You have certainly heard that sharks can smell a drop of blood from miles away. Laird once famously said that women experiencing menstrual cycle could be shark bait. You may also have heard that urine attracts sharks, too—a scary thing for the 100 percent of living surfers that pee in their wetsuits. But can they REALLY smell a tiny drop of blood from miles away? Well, these guys took the testing to a whole new level.
Using cow’s blood, fish oil, urine, and seawater, they built little pumps, stuck them on surfboards, and went to a very sharky area in the Bahamas. After an hour of testing, they got some pretty interesting results. Forty-one sharks checked out the blood board, four had a sniff at the fish oil, and none cared enough about the urine nor the seawater. But that wasn’t good enough for these researchers—no, they wanted to try human blood to see if it made a difference. Also of interest was exactly how much blood it took to get those sharks to sit up and take notice. After filling a few bags with their own blood, they rigged up the pumps again and set one on a slow drip and one on a faster drip. What they found was odd, to say the least. A total of zero sharks came to the surfboards draining that hard-earned blood into the water.
“This was by no means a perfect experiment,” said Mark Rober, “but I think it’s safe to qualitatively say that if no shark sharks came to check out 15 drops of human blood a minute in the middle of shark-infested waters, you’re probably going to be ok with a small scrape.”
So what’d these researchers come away with? Well, the same thing that most people who research sharks come away with: our fears of sharks are greatly overblown.
