Sometime last weekend a three-meter female tiger shark snared itself on a hooked line that was attached to a floating drum just off the southwestern coast of Western Australia. A commercial fisherman later motored by and, with the blessing of the government, shot it in the head. Four times.

The controversial cull began this weekend as a response to the deaths of seven people over the past three years at the hands – er, teeth – of sharks in Western Australia. At a press conference the state’s premier, Colin Barnett, said, “I get no pleasure from seeing sharks killed, but I have an overriding responsibility to protect the people of Western Australia, and that’s what I’m doing.” Protecting swimmers and other beachgoers is indeed important, but are culls even effective in the first place? And are there other methods that are better able to both protect swimmers and the sharks that many would rather avoid?

While the scientific data on the effectiveness of shark culls is scant, what data is available suggests that they aren’t terribly effective. In a 1994 paper in the journal Pacific Science, University of Hawaii researchers Bradley M. Wetherbee, Christopher G. Lowe, and Gerald L. Crow took stock of nearly two decades of shark control programs in Hawaii.

The programs were implemented with two main objectives. The obvious aim was to reduce the number of sharks in the water. In addition, data was collected from the sharks that were captured in order to add to the body of knowledge on shark biology. If the sharks were going to be killed, at least scientists could benefit from the data. At least, that was the idea.

But Wetherbee and colleagues reported that only one scientific paper derived from the shark cull data was ever published. As a result, the reports made by those who carried out the culls went unchallenged by the formal peer review process. And while the reports declared the culls successful insofar as fewer sharks were caught as time went on, a correlation does not prove causation. The researchers point out that while “the removal of nearly 4700 sharks from Hawaiian waters over an 18-yr period undoubtedly resulted in a substantial decrease in the population, and declines in shark abundance are evident in reduced catch rates in long-running programs,” other factors that could have contributed to that decline were never considered, such as predictable seasonal shifts in local shark populations, or weather patterns, which not only drive changes in shark behavior but also have a tendency to foul fishing efforts.

More damning evidence comes from the finding that there was no statistical difference between the average number of attacks per year for the eighteen years prior to the first control program and the eighteen years in which control programs were intermittently implemented. “Consequently,” Wetherbee writes with an excessive amount of understatement, “conclusions made about the effectiveness of the programs in reducing shark populations might well have been stated with less confidence.”

If culls don’t seem to work, are there any other methods for making swimmers safer? Gill nets have been shown to be effective at reducing shark encounters, but they have the downside of indiscriminately catching dolphins, dugongs, turtles, birds, rays, tuna, other non-dangerous sharks, and even whales as well. And the removal of larger sharks from the sea by drowning them in gill nets has led to the proliferation of smaller sharks in some areas, which in turn compete with fishermen for the same fish stocks. Indeed, removing apex predators can have widespread effects on the entire ecosystem, something that was made obvious with the removal and subsequent reintroduction of wolves fromYellowstone National Park.

A 2013 paper in the journal Animal Conservation describes a more welfare-oriented, ecologically conscious approach to shark attack mitigation in Recife, Brazil. The problem was that 55 shark attacks were recorded along a twenty-kilometer stretch of coastline between 1992 and 2011, 19 of which resulted in fatalities. As a result, the state government created a Committee for the Monitoring of Shark Attack Incidents, which formulated a new strategy to manage the risk of shark attacks. The guiding principle was removing sharks from high-risk areas rather than from their populations. It was actually quite simple: sharks were captured, transported, and released farther from shore. If effective, the reasoning went, such a strategy would reduce the risk of shark-human encounters while also maintaining the structure of coastal ecosystems.

Not only did the catch-and-release method avoid creating a massive ecological upset, but it was also overwhelmingly effective. Between 2004 and 2011, the shark relocation program was in operation for 73 months, and was inactive for 23 months due to funding shortfalls. Thus, researchers were able to compare the frequency of shark attacks while the program was active to months it was on hold. While the program was operational, Recife saw an impressive 97% reduction in the monthly shark attack rate.

While the shark cull program began in Western Australia last week, groups of Japanese fisherman continued their annual dolphin slaughter. It is perhaps not surprising that the kind of outrage directed towards the Japanese town of Taiji has not been aimed towards Western Australia. The cultural narrative that surrounds dolphins is one of friendliness. Dolphins are thought of as smart, playful tool-users, their faces plastered in a permanent smile. Sharks, on the other hand, are traditionally seen as little more than sets of flesh-shredding steak knives with fins. Of course neither tale is complete. Dolphins can bejerks and sharks can actually be quite clever. As shark scientist David Shiffman wrote in a recent blog post, perhaps the best strategy to avoid the needless slaughter of sharks is simply better education. Maybe swimmers can simply be taught the most effective behaviors for reducing the risk of an unfortunate encounter. Combined with a catch-and-release program, humans could then safely enjoy our brief visits to the sea. – Jason G. Goldman | 29 January 2014

Wetherbee B.M., Lowe C.G. & Crow G.L. (1994). A Review of Shark Control in Hawaii with Recommendations for Future Research, Pacific Science, 48 (2) 95-115.

Hazin F.H.V. & Afonso A.S. (2013). A strategy for shark attack mitigation off Recife, Brazil, Animal Conservation, n/a-n/a. DOI:



How to prevent shark attacks

A combination of government policy and personal responsibility will keep us safer from sharks than culls will. AAP Image/Rebecca Le May

In light of the most recent shark bite fatality in Western Australia (WA) last week, there have been renewed calls for a cull of large sharks to protect ocean users. Environment minister Greg Hunt has said he wants to reduce the risk of attacks. So what is the best way to reduce that risk?

Are shark bites increasing?

There is no denying that each of these events is a tragedy and our sympathy is, of course, with the family and friends of the victims. However, based on statistical data, the number of shark related fatalities is negligible when you consider the vast and increasing number of swimmers entering our coastal waters every year.

Research has shown the number of shark bite incidents occurring each year appears to be directly related to the amount of time people spend in the sea. Given that Western Australia has the fastest population growth of any Australian state, there is likely to be an increasing number of people venturing out into our coastal waters every year. Thus, the likelihood of someone encountering a shark increases and with it a corresponding increase in shark bite incidents.

Politicians and the public are often quoted in the media saying shark numbers in WA have increased. But most experts would agree that there is no evidence to support such a statement.

Data gathered by Surf Life Savers WA has been used to suggest an increase in the number of sharks in WA, by stating that more sharks were sighted in 2012/13 (285 sharks) than in 2011/12 (247 sharks).

However, when you account for the number of hours that the helicopter patrols were out looking for sharks (2012/13: 751 hrs; 2011/12: 620 hrs) we find that they sighted the same number of sharks per hour of patrolling (approximately 1 shark every 2.5 hrs).

In fact, research shows that the number of attacks per million people in Australia almost halved from approximately 60 per million people between 1930/1939 to approximately 30 per million people between 2000/2009.

Does culling work?

So often the argument in favour of a cull comes down to the emotional question of who is more important: a human or a shark. Rather, we need to ask the question, will culling sharks actually reduce the risk of an attack?

The answer is no. In fact, when shark culling was carried out in Hawaii, between 1959 to 1976, over 4,500 sharks were killed and yet there was no significant decrease in the number of shark bites recorded.

Culling has been the primary shark mitigation policy of the New South Wales Government for over 60 years, through the use of “shark” nets. But a report by the Department of Primary Industries showed that 24 of the 38 (63%) attacks in the state, between 1937 and 2008, occurred at netted beaches.

Pre-emptively killing sharks is a response based on emotion rather than of scientific data.

How to reduce personal risk

We take a calculated risk whenever we enter the ocean, but the risk is quite small when compared to other daily activities. For example, new research shows that rip currents are the cause of an average 21 confirmed human fatalities per year in Australia, compared with 7.5 for cyclones, 5.9 for bushfires, 4.3 for floods, and 1 for sharks.

With the correct information, we can make an objective judgement as to whether or not we accept the risk to enter the oceans.

The WA Department of Fisheries recently released a report on how to reduce your personal risk of being bitten by a shark (and you can find more information at theInternational Shark Attack File).

  1. Stay out of the water if sharks have been sighted in the area.
  2. Stay close to shore (within 30m of the water’s edge).
  3. Don’t go in the water alone (stay in groups).
  4. Avoid water temperatures lower than 22C.
  5. Avoid water depths of greater than 5m when swimming or surfing.
  6. Avoid swimming after heavy storms, or in low light conditions (dusk and dawn).
  7. Avoid swimming if there are seals, dolphins, whales or baitfish nearby.

What the government can do

The WA Government are in a difficult situation. They genuinely want to protect ocean users, but at the same time they are well aware there is no “magic bullet” to prevent shark attacks across the large expanse of the WA coastline.

Their investment in monitoring and research has been a very positive step towards reducing shark bite incidents in the region, but the use of lethal control measures and the threats of a major cull of sharks is not the answer.

Instead, we need to better understand exactly what causes sharks to bite people, what factors are responsible for them venturing closer to shore and more about their biology and life history. Recent research has found, for example, that sharks’ diving behaviour is affected by temperature and the moon, that female white sharks have different movement patterns to males, and that Australian white sharks have home territories they always return to.

This kind of research helps us better understand where sharks will be and how they’re likely to behave. More of the same could help us develop strategies to coexist with these important apex predators and continue to enjoy the ocean safely.

The WA Government should also consider placing more emphasis on educating people about the risks, such as the times of day and conditions under which attacks are most likely to occur.

They could also put warning signs at beaches known to be frequented by “dangerous” sharks. We are unaware of a single beach in WA that has information boards related to the risks associated with encountering potentially dangerous sharks. This strategy is common practice in California and other places frequented by large sharks.

We will never completely prevent shark attacks, however, with better education and improved investment in monitoring and research we can reduce the risk and frequency of these tragic events.


Sharks are necessary for the ecological health of coral reefs

FOR decades, rangers in Yellowstone National Park, in the American West, had to cull the area’s red deer (known locally as elk, though they bear no resemblance to European elk, known locally as moose) because the animals’ numbers were grazing the place to death and thus threatening the livelihoods of other species. Many ecologists argued that the deer had once been kept under control by wolves, which had been hunted to extinction by people. When wolves were reintroduced to Yellowstone, in 1995, these arguments proved correct. The deer population fell to manageable levels, and culling stopped. Wolves, it turned out, played a crucial role in keeping the wider ecosystem intact. Now comes evidence that the same is true for another top predator: sharks.

Jonathan Ruppert of the University of Toronto, in Canada, and his colleagues reached this conclusion by studying data on shark activity around two groups of coral reefs between Indonesia and Australia. They gleaned their information from baited underwater video stations and also from records collected from those reefs between 1994 and 2008 by the Australian Institute of Marine Science. They have just published their results in the Public Library of Science.

The reef-groups in question, known as the Scott Reefs and the Rowley Shoals, are close to each other. They experience similar sea temperatures. And both were hit by powerful cyclones and affected by coral bleaching in the mid-1990s. One, however, turned out to be rich in fish species whereas the other is impoverished, and the one with more species seemed to recover faster from the storms and the bleaching. Dr Ruppert believes these differences are the result of the presence in one, and the absence in the other, of sharks.

The impoverished group, the Scott Reefs, has been fished for centuries by people interested in catching sea cucumbers, certain snails and sharks—all of which are internationally traded and fetch high prices. In recent decades the demand for sharks, in particular, has boomed, as China has grown richer and its citizens have been supping more shark-fin soup. The Rowley Shoals, by contrast, are a protected area where all fishing is prohibited.

It is hardly a surprise that fishing reduces a reef’s species diversity. But what did surprise Dr Ruppert and his colleagues was exactly how that diversity was diminished. For besides the species that fishermen are hunting (silvertip and grey reef sharks were three times as common around the Rowley Shoals as around the Scott Reefs), many other sorts of animal had suffered.

This was not because they were being caught accidentally. Sea cucumbers and snails are hand-picked by divers, and sharks are caught on lines, rather than in nets, with bait that attracts only carnivores. All this means there is little bycatch. Yet the Scott Reefs also lacked herbivorous species such as parrotfish, though midsized predators, like snappers, were more abundant than in the Rowley Shoals.

Dr Ruppert thinks that eliminating sharks means populations of the midsized predators they feed on rise and those predators’ prey then suffer the consequences. Hence the reduced numbers of parrotfish. Their absence, however, has knock-on effects. Seaweed grows more thickly without parrotfish constantly gnawing at it. That growth smothers young coral and probably, though Dr Ruppert cannot prove it in this particular case, makes it harder for reefs to recover from cyclones and bleaching. Healthy reefs, then, seem to need sharks in the way that healthy forests need wolves. It’s not much fun if you are a snapper or a deer. But Mother Nature prefers it that way.


What do wolves and sharks have in common?

by Jeremy Hance

Sharks dwell in the ocean, wolves on land; sharks are a type of fish, wolves are a mammal; sharks go back some 400 million years, wolves only some 2 million years. So, these animals should have little in common, right? However, a new study inFrontiers in Ecology and the Environmentpoints to surprising similarities among these disparate animals. As top predators, both wolves and sharks impact their prey and other species in similar ways.

By examining interactions between sharks and their prey, dugongs, in Australia, researchers found a number of commonalities between how wolves impacted elk when reintroduced to Yellowstone National Park in the US.

Top predators do not only keep prey populations in check, but, according to a number of studies, establish an ‘ecology of fear’ in their prey, whereby the prey’s day-to-day behavior is constantly affected by the predator’s presence, i.e. shark and wolf. These impacts go far beyond predator and prey: research has shown that the presence of such predators can significantly impact a whole trove of species from plants to other animals.

Top: a wolf in Yellowstone National Park. Photo courtesy of Yellowstone National Park. Bottom: a tiger shark. Photo by N. Hammerschlag, courtesy of Oregon State University.

“For too long we’ve looked at ecosystem functions on land and in the oceans as if they were completely separate,” said co-author William Ripple with the Department of Forest Ecosystems at Society at Ohio State University in a press release. “We’re now finding that there are many more similarities between marine and terrestrial ecosystems than we’ve realized. We need to better understand these commonalities, and from them learn how interactions on land may be a predictor of what we will see in the oceans, and vice versa.”

Past research has shown that the reintroduction of wolves in Yellowstone National Park reined in elk populations and kept elk wary and nervous, changing their feeding patterns. This change in the elk’s behavior lead to what is known by ecologists as a ‘trophic cascade’, whereby adding wolves to the environment spread ripples down throughout the entire food chain. Many local plants—long devastated by elk overgrazing—were suddenly returning.

“The removal of top predators from landscapes allows, via reduced predation and predation risk, unimpeded foraging by large herbivores such as elk and deer,” explained Dr. Robert Beschta, to for a previous story. “Heavy utilization of plants by these animals, over time, can greatly alter the composition of plant communities and thus impact other animals that are dependent upon these plants as part of their life cycles.”

With the wolves return, trees grew more abundantly, which heralded a population explosion of another mammal in Yellowstone National Park: the beaver.

Sharks, like wolves, have similar impacts according to Ripple’s study. Where sharks are abundant, dugongs—large mammalian herbivores—are forced by the ecology of fear to move their grazing areas just like elk. This allows seagrass meadows to recover, providing particular habitat for a host of marine biodiversity, both plant and animal.

The authors say their study should warrant more discussion between marine and terrestrial ecologists in the surprising similarities above and below water.

Oceana: Shark Myths vs. Facts

Confused about sharks? We’re here to dispel some of the biggest myths about sharks:

1. Myth: Sharks are hungry man eaters looking for any chance to attack.

Fact: Sharks are not hunting humans. Most “attacks” on humans are mistakes due to poor water visibility or are inquisitive bites. This is why there are so many more bites than fatalities.

2. MythSharks are all the same.

Fact: Shark species are incredibly diverse with very different sizes, shapes, habitats, diets and behaviors. There are approximately 500 shark species, but only three (white, tiger and bull) are responsible for the majority of all bites.

 3. Myth: All sharks are voracious predators.

Fact: Basking sharks and whale sharks, the two largest species of sharks, are filter feeders that feed on fish eggs and other tiny organisms.

4. Myth: The only good shark is a dead shark.

Fact: Sharks play a vital role in keeping marine ecosystems balanced and healthy. Additionally, sharks help coastal economies through ecotourism. Many people are willing to pay large sums of money for the opportunity to dive with sharks.

5. Myth: If a shark attack has not occurred, it means they do not live in that area.

Fact: Sharks inhabit all of the world’s oceans – from inshore, coastal waters to the open, deep-blue sea – and some can even be found in freshwater rivers and lakes.

6. Myth: Sharks have walnut-sized brains.

Fact: Sharks can exhibit complex social behavior and some species can communicate with body language, live in groups and even hunt in packs. Sharks and rays have some of the largest brains among all fish, with brain-to-body ratios similar to birds and mammals.

7. Myth: All sharks must swim constantly.

Fact: While most sharks do need to swim continuously in order to pass water over their gills and breathe, some sharks are able to actively pump water over their gills while resting on the sea floor.

8. Myth: Shark fins grow back if they are cut off.

Fact: A finned shark thrown overboard will drown, bleed to death or be eaten by other sharks.

9. Myth: Shark fins are flavorsome, nutritious and offer medicinal properties.

Fact: Shark fins offer no flavor or nutritional value. In fact, as top predators, sharks accumulate contaminants from their prey, such as mercury, which has serious health effects even at low doses.

10. Myth: Sharks have no predators.

Fact: The greatest threat to sharks is HUMANS. Each year, tens of millions of sharks are killed for their fins. We are disrupting the ocean ecosystem by killing too many sharks.


Seven National Wildlife Photo Contest Shark Pictures

Although as an editor for National Wildlife magazine I’m accustomed to seeing some of the world’s best nature photography, I never cease to be amazed by the quality of work that participants enter in the annual National Wildlife Photo Contest. Excellent shots even of species that until recently were rarely photographed show up in the contest every year, such as the following pictures of great white sharks and whale sharks.

great white shark, National Wildlife Photo Contest, NWF, Federation

One of the world’s most widely recognized predators, a great white shark cruises the waters off Mexico.

A Top Sea Predator

The white shark is perhaps the ocean’s most widely recognized predator, but it is still a creature experts know little about. However, new research is unlocking some of the mysteries of white shark behavior.

A growing body of evidence suggests that the world’s white shark population is broken into three units, one centered off South Africa, another off New Zealand, and a third, the northeastern Pacific population, that ranges between California and Hawaii.

white shark, national wildlife photo contest, NWF, federation

A great white shark breaks the surface off South Africa, a prime feeding ground where white sharks prey on seals and sea lions.

Studies conducted during the past decade show that white sharks in the northeastern Pacific Ocean have been isolated from other sharks populations for tens of thousands of years (as a species, great whites date back about 60 million years, and sharks as a group about 450 million). From late summer to early winter these sharks patrol four distinct hunting areas off California and migrate to spend the rest of the year in the open Pacific midway between California and Hawaii, an area biologists call the shark café, on the assumption that the sharks are eating there. However, at this time no one knows for sure what the sharks do in the café. The region may be a mass breeding site, or it may be where females give birth—the site of birthing areas is still a mystery.

A Killing Machine?

Studies off New Zealand indicate that white sharks are not born killers. The jaws of young sharks less than nine feet long are not strong enough for attacking large prey. Biologists working off California have found that the white shark’s diet changes with age, the animals often shifting from fish to mammals as they mature, but even that pattern is flexible—individual sharks tend to specialize in particular types of prey from a selection that includes seals, sea lions, dolphins, fish and squid.

Studies off South Africa and California reveal that sharks seek deeper waters when hunting. The dark upper body of the shark blends in with darker waters and ocean floors in coastal areas, allowing the hunter to lurk in spots frequented by seals and seal lions.

white shark, National Wildlife Photo Contest, Federation, NWF

A white shark plies the clear waters off Isla Guadalupe, Mexico. The dark upper body and white underbelly help the shark conceal itself from prey.

White sharks generally look for a seal silhouetted against the sky and attack by swimming straight up, hitting the luckless prey with such speed that a two-ton, twenty-foot shark may burst completely out of the water, its quarry locked in its jaws.

great white shark, nationla wildlife photo contest, nwf, federation

A white shark rockets from False Bay, South Africa. Hunting sharks move deep in the water and look for a seal or sea lion sihouetted against the surface. When they find one, they attack so fast that they fling themselves from the sea.

However, if a seal survives the initial attack with little or no damage, odds are it can use its greater agility to escape.

white shark, south africa, national wildlife photo contest

A hunting great white shark crashes back into the sea at False Bay, South Africa.

The Shark-Human Connection

Although great whites are coastal hunters, attacks on humans are relatively rare. In 2012, about seventy people were attacked by sharks of all kinds worldwide, with seven fatalities. About sixty percent of these attacks were on people lying on surfboards with hands and feet in the water—from the water below, they would resemble a seal. Often, after a first attack on a surfer, white sharks seem to realize their error and move on without a second attack.

Most sharks are harmless to humans. About half of the worlds’ approximately 360 shark species are less than 3 feet long; only 4 percent exceed 12 feet, and three of those feed on plankton, including the world’s largest, the whale shark—which at 30 feet long and about 5 tons is the largest animal in the world that isn’t a whale (the smallest shark is the pygmy ribbontail catshark, which grows to about 6 inches long).


whale shark, national wildlife photo contest, federation, NWF

A whale shark glides through the sea off Darwin Island in the Galapagos. Despite a mouth that might be 5 feet wide, this largest of shark species feeds on tiny things, such as fish eggs.

Humans pose a greater danger to sharks than sharks do to humans. About 30 million to 70 million sharks are killed annually by humans, both as untargeted species taken by the commercial fishing industry and as targets for trade in fins for soup, a luxury item in Asia that can price fins at up to $50 a pound. As a result, great whites as well as other species are steeply declining, some as much as 90 percent in the past two decades. Biologists fear that sharks will be past the point of recovery if better management is not initiated soon.

Loss of sharks can have far reaching ecological and economic effects. Destruction of sharks in recent years along the U.S. Atlantic coast allowed cow-nosed rays to stage a population explosion; heavy feeding by the rays later caused a collapse in bay scallop fisheries.

whale shark, largest shark species, largest fish species, national wildlife photo contest

National Wildlife Photo Contest entrant Gary Moore was boating off Kona, Hawaii, when this whale shark came up to the vessel and followed it for 5 or 10 minutes. Whale sharks are among the species harmless to humans.


Sharkwater, the truth will surface

“An eye-opening film…visually stunning… this movie will change the way you see our oceans.” – Bonnie Laufer, Tribute Magazine

For filmmaker Rob Stewart, exploring sharks began as an underwater adventure. What it turned into was a beautiful and dangerous life journey into the balance of life on earth.

Driven by passion fed from a lifelong fascination with sharks, Stewart debunks historical stereotypes and media depictions of sharks as bloodthirsty, man-eating monsters and reveals the reality of sharks as pillars in the evolution of the seas.

Filmed in visually stunning, high definition video, Sharkwater takes you into the most shark rich waters of the world, exposing the exploitation and corruption surrounding the world’s shark populations in the marine reserves of Cocos Island, Costa Rica and the Galapagos Islands, Ecuador.


n an effort to protect sharks, Stewart teams up with renegade conservationist Paul Watson of the Sea Shepherd Conservation Society. Their unbelievable adventure together starts with a battle between the Sea Shepherd and shark poachers in Guatemala, resulting in pirate boat rammings, gunboat chases, mafia espionage, corrupt court systems and attempted murder charges, forcing them to flee for their lives.

Through it all, Stewart discovers these magnificent creatures have gone from predator to prey, and how despite surviving the earth’s history of mass extinctions, they could easily be wiped out within a few years due to human greed.

Stewart’s remarkable journey of courage and determination changes from a mission to save the world’s sharks, into a fight for his life, and that of humankind.

Genre: Documentary
Running time: 89 min.
Director: Rob Stewart
Studio: Alliance Films
Producer(s): Rob Stewart
Screenplay: Rob Stewart
Cast: Rob Stewart, Paul Watson, Dr. Erich Ritter, Susan Backlinie, Godfrey Merlin, Mark Butler, Dr. Boris Worm, William Goh, Vic Hislop, Dr. Samuel Gruber, Rex Weyler, Carlos Perez Cembrero, Patrick Moore, Lisa Anastario, Larissa Gilligan


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