are millions of people in the water at any given moment of the day," said John McEachran of Texas A&M University. "When you consider all of the people in the water at the same time, the number of shark attacks is very, very remote."

Every year across the globe, nearly one million people die in automobile accidents. More than 42,000 of those deaths occur in the United States.

Shark attacks resulting in deaths occur much less frequently than car wrecks, but they get much more publicity.

"Shark attacks are like airplane crashes," said McEachran. "The vast majority of airplane trips are safe, but when a crash occurs, it gets big headlines."

According to the International Shark Attack File, in 2004 there were only seven shark related deaths worldwide. That number was even smaller in 2003 and 2002, when four and three deaths were recorded respectively.

Should you get to the beach safely, there are still plenty of bigger risks to your health than a shark attack.

"A greater percentage of beachgoers are injured by jellyfish, stingrays, or hardhead and gafftop fishes, which have poisonous spines," McEachran said. "They are more likely to cause harm than a shark."

Even peanuts, McEachran says, are a greater threat to humans than sharks. About 90 people die worldwide each year from allergic reactions to eating peanuts.

There's a better chance you'll win the lottery than be bitten by a shark.

You're not dinner
Should you be bitten by a shark, it's not just bad luck for you. Sharks don't really like eating humans. They'd rather snack on a seal or sea lion – something with higher fat and energy content. We're too bony.

"Sharks don't eat humans," shark exert Peter Kimley of the University of California, Davis told LiveScience. "They spit out humans. Humans aren't nutritious enough to be worth the effort."

But most sharks don't have very good vision, and sometimes objects like buoys and people look similar to a seal — a shark's favorite meal.

"A human being of course, close to the surface, does a pretty good job looking like a seal, and one on a surfboard does an even better job," George Burgess, curator of the International Shark Attack File told LiveScience. "It's not like they're out there saying 'let's try to find a human today."
Most often, sharks spit people out after carrying them underwater for a ways. Because their eyesight isn't very good, they need to feel objects over with their mouths to decide whether they want to eat them or not.

Humans are usually spat out. Unfortunately, by that time they've either drowned or have bled to death.

How to avoid a shark
The best thing to do when you see a shark is move away, experts say. Move swiftly but calmly — sharks are attracted to splashing. If the shark is already swimming at you, no need to go quietly. Just get away.

If a shark bites you, try to get away before it takes you under for too long. Hit it on the snout, head, and eyes, and it may let you go.

Not all the blame for shark attacks falls on the beasts.

Attacks are more frequent in summer months, Burgess said, because "both sharks and humans have seasons where they want to be in the water at the same time."

Sometimes sharks bite because people provoke them, either by putting food in the water or grabbing one as it swims by. Other times, it's just because someone is in the wrong place at the wrong time. Surfers often unknowingly put themselves in one of these wrong places. The good breaks they crowd around are often created by seamounts on the ocean floor, which are popular feeding areas for sharks.

While the number of shark attacks and deaths is still much lower than car wrecks, attacks have been climbing steadily.

"Decade to decade you find that the number of shark attacks has continued to rise," Burgess said. "This is largely because the human population and interest in water activities has grown."

So what's the prudent course?

"If you use some good common sense in the water, you should be fine," said McEachran. "To put your mind at ease, go to a beach that has lifeguards. They should be looking for possible sharks."
Source-LiveScience.com

[tekmac]

By RUSS HENDERSON
Staff Reporter - Mobile Register

DAUPHIN ISLAND -- After a snack of peanut butter and jelly sandwiches late Tuesday afternoon, Sarah Thompson sat on a towel and watched her two girls scamper across the sand to the cinnamon-colored surf at the island's public beach.

"I'm not going to carry a gun with me to the beach, but sometimes I wish someone would," the Mobile resident said with a laugh. "Really, I try to watch for shadows in the water when they're out there. You have to live your life and swim at the beach sometimes."

Thompson is not alone when it comes to keeping a more careful eye out for sharks these days, the results of a new statewide survey suggest. Almost half of respondents to the Mobile Register-University of South Alabama poll said they would be less likely to swim in the Gulf of Mexico following two recent shark attacks in Florida.

Fifty-five percent, however, said they would oppose a public policy of killing sharks that come too close to public swimming areas. Slightly over a third would support such a policy.

The poll was conducted after two separate shark attacks last month at Panhandle beaches that killed a 14-year-old girl and critically injured a 16-year-old boy. Bull sharks, which nest and often feed in shallow Gulf waters, are thought to be responsible for the attacks. The telephone survey of 401 adult Alabamians was conducted July 4-7.

Seventy-two percent of respondents said the media devoted about the right amount of attention to the attacks, while 13 percent said they got too much attention. Meanwhile, about half said government does enough to protect citizens from such attacks, such as conducting public education and posting signs. A third said government should do more.

"Every year around this time, there's a cluster of shark attacks and this contingent comes out that says: 'Let's go out and kill these animals,'" said Robert Hueter, director of the Center for Shark Research at the Mote Marine Laboratory in Sarasota, Fla.

He likened the idea to using atomic bombs to break up hurricanes.

"It's not the same thing, of course, but neither is a very reasonable approach," he said. "Even if it were effective, radioactive fallout would be scattered for thousands of miles, it could cause all kinds of unpredictable ecosystem changes."

Likewise, killing off sharks would create ecosystem changes, like the death of many coral reefs in the Caribbean caused by excessive shark fishing in recent decades, Hueter said.

Caribbean longline fishermen, by catching bull sharks and Caribbean reef sharks by the thousands, created a population boom among the mid-level predators those sharks usually eat. Those mid-level predators, in turn, ate more of their own prey than usual, including plant-eating fish that had kept algal blooms in check. Algal blooms then spread and killed the reefs, he said.

Also, sharks migrate near populated coasts every year. So a policy of killing sharks that come close would mean "killing a whole lot of sharks. And since shark attacks are rare, it wouldn't be cost-effective," Hueter said.

Bull sharks are generally regarded as the most dangerous shark to humans along the Gulf Coast. The main reason its highly adapted gills, which are extremely freshwater tolerant, meaning they can swim in near-coastal and inland waters humans frequent.

Indeed, the sharks are not only capable of swimming at the beaches near populated coastal areas, bulls have used those same areas as nesting grounds for thousands of years, Hueter said. And some of the bull shark's natural prey, such as dolphins and other sharks, are human-sized.

A large majority of Alabamians, 60 percent, responding to the poll said they would support banning many diving companies' practice of attracting sharks with food to make their customers' diving experience more exciting.

John Davies, a Grand Bay resident also on the Dauphin Island beach Tuesday, said "teaching sharks to associate people with food is insane."

Hueter disagreed.

"If these programs are done right, like the ones you can find now in the Bahamas, the sharks really become almost domesticated and the feedings become something like an aquarium experience," Hueter said. "People's ideas about sharks change. The customers see how beautiful, graceful and non-aggressive they can be."

Further, the number of shark attacks in the Bahamas hasn't increased over the past decade, the time when such diving experiences became a major industry, he said.

The poll also found many Alabamians, 42 percent, would oppose a ban on commercial shark fishing, versus 37 percent who would support a ban. More than 50 percent of respondents said they'd oppose a ban on recreational fishing.

Last year, there were 61 shark attacks worldwide, seven of them fatal, according to the International Shark Attack File. Thirty of them were in the United States. Twelve were in Florida, none of which were fatal.

On the other side of the ledger, commercial fishermen in the United States caught 14 million pounds of shark in 2004, 97,000 pounds of it bull shark, according to federal fisheries statistics.