Swimming in the ocean, sharks and menstruation

Out of all of the hundreds of times (I grew up on southern California, so it might actually be thousands. Be jealous.) I’ve been to the beach and gone snorkeling/kayaking/swimming/surfing/horsing around while I’ve been on my period, I haven’t really given a second thought about sharks getting a whiff of my menstrual fluids. I’ve heard urban legends about people being attacked during their menses but I’ve always assumed it was merely a coincidence. 

I did a bit of investigating, and here’s a notable snippet I came across:

As of this writing there have been a male:female ratio of 9.2:1, or more than 90% attacks have occurred on males. This reflects a historic pattern of more males engaged in marine aquatic activities, especially those that put humans most at risk, e.g. surfing, diving, long distance swimming, warfare. It in no way can be attributed to sharks “preferring” males over females. In recent years proportionately more females are being attacked because more females are engaging themselves in riskier, formerly males-only activities. 

My advice? Don’t worry about it. Lots of women safely dive while menstruating. Although we haven’t got solid scientific data on the subject, so far we haven’t seen any obvious pattern of increased attacks on menstruating women.

Surf’s Up: The Girl’s Guide to Surfing offers these shark-safety tips [read more here]:

  • Don’t pee in your wetsuit. Urine is a sure sign of distress and sharks respond to minute concentrations of urine the way tow-truck drivers respond to 000 calls.
  • Don’t bleed into the water. If you cut yourself whilst surfing, paddle in. Sharks can detect one part blood in 25000 parts of water more than a kilometre from where you’re innocently sitting on your board waiting for your last wave in. There’s no evidence that you’re more vulnerable to shark attack during your period, though.
  • Don’t surf at dusk or in the dark; these are notorious shark feeding times.
  • Don’t surf near fishermen—where there’s fishermen, there are fish scraps and therefore sharks, because they’re natural scavengers.
  • Don’t surf near river mouths – they can get great waves but are renowned shark hangouts because of the debris and assorted matter that flows out of them from further upstream.
  • Keep your dog out of the water—dogs attract sharks by their activity in the water and at the water’s edge, and with their scent.
  • Don’t surf at night – it’s easy to find yourself still in the water trying to get that elusive last wave in but consider swallowing your pride and paddling in when it’s starting to get dark.
  • If you see a shark, don’t panic. Try to put your board between it and you, hit it on the nose (it’s been done before!) and paddle to the beach as fast as you can.
  • Don’t surf isolated beaches on cloudy/rainy days by yourself.

If you pay attention to your surroundings and the risks you’re taking while you’re in the ocean, you shouldn’t have to worry about being attacked by a shark simply because you’re on your period. 

If you’re worried about swimming during your period without using tampons or a menstrual cup, you should check out this Go Ask Alice! post

In my honest opinion, one of the best ways to beat PMS is to get outside and GO CATCH A WAVE if you can. I’m nowhere near the beach right now, so if you’re headed to the seashore sometime soon, catch one for me :)


EDIT: If you’re an oceanographer/marine biologist/icthyologist/surf connoisseur and you have any input on getting in the ocean while you’re on your period, feel free to use our ask box.