Just a quick query for all the girls out there...should you windsurf during that 'special' week of every month? It's just, I know sharks can detect blood in the water at 1 part per million and since tampons soak up water I figure there must be some interchange between the blood and the water. What do you think? Perhaps the reason behind shark attacks at beaches is all the menstruating ladies in the water?

Forget the old myth that sharks can detect a drop of blood in a billion litres of water or whatever rot people come up with.

Think about a drop of blood in the water- the shark can't detect it until it dissolves and all the molecules spread out and a molecule reaches the shark. It would take hours for any of those molecules to make it even 100m away. Even pouring a litre in would not attract sharks immediately unless they are within a few metres.... and if you're bleeding like that go to hospital

I have heard of a study where the results showed sharks were attracted to fish blood (and other similar marine goo) but not all all to human and other primates' blood. Dunno how tru / can't be bothered googling

sausage said...

Mark,
^ totally agree with you about debunking the 1 part / million myth.
Quantum on ABC did a story where they spent some considerable time testing blood, urine and dogs in a shark tank and from memory there wasn't a noticeable change in the sharks behaviour with the blood or urine but the dog did gain some reaction. I will try to locate link.

That's where it was! I saw it too and couldn't remember where it was.

It was the dogs movement though wasn't it?

I think they were arguing that unless its fish blood, the shark doesn't see it as a link to food and just ignores it.

Mark, please stop applying logic to problems.

Funny that all these guys are reading a thread titled "girl's business".
Sticky beaks!

As to the original question, sharks can detect minute amounts of blood/ chemicals in the water.
It is something I think about. Does it stop me sailing? No.
I probably leak more blood into the water from scraping myself on the deck when I fall off.

sausage said...

Oops - might have to retract my above non-scientic based statement
Sense of smell
Like all fish, sharks can ‘smell’ proteins at tiny
concentrations of one part protein to one billion
parts water.
Sharks locate prey by comparing chemical
concentrations between their left and right nostrils.

...forget the other stuff, I can't get over the fact that a shark knows its left and right!!

........we have a problem housten

Wahts ya number a ya single??? Babe call me, calll me

Your not the first person to wonder this. Ive been diving a lot and can knock this one on the head right now. Ask a female diving instuctor if she has loads of sharks following her for 5 days a month i think that should give you your answer.

glad that you have a courage to post a thread like this. I totally agree to others said about the myth on Blood that a shark can detect..

greenleader said...

what if you f@rt while waterstarting?

I would have thought that there was a considerable chance that the change in pressure between the inside of your @rse and the outside (post f@rt) would result in a large rush of water up the anal passage.
This could then lead to the tuning of your board to be significantly out because you would suddenly weigh a couple of kilo's more ........ IMO

Thanks for all the replies. I'm glad to hear that I probably don't need to worry. See you on the water

Bondalucci said...

General rule of thumb:


"when the wind blows, you go sailing! ......period!"

love a pun!

whyner said...

There was this person who sent twenty different puns to his friends, with the hope that at least ten of the puns would make them laugh. No pun in ten did.

You got up at 5am to post that??
red thumbs all round.

That time of the month, no probs, a male shark will know you are hormoanal and not go near you in fear of his life, a female shark will be sympathetic but also "give you space". A juvinile shark may go in for inquisitive look but just yell and scream at it and it will leave in a hurry wondering what the hell it did wrong.

Mark _australia said...

Forget the old myth that sharks can detect a drop of blood in a billion litres of water or whatever rot people come up with.

Think about a drop of blood in the water- the shark can't detect it until it dissolves and all the molecules spread out and a molecule reaches the shark. It would take hours for any of those molecules to make it even 100m away. Even pouring a litre in would not attract sharks immediately unless they are within a few metres.... and if you're bleeding like that go to hospital

I have heard of a study where the results showed sharks were attracted to fish blood (and other similar marine goo) but not all all to human and other primates' blood. Dunno how tru / can't be bothered googling

Maybe it might be best if you wear a really really tight fitting wetsuit that week, so it forms a really tight seal so nothing leaks out??
So I wounder whats more of a shark attractant, peeing in your wetsuit (approx. 100 mls) or a small drop of blood?