A former NASA engineer braved shark infested waters to finally uncover if these ‘ruthless killers’ prefer the taste of human or fish blood.
Now a YouTuber, Mark Rober setup the gruesome experiment by placing human blood and that from a fish on two modified surfboards.
The liquids were pumped into the ocean over the course of an hour while Rober and his team stood by counting the number of visits to each board.
Using a drone, Rober and his team calculated the fish blood board was approached 134 times by the sharks, making it the winner.
Rober began this journey by traveling on a private jet to Bermuda, where he met a friend who helped him whip up a five gallon smoothie of 20 dead fish.
Although human blood was used, the team collected cow blood in order to ensure there was enough for the study – as it was both impossible and somewhat illegal to obtain five gallons.
Three surfboards were used during the experiment: one was mammal blood, another fish and the last was seawater to ensure it was not just the boards getting their attention.
Each surfboard was fitted with a pumping system that released blood slowly into the water over the course of one hour.
Following the countdown, Rober and his team used an aerial drone to count how many times each of the surfboards were approached by a shark.
Activity in the water was pretty calm for the first 20 minutes, but then Rober saw the first hit on the mammal board.
‘Pretty soon thereafter, things started heating up for the fish blood smoothie board,’ Rober said.
In total, the mammal blood board was approached eight times and no sharks approached the seawater control board.
The fish blood board was approached 134 times and Rober notes that this strongly suggests that the sharks had a preference for the fish blood.
‘The main takeaway for me from this experience is that sharks have been on this planet longer than the dinosaurs, or even trees have,’ Rober said in the video.
‘So they’ve had 400 million years of evolution to develop these instincts that are rewarded for smelling fish blood.’
‘Humans and cows will be an extremely rare delicacy so it makes sense that it’s just not hardwired into their brains.
This is the second attempt Rober has done in a bid to uncover the answer.
‘One of the limitations to last year’s test was that the boards might have been too close to the boat,’ Rober said.
‘So it’s possible some of the sharks actually smelled the blood but didn’t investigate it because they were just waiting for a handout from the boat.’
‘So this time, we basically placed the boards in the middle of the frickin’ ocean, super far away from the boat so it wouldn’t be a confounding variable.’