Sharks like this one off the coast of French Polynesia can give beach-goers a scare if they get too close to the shore.
Photograph by David Doubilet, National Geographic
Published July 4, 2013
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"Shark Attacks Rise Worldwide: Risk Assessment and Aquinas' Criteria For Sin"
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Would you go swimming where there's recently been a shark attack? It's a quandary that shark attack expert Christopher Neff, a doctoral researcher at the University of Sydney, strives to understand.
Neff has studied how the public and governments respond to shark bites in North America, Australia, and Africa. He says that with more and more people using the ocean, the way we talk about shark attacks and the methods governments use to reduce the risk of shark bites have evolved over time.
Following several shark attacks reported in the U.S. last month—off the coasts ofTexas, Hawaii, California, and South Carolina—Neff spoke to National Geographic via email about how communities around the world are responding to similar incidents, and what the thousands of Americans heading to a beach this Fourth of July weekend can do to reduce their chances of encountering a shark.
How rare are fatal shark bites? How can people heading to the beach this holiday weekend stay safe?
The International Shark Attack File has noted that, based on their 2000 data, we have a 1 in 11.5 million chance of being bitten by a shark.
My position is not that sharks are cuddly and we should be friends, but that they can be dangerous and a healthy respect for them is important.
I have a "Three What's" rule that I use when I go to the beach because I want to remind myself that I am stepping into a dynamic and wild ecosystem.
First, I ask, "What's the weather?" because swimming while it's overcast or stormy isn't a good idea. Incoming storms can cause the tide to stir up baitfish, and we want to avoid getting in the way of sharks and their prey. It's recommended that bathers stay out of the water for 24 hours after a storm, not just [until] the next morning.
Second, "What's the time of day and the environmental conditions?" We all know to avoid swimming at dawn and dusk and when the water is cloudy. But we also want to be conscious of other marine life and the seasons.
Are there seals in the area? Did a whale migration just come through? Or, is someone fishing off a pier near the beach or pouring the fish guts in the water? In all of these situations the issue is keeping our distance so sharks do not think that we are their competition [for food].
And third, "What am I doing?" Tips that can help reduce risk include not swimming alone or far away from shore. Simply put, swim in a group and stay close in.
The issue is not depth of the water. You could be waist-deep and 500 feet out standing on a reef; that does not count! In fact, the drop-offs from reefs are a great place for sharks to hang out.
Also, people shouldn't enter the water with shiny jewelry or metal because it can look like a curious thing to check out. Lastly, try not to overdo your splashing around. There are a number of stories about the way playing "shark attack" in the water attracted a shark to the area.
Towns near Cape Cod, Massachusetts, are facing an increase in thegreat white shark population. How should local governments balance spending money to prevent the relatively remote risk of a shark attack with spending money on other important issues in their communities?
Cape Cod is facing a complicated issue and the balance between costs versus fear is an interesting one. I have actually passed on three recommendations to them from my experience. The emphasis here is on individuals looking at their level of risk before they get in the water.
I suggested conveying information to the public—like signs, texts, and radio ads—that explains the ocean is not a pool. Cape Town [in Africa] has been helped a great deal by issuing citywide press releases to tell people to be cautious during the summer season.
Second, encourage people to swim close to shore. If there is an incident, the closeness to shore makes a huge difference in whether the bite is life-threatening.
Finally, information on the weather and shark behavior can help. Some excellent research out of Western Australia and Cape Town suggests that great white sharks come into shore more frequently when the water temperature is between 64ᵒF and 68ᵒF.
In Chatham, Massachusetts, the average water temperature in the summer is about 70ᵒF. So if you know that there are white sharks in the area and that they are most likely to come inshore when the water temp is somewhere near 64-70ᵒF, then each bather has information they can use in judging their level of risk.
Public education about sharks is not easy and communities around the world are still sorting out the right ways to talk with locals. Everyone uses the beach in a different way and for different reasons, so finding one message is difficult.
How have responses to shark bites changed over the years? What kind of action should a community take after shark bites like those in the U.S. in recent weeks?
Community responses have changed in a number of ways. The problem is that as more people go in the water, stay in for longer, and do more things—like kayak, surf-ski, bodyboard, or kiteboard—the chances of having shark bites increases.
[There can be] a lot of pressure on a local community that has had three, four, seven shark bites to "do something" about it.
The answer for most of these communities is having notice boards to let surfers know there are risks when going into the surf, good on-site treatment and a nearby hospital to assist with any injuries, and outreach to the public and media to tell the full story. In most cases, the outcome is not serious or not life-threatening, so conveying that is important.
You don't like to use the term "shark attack." Why?
It isn't for me or anyone to tell anyone else what to call their experience. These are deeply personal and often terrifying and life-changing events.
The point that I am trying to make is that people should know that shark "attack" as a term was invented. I gave a TED talk on the myths around shark attacks and recently wrote an academic paper with Robert Hueter from the Mote Marine Laboratory in Sarasota, Florida, on this issue.
We note that for nearly 30 years in Australia when a shark bit someone, it was called a shark "accident," and in the U.S. it wasn't believed that dangerous sharks came north of the Caribbean until 1916.
Second, not all shark attacks are created equal and there are many reported shark attacks when no one is bitten and there is no injury. For instance, our research showed that 20 percent of reported shark attacks in the Australian state of New South Wales did not involve any injury to the bather.
As a result, Dr. Hueter and I suggest four new categories that classify human-shark interactions by looking at the outcomes from the event. These include: shark sightings, when a shark swims by and no one is bitten; shark encounters, when a shark bites a surfboard or kayak, but no one is hurt; shark bites, when there is an injury that is nonfatal; and fatal shark bites, when there is a loss of life in these tragic but rare cases.
There is a media responsibility here as well. Shark attack language gets people's attention but can convey a different story than what happened.
Beaches in South Africa's Western Cape recently started using nets to keep great white sharks away from swimmers during the day. Do you think this is an effective way to reduce the frequency of shark bites?
There is no such thing as "zero-risk" when going into the ocean. It is a dynamic ecosystem and the issue around shark bites is usually related to what was going on before you stepped into the water. My motto is: We are in the way, not on the menu.
The first thing to know about the exclusion nets at Fish Hoek beach (map) in Cape Town is that they are different than anything we have in the United States, or anywhere else in the world. These are temporary nets that go out in the morning and come in at night. They are not designed to kill sharks or any other marine life. Instead, they are there to provide a nonlethal barrier.
I expect that the exclusion nets will work very well in Cape Town in conjunction with the ongoing Shark Spotter program. But before we think about adopting them in other places, there are still a few problems to consider.
Cape Town is an ideal location for these kinds of nets because it is a low-energy beach, which means the waves aren't that strong, so the net will stay put. There isn't too much kelp or seaweed to pull the nets down.
Across the world the biggest problem with nets (whether they are steel or string) is that waves crunch them and the weight of the seaweed puts them on the bottom of the ocean. In other places where culling nets are used (like Queensland, Australia, and Durban, South Africa), whales, dolphins, sea turtles, and other marine life are caught and killed in beach nets.
Exclusion nets first began in Hong Kong in the mid-1990s. The beaches are low energy and the nets stay in all the time. But because of the seaweed and number of nets, they have to be checked regularly, and this has made the program the most expensive beach safety program in the world.
For the people of Fish Hoek, I think the partnership between the exclusion nets and the Shark Spotters is a good risk reduction strategy for that beach. Personally, I think the Shark Spotter program is among the best in the world, but again, that is localized because they have clear water, good vantage points, and types of sharks that sit on top of the water, so they are easier to spot.
You surveyed beachgoers in Cape Town, South Africa, about their pride in local marine life both before and after a shark bite occurred. Did you find that people's feelings toward sharks changed after the incident?
What I found amazed me. Support and pride for sharks did not go down after the incident. We ran a statistical model on it and there was no connection between people's feelings about sharks and the shark bite incident having happened.
One thing that we did see empirically was a big drop for support of seals because a seal was involved in the shark bite. It was seen jumping around near the victim and the shark. So it appears that pride in sharks stayed the same because people blamed the seal. This finding is important because it means that if we can get real information that tells us what was going on, then we do not automatically blame the shark.
The survey also showed that government programs like the Shark Spotters did not lose confidence after the shark bite. This was important because the assumption is that politicians will be blamed, just like the mayor of Amity Island in Jaws. So elected officials overreact to protect themselves. But here, we saw a terrible event where the public didn't blame the shark or the government because there was a reasonable alternative: The seal did it!
Last year, Western Australia announced that it would allow the killing of sharks seen near swimmers. How do you feel about this policy?
It is important to note that Western Australia has not actually killed any sharks under its policy. Having said that, the Western Australian Government's preemptive shark hunt policy is, in my opinion, the least scientific, embraces the most Hollywood-esque image, and sends the worst message. No other country in the world has a similar policy.
This policy allows for the killing of vulnerable great white sharks that are swimming by a beach—even after people are out of the water—if the state authorities deem it an imminent threat.
The public is smart and way ahead of politicians and politics when it comes to sharks in the ocean. I hear all the time that it's the shark's domain and we need to respect that.
In particular, we have seen truly remarkable statements from family members who lost their loved ones after a shark fatality. They speak about the need to respect the ocean and move away from revenge hunts on sharks. That is courage.
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