Do sharks prefer the smell of mammal or fish blood?
In the centuries that humans have feared sharks, a plethora of myths have sprung up about them. The most notable one that everyone has heard is how a shark can smell and be drawn by a single drop of blood in the ocean from miles and miles away. We must admit, the thinking behind this is terrifying and has been the subject of many a bad sci-fi movie about the ocean's greatest predators.
However, as scientists have come to understand more about sharks, some of the traditional fears of these animals are being re-examined under a bigger magnifying glass. Often, it turns out there is no validity to some of the myths about sharks at all.
Enter YouTuber Mark Rober. This guy is a former NASA engineer who now does crazy scientific experiments to answer some of humanity's most burning questions. In this video he comes up with a rather ingenious experiment to see which will draw more sharks, fish blood, or the blood of a mammal?
This experiment was incredibly simple with those surfboards, but the results seem to speak for themselves. The surfboard that was dropping fish blood into the ocean got the interest of sharks 134 times. Compare that to only eight approaches to the board that was dripping cow blood into the ocean. It just seems to serve as further proof that sharks do not intentionally seek out humans and other mammals as snacks. They are hard-wired to kill and eat fish.
This just goes to show that stuff like the Jaws movies are simply that, fiction. While attacks on humans do occur, it seems that the sharks were not actively seeking out humans to kill in most instances. This experiment proves that mammal blood does attract their attention, but it does not send them into an instant feeding frenzy like you see in the movies.
Although it was notable that during his cage dive that the sound of the banging cage door drew those sharks back in quickly for a second look once the bait bags of blood had dissipated. We are guessing his experiment for shark week next year will involve something along those lines. Thanks for the interesting video Mark and for helping shed a little more light on these mysterious ocean predators.