Shark Week Fact vs. Fiction: Former NASA Engineer Tests if Sharks Can Smell A Drop of Blood in Ocean

Mark Rober, a former NASA engineer turned YouTuber, commemorated Shark Week by testing to see if sharks could smell a drop of blood in the water.

Shark Week, an annual Discovery Channel event dedicated to the ocean predator, commenced on Sunday and Rober was included in the premiere date with a special original program for the Discovery Go application. By Monday afternoon, the video, which was also posted on YouTube, had over 14 million views.

First, Rober pumped different liquids, seawater, fish oil, urine and cow's blood, into the ocean water of the Bahamas, just to make sure that sharks actually preferred the smell of blood. At first, none of the liquids attracted mass amounts of attention, but about 20 minutes in, sharks started to notice the blood.

With about 15 minutes left of the one-hour mark, sharks started swimming along the trail of blood and then turning away when they realized it only led them to a surfboard. In the end, four sharks checked out the fish oil, none were interested in the urine or seawater and 41 were interested in the blood.

shark week blood water sharks mark rober
White shark warning signs greet visitors to Cape Cod's beaches on Thursday in Wellfleet, Massachusetts. On Sunday, Discovery GO users watched former NASA engineer Mark Rober conduct experiments to see if sharks could smell a drop of blood in the ocean. Andrew Lichtenstein/Corbis/Getty

Rober took the experiment a step further and along with himself, recruited a few others on the boat to donate their own blood just to see if sharks liked human blood as much as cow's blood.

One surfboard pumped seawater into the ocean to act as a control, one pumped the human blood quickly and one pumped it slowly. After another hour, no sharks were interested in the seawater or the surfboard depositing blood slowly. Not a single shark was interested in the surfboard pumping blood quickly into the water, either.

"This is by no means a perfect experiment, but I think it's safe to qualitatively say that if no sharks came to check out 15 drops of human blood a minute in the middle of shark-infested waters, you're probably gonna be okay with a small scrape," Rober said.

Rober isn't the first person to experiment with sharks and blood and more than 10 years earlier, MythBusters conducted a test. In the test, Adam Savage and Jamie Hyneman first released fish blood and found the sharks were attracted to it.

However, when they pricked a finger and released human blood in the water, they found the lemon sharks had little interest.

So, it seems the cliché shark myth that the ocean predator can smell a drop of blood in an Olympic size swimming pool, has repeatedly proven to be just that, a myth.