Probability of a shark attack - a statistical fallacy?

[debdiver]

Didn't Nat Geo or the Discovery Channel do a silly TV show with a countdown of the WILD animals that attack the most? Gosh, I wish I could remember exactly what that was...

http://dsc.discovery.com/convergence/sharkweek/quizzes/odds/odds.html

Hmmm... that wasn't the show I had in mind, but hey, they have a link to SHARk ATTACK MAPS!! Phew, no dot near me.

 

[Rick Inman]

An actuary is going through the security to board a plane. They find he has a bomb. When they ask why:

Actuary: "To make sure the plane is safe"
Security: "You mean you don't want to blow it up?"
Actuary: "Hardly, that's the LAST thing I'd want."
Security: "So why carry a bomb on board?"
Actuary: "Well, from your experience what are the chances of someone bringing a bomb onto a plane? About a million to one?"
Security: "That's about right."
Actuary: "Then what do you think the odds are of TWO people bringing a bomb onto the same plane? . . . ."

By that logic (if you can call it that) my best bet is to get myself a baby nurse shark and get it to bite my finger before each dive.
Ok.

 

[Kim]

Here's something else to think about!

As you are lounging on the beach contemplating wether to go in the water or not, do not do this under a coconut palm. I read an article about coconut fatalities vs shark fatalities and the coconuts were in the lead.

Never bitten by a shark.

Do play golf but never struck by lightning.

Never had a coconut on my head BUT did get a palm branch on my head once!

 

[Kim]

Also I'm reminded of an old one-liner from a comedy show in the UK (can't remember which one)

'If flying is the safest form of travel, why are there so many life insurance machines in airports?'

 

[pipedope]

Also I'm reminded of an old one-liner from a comedy show in the UK (can't remember which one)

'If flying is the safest form of travel, why are there so many life insurance machines in airports?'

Because flying is so safe. The insurance companies collect LOTS of money and rarely have to pay out.

 

[DandyDon]

From UniSciNews:


Falling Coconuts Kill More People Than Shark Attacks

"Falling coconuts kill 150 people worldwide each year, 15 times the number of fatalities attributable to sharks," said George Burgess, Director of the University of Florida's International Shark Attack File and a noted shark researcher.
"The reality is that, on the list of potential dangers encountered in aquatic recreation, sharks are right at the bottom of the list," said Burgess who was one of three scientists participating Tuesday in a National Sea Grant College Program and NOAA Fisheries sponsored press briefing on sharks and the risks of shark attacks at the National Press Club.

The event served to put the risk of shark attacks in perspective, provide resources on how to reduce the chance of a shark encounter, explain the scientific value of sharks to the coastal ecosystem and discuss fisheries management and conservation issues.

 

[IndigoBlue]

The recent history of shark attacks on the Virginia and North Carolina coasts tells me that your chances of getting attacked by a shark might just be zero unless you are swimming on the surface at dawn or dusk.

Those are the conditions for all of the attacks in recent years.

I've had sandtigers and bulls get curious, but no aggression was shown.

I believe Mr. Burke is on the right track, on this issue.

Point being, whatever the odds, wherever you are, it would be a good idea to minimize the factors against you.

Don't dive where sharks are known to be present, anyplace where the shark's favorite food is (seal and sea lion congregations, and elephant seal haul-outs especially).

Don't stay in the water after you have speared a fish. Get back to shore or the boat, and get the fish into an ice chest ASAP.

Don't attract sharks with splashing noises when you are on the surface.

Avoid long surface swims if possible. Ergo, stay close to the boat, the anchor line, and/or the bottom at all times.

Don't dive alone, always be with a group.

Take extra precautions if you are diving at night, such as staying in a protected cove for your night dive. Not all sharks are nocturnal, but many of them are, so the odds against you are higher at night.

Once you have taken all the possible precautions, then relax and don't ruin your dive by being paranoid, because the odds are then strongly in your favor that there is no chance at all you will meet a shark. Even if you wanted to.

 

[wonbok]

Didn't Nat Geo or the Discovery Channel do a silly TV show with a countdown of the WILD animals that attack the most? Gosh, I wish I could remember exactly what that was...

http://dsc.discovery.com/convergence/sharkweek/quizzes/odds/odds.html

Hmmm... that wasn't the show I had in mind, but hey, they have a link to SHARk ATTACK MAPS!! Phew, no dot near me.

That is exactly the kind of unfair statistics I was talking about.
The very first question that the Discovery quiz poses is the likelihood of dying from falling down the stairs vs. that from a shark attack. (The third question by the way was the shark attack-vs.-lightening hit statistics.)
The respective group (being the denominator in the ratio) for each case are different.
It's not apple-to-apple comparison.

Although I wouldn't want to grow unnecessary fear, I do not welcome false assurance based on skewed statistics either.
Cannot believe the Discovery Channel, one of my favorite and most trusted broadcaster, failed to be more logical.

 

[RobSue]

Thank you, this is a great point. Anyone who tries to argue that you are more likely to die from a dog/car/coconuts/vending machines than shark attacks are usually bias or forgot what they learned in their intro to statistics class. Before we use statistics to argue that you are more likely to die from other events than shark attacks, we need to establish the sample sizes of said events (which no one seems to offer when discussing this). Consider that 100 people come into close contact with sharks in one year and 1000000000 people come into close contact with dogs/cars/coconuts/vending machines in one year. If we consider further that 10 of people died from shark attacks over the year and 10000000 people were killed by a dog/car/coconuts/vending machines, then 10% of the people died from sharks and 1% of people died from dogs/cars.

 

[H2Andy]

a friend of mine was diving off Jax when he noticed a big "shadow" in the water to his left.

he turned his head and saw the biggest great white shark in creation, just feet away from him.

he panicked, of course. instinctively, he balled up into a fetal position.

the shark kept swimming. he'd known my friend was there at least 15 minutes before my friend noticed him.

lesson: I probably should wear diapers just in case.

also: we are not a shark's natural prey. we need to confuse them or lure them in for a kill (as in looking like a seal by splashing about on the surface on a surfboard. or being in the middle of a bull shark feeding pack.)