Friday, December 02, 2016

shark attack!

Maybe you don’t want to sail out to sea because you’re afraid if the ship goes down and you find yourself bobbing about in the water a shark will sniff that bleeding cut on your finger and come scooting over for a toothier taste. Nobody likes the prospect of being eaten alive. We know it happens. We see it on the nature documentaries.

You’ve heard that shark attacks on humans are pretty rare, right? But, you know, maybe that’s because there aren’t many shipwreck victims to make a meal of.

In her book on science and war, Mary Roach investigates the military’s success in creating a sharp repellent. Soldiers at sea don’t like the idea of being eaten alive. Thinking about it causes stress. If you can supply a fella with a bottle of Shark Begone you’ll give him some peace of mind. This is war. Peace is relative. But any peace in a war!

Mary Roach says no. No such things as Shark Begone. Products that claim to be shark repellent  don’t have reliable research backing them up. There are even products that insist they repel sharks that actually attract sharks. So you want to be careful what you lather on your bobbing parts.

An article at the Smithsonian about the sharks attracted to the sinking of the USS Indianapolis in World War II builds in the fear:

Soon enough [the floating survivors] would be staving off … sharks. The animals were drawn by the sound of the explosions, the sinking of the ship and the thrashing and blood in the water. … Reports from the Indianapolis survivors indicate that the sharks tended to attack live victims close to the surface … The first night, the sharks focused on the floating dead. But the survivors’ struggles in the water only attracted more and more sharks … Of the Indianapolis’ original 1,196-man crew, only 317 remained. Estimates of the number who died from shark attacks range from a few dozen to almost 150.
Sharks!! They ate 800 sailors! 1,196 minus 317, that’s 800ish. Nobody actually knows how many living sailors managed to escape the sinking ship. How many subsequently died from exposure, dehydration, drowning? 

Mary Roach wasn’t having much luck finding stories about sharks eating sailors. 

A floating sailor [can] dispatch a curious shark by hitting it or churning the water with his legs. ([One researcher] observed that even a kick to a shark’s nose from the rear leg of a swimming rat was enough to cause ‘ … raid departure from the vicinity.’) ‘The sharks were going after dead mean,’ said a survivor quoted in a popular book about the 1945 sinking of the USS Indianapolis, an event that often comes up in discussions of military shark attacks. ‘Honestly, in the entire 110 hours I was in the water,’ recalls Navy Captain Lewis L. Haynes … ‘I did not see a man attacked by a shark.’ [emphasis in the original]

But aren’t rafts often followed by sharks? Pretty scary. Aren’t they just stalking the passengers, waiting to nab anybody who falls off? 

Mary Roach says fish like the shelter of the raft. There’s not much shade to be had out at sea so when some happens by there are those who take advantage. The sharks come to the raft to feed on the fish under the raft, not to hunt the people on it. 

Not even human blood has been shown to entice sharks. What does? What swims under rafts. Fish.  


So. Stop worrying. A shark is not going to get you. Mary Roach told me so.

source: Grunt: the curious science of humans at war by Mary Roach
2016. W.W. Norton & Co, NY

2 comments:

David Lee Ingersoll said...

I plan to avoid shark attacks by never looking like a seal.

Glenn Ingersoll said...

In the book a Navy SEAL makes a joke about sharks needing SEAL repellent.

The only other mention of a seal had to do with polar bears.

Maybe sharks attack seals because they smell like fish?