Do Sharks Like The Human Blood?

There are many films and television series like Jaws that have applied the concept of sharks that are very attracted to human blood. In fact, the sharks are pictured as being able to smell blood from miles away.

As described in many Hollywood movies, sea animals did not miss the opportunity to attack when human blood scent is nearby. So the main question is do sharks really like human blood or it is a fictitious story that people tell all the time?

The Frequency of Shark Attacks

The attention that the media give to shark attacks has made it look like a frequent incidence. When in reality, the chances of shark attacks occurring on humans are very slim. Based on a global statistic, shark attack only causes as many as 10 deaths per year.

There are almost 500 species of sharks and only 3 of them were identified as the great white shark, bull shark, and tiger shark which are responsible for the most shark attacks by far. All these three species are involved in 60% of the global shark attacks where 80% of these incidents will cause death.

Does this mean the sharks are more attracted to human blood as portrayed on television or on the silver screen?

The truth is, sharks are generally not attracted to human blood but instead will detect any fluid or blood that comes out of humans. But, sharks are not capable of smelling a drop of blood from miles away as we thought.

Smell Sensory of Sharks

According to several studies, sharks are more attracted to animals' blood like fish or sea lions compared to humans. The Zoo Taronga in Australia even said that sharks might be attracted to humans due to their blood, urine or strong body smell.

With all of that being said, it is still impossible for sharks to sense fluids like blood from miles away since the blood itself will be diluted in the seawater. Claims stating that only a drop of human blood can get the attention of sharks from far away is difficult to be proved.

There are also instances where the shark will approach swimmers or divers even though blood or a strong smell is not present. Most likely that the sharks are more interested in human activities than the smells of blood.

For women who are on their period, it is also considered a fluid that can be detected by sharks. But no proof has been proclaimed stating that it is the cause of shark attacks. On top of that, the chances of the menstrual blood going into the water is very low since the pressure inside the water will temporarily stop the flow of the blood.

The Experiment of Shark's Reaction

An ex-NASA engineer, Mark Rober has conducted an experiment to answer this question. He used a pump filled with cow's blood, fish blood, and seawater on three different surfboards. 
The pump will release the fluid into the water as the surfboard moves. Roberts also monitored the number of sharks near the surfboard with the help of a drone. For one hour, he found that no fish will approach the surfboard that is only filled with seawater whereas the ones filled with cow's blood is approached by 8 sharks.

On the other hand, the surfboard that is filled with fish blood is approached by 134 sharks altogether. Despite not using human blood in his experiment, this study is good enough to show that sharks are more attracted to fish blood compared to cow blood.

Other Reasons For Shark Attacks

The smell sensory is not the only reason why shark attacks occur. It is proven that sound is the main reason that sharks will move towards a location. However, as the shark moves toward the sound, it will rely more on its vision compared to the sound.
Sharks can easily get attracted to low-frequency sound, especially in the range of 10-50 Hz. This frequency is commonly emitted by fish that are injured or fighting for its life. Based on the experiment, sharks are more sensitive to frequencies between 40 and 800 Hz. Sharks will use their side sensory organs to find their prey within a 250 meters vicinity or more.

Humans Are Not A Part Of Their Diet

As explained before, there are only specific shark species that are involved in attacks on humans. But still, their natural prey will be other wildlife like fish or sea lions. Humans are not considered a part of their diet and logically speaking, sharks do not hunt humans as part of their food.

Instead, they will attack if they feel threatened or they have mistakenly seen the human as sea lions. That means if you were doing any activities in the ocean like swimming or diving, there is only a slight chance of a shark attack happening.

Most victims however survived the shark attack unless, of course, the person experiences heavy bleeding.


Post a Comment