Sharks feed primarily on other smaller fish, but diets vary by species and by whether they live alone or in groups. For example, sharks that live in groups may prey on larger fish, harassing and biting them until they bleed to death.
But sharks are mostly solitary hunters. With poor eyesight, they use organs located at the end of their nasal appendage, which detect electric fields.
What do sharks eat?
Carnivores, sharks feed on a wide variety of prey from many different biotopes throughout the water column.
Most feed mainly on live prey, some usually attack healthy individuals (if they can catch them), others eat sick or injured animals (diseases and parasites make animals more vulnerable to shark attacks).
Others often feed on corpses.
All sharks usually hunt prey of similar size or smaller, and consume bony fish, mollusks, crustaceans, pinnipeds, cetaceans, turtles, snakes and seabirds, echinoderms, worms, sea anemones, jellyfish and other organisms.
The list even includes very small organisms such as krill and copepods. The popular belief is that sharks eat everything, which is far from the truth!
Many are opportunistic feeders, which means that they are versatile and able to use a variety of food sources, depending on availability. When their favorite prey becomes scarce, they switch to other species that are more abundant locally.
Why do sharks eat fish?
Fish is a privileged source of omega-3, some of which are essential for the development and functioning of sharks. Among oily fish, some contain more of the so-called omega-3s and are therefore particularly interesting from a nutritional point of view as they contribute to the prevention of diseases and to the development of sharks.
Fish is also a source of protein, minerals such as phosphorus, and trace elements such as iodine, zinc, copper, selenium and fluorine, but also vitamins A, D, E essential to the survival of the shark.
Can sharks eat us?
The human species is not part of the shark diet. They prefer fatter prey, which is why most of the time, a shark that attacks and bites a human being releases it and runs away. Some experts go even further and claim that sharks have a deep-seated rejection for human flesh. These shark attacks occur because they often mistake humans for their prey.
For a long time, everyone thought that sharks were some kind of giant garbage can that swallowed anything and everything, but this is not true. Sharks feed mainly on fish, they can feed on seals, small whales, dolphins when they have the opportunity. It can also be a scavenger and feed on carcasses of dead animals. Some species, such as the whale shark, only eat plankton.
Why do sharks sometimes attack humans in the water?
Before an attack can occur, there must be an encounter between a human and a shark. As pelagic fish resources are depleted in the oceans, sharks tend to move closer to the coast to find food. At the same time, water-based activities are becoming more accessible, so the number of people potentially in contact with sharks, even if the global shark population is decreasing, is increasing.
An encounter does not imply an attack! Many swimmers have come into contact with sharks without realizing it and without any other consequences. When there is an attack, the scenario is often the same. The victim is bitten on a limb and the attacker disappears. Then, either the wound inflicted is benign, or it is serious, and the danger is then linked to the time needed for the victim to return to the beach and stop the bleeding.
Depending on whether you are a swimmer, surfer or diver, some basic precautions will limit your chances of encountering a shark, which are basically extremely low.
In fact, most people who have seen sharks swimming around have fond memories of them. After the surprise, the observer understands that the shark, in the middle of the day, is very calm and just passes by, not very curious about humans.
It is therefore more a question of keeping calm, knowing that many sharks do not exceed one meter. Last but not least, seeing a shark usually means that it is not hunting, as we should not forget that this fish is the biggest predator of the seas. If you have the opportunity to see a shark, of course a small one, the recommendation would be to observe it with caution and calmness, as it might flee very quickly as soon as it notices your presence.
Why do sharks attack surfers?
Even though systems such as shark nets are in place to protect swimmers, surfers may be confronted by sharks.
Large sharks, over three meters in size, hunt prey such as sea lions or sea lions, which like to play in the waves.
Thus, attacks on surfers are most often a misunderstanding of a shark, which thinks it is hunting its favorite food.
So, as for swimmers, a shark that bites a surfer will flee immediately afterwards, realizing its mistake.