Shark Week 2019: We Have an Answer to If Sharks Can Actually Smell a Drop of Blood in the Water

Shark Week 2019 is still young, but Mark Rober and the Discovery Channel are already testing some major myths about the ocean predators — including if a shark can sense a drop of blood in the water from more than a mile away.

Rober, a NASA engineer who has since taken his scientific prowess to YouTube, kicked things off Sunday on the Discovery Go app with a video chronicling his experiment to see if people are justified to be nervous about a little scrape heading into the ocean. While Rober acknowledged the Mythbusters team tried to take this on years ago, he admitted, "I think even they would have admit, at least in this case, the methodology was less than scientifically rigorous."

As the first stage of his experiment, Rober and marine biologist Luke Tipple ventured into the middle of the ocean off the coast of the Bahamas, when they pumped sea water (a control), urine, fish oil and cow's blood into the water at a controlled rate from surfboards anchored off the boat.

Rober and Tipple were shocked to see none of the sharks seemed interested in any of the liquids for much of the experiment, but with just about 15 minutes left in the experiment, sharks began to catch on to the trail of blood being left. The results? While no sharks were interested in the control or urine, four were interested in the fish oil and a whopping 41 were spotted checking out the blood.

Taking the experiment a step further, Rober and some of his partners on board volunteered their own blood to see if human blood had the same effect on the sharks. With one surfboard pumping human blood out quickly and another slowly, everyone on board was fascinated to find that zero sharks were interested in any of the human blood being pumped into the water.

"So 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 going to be OK with a small scrape," Rober concluded. "I mean, there certainly won't be some kind of feeding frenzy with a single drop of blood from all sharks within a mile."

Shark Week continues all week on Discovery. Check out the full schedule here.


Photo credit: JOSEPH PREZIOSO/AFP/Getty Images