Terrible inhabitants of the seas and oceans - sharks - terrify even experienced sea wolves. In this article, we will talk about everything you need to know about sharks so that you will never be afraid of them again!
Sharks are truly amazing creatures. They appeared not only before dinosaurs, but even before trees! It is not surprising that due to the formidable appearance and ignorance of many people, the life and habits of sharks have acquired a huge number of myths.
Historical note: the first trees on the planet appeared about 350 million years ago. At that time, sharks had already existed for about 50-70 million years.
Pop culture also “helped”: the Jaws series alone convinced viewers that sharks are bloodthirsty, carnivorous killers who don’t mind biting a human.
However, most of what you may have learned about sharks from TV screens and tabloids is not true. Today, sharks are a protected species. Their populations and condition are monitored by many scientists around the world.
You may accidentally encounter a shark while cruising aboard your boat. Many divers note the shark's grace and confidence of movements, bewitching appearance. However, most people will prefer to leave the shark encounter area as quickly as possible.
What is a shark and what is it eaten with?
Sharks are a superorder of cartilaginous fish with over 500 species. They come in different sizes and colors. There are both very small sharks (the so-called pygmy shark is about 30 centimeters long) and giant sharks (whale sharks have a maximum length of up to 20 meters). Some of the most famous sharks - whites - can grow up to 6 and in rare cases up to 8 meters.
Most of the sharks have an elongated, so-called. torpedo-shaped body, which is great for developing great speed and hunting. Some shark species, especially those that live near the bottom, have a more flattened body and look like rays. Interestingly, on the outside, the scales of sharks provide reliable protection, but inside their entire skeleton consists of relatively soft cartilage.
Sharks differ not only in size, but also in their diet. The whale shark mentioned above feeds only on plankton. However, other sharks may snack on tuna, shellfish, sea lions, seals, and even sea turtles. Cannibalism, by the way, is also quite common among sharks.
Predatory fish can without a twinge of conscience be called the top of the food chain of the entire ecosystem of the seas and oceans. In addition, sharks play an important role in maintaining the balance of this very ecosystem. They protect some species from overpopulation, utilize carrion.
The Perfect Predator
There is a stereotype that sharks are imprisoned exclusively for hunting and can only hunt. However, this is not quite true. Recent studies show that sharks have a propensity not only for solving certain types of problems, but also for the manifestation of social and emotional intelligence.
Sharks are not against not only playing with each other, but also helping their relatives. In 1987, in South Africa, a group of sharks pulled a beached whale together to a deeper spot near the shore - and continued to eat.
However, sharks do have outstanding sensory organs. Their brain is very developed, the ratio of brain to body size is almost identical to that of birds and mammals. The shark brain, as the center of the nervous system, processes a huge amount of incoming information from the senses.
Hunting as a necessary condition for survival
Probably the most perfect of what nature has endowed sharks with is the sense of smell. Sharks can actually smell blood at a distance of about 1 kilometer. Interestingly, while searching for prey, predatory fish use all the tools available to them.
To begin with, the shark is looking for a common trail. The smell of blood intensifies as it approaches the target, and the shark can almost unmistakably go all this way with the help of smell. When about 250 meters remain before the victim, other “helpers” turn on - hearing, seismosensory organs and electroreception. Thanks to the system of small pores (called the lateral line) that run from snout to tail, sharks can detect changes in the surrounding water. Usually these changes are caused by the movement of the victim or other living creatures.
Thanks to the sense of smell, hearing and seismic sensory organs, the shark is able to detect prey at a great distance. In addition, the predator can find out if the prey is injured and how easy it will be to catch it by all the same sounds and vibrations that the lateral line will catch. Both hearing and lateral line also help sharks better navigate underwater and follow sea currents.
Sight is the last sense that comes into play when hunting. Being 20-30 meters from the victim, the shark begins to visually look for its future dinner. As soon as the target is identified, the shark will approach it and begin to slowly circle around. At this point, the predator is trying to determine what kind of object it is and whether it is worth attacking.
When the shark has already decided to attack, the time comes for the last check - with the help of the electroreception already mentioned above. The victim creates a bioelectric field from which the shark receives all the remaining information about the victim. When a predator is already attacking, then teeth, touch and taste come into play. Tactile receptors are located along the entire body of the shark. Thanks to them, you can determine the size of the victim (if visibility did not allow before).
An interesting fact is that sharks can doubt the suitability of the prey for consumption and sometimes "taste" it to determine exactly whether they will eat it.
What you need to know about the hunting shark?
A favorite tactic of sharks when attacking a victim is speed and lightning speed. This is the key element of surprise, which ensures the success of the attack. In principle, sharks have an average speed of 35 to 56 km/h. Some species can achieve absolutely amazing 86 km/h! Such speeds are made possible thanks to the powerful tail and caudal fin.
Despite the effectiveness of surprise attack tactics, many sharks often improvise. In addition, each species has its own special and unique hunting tactics. Some species rely on speed, while others will harass their prey with an underwater chase. Interestingly, sharks like to lull the vigilance of small fish by imperceptibly swimming up to the school and repeating their movements. Then comes the surprise attack.
Sharks usually attack their victims from behind, damaging the rear tail fin and preventing them from escaping. However, the great white shark loves the effect of surprise - it abruptly emerges straight from the depths vertically upwards, stunning its unsuspecting prey. Dolphins are especially affected by such antics. Their sonar works great in the horizontal plane, and dolphins remain vulnerable to stealthy vertical attacks.
Where do sharks live?
Most shark species live in the open sea. Most often, marine predators like places deeper and darker. They approach the coast only when they are stalking prey.
You can mainly meet a shark where the sea depth of 2-3 meters increases sharply. Often sharks can be found near coral reefs.
The habitat is wide - there are sharks in many seas. Up to 47 (!) different types of sharks live in the Mediterranean. Most of them are either very small or almost harmless species.
It is not uncommon to hear “shocking” reports from local and regional newspapers about the sighting of a “giant killer shark” somewhere in the Adriatic. Even if some representative of a large species swam on the coast of Italy, then most likely this is an isolated case.
Usually such a picture can be observed in the habitat of the last colonies of Mediterranean seals. Another option - there were flocks of tuna nearby. Every year the number of sharks in the Mediterranean decreases. Therefore, the probability of meeting even a small shark becomes less every year.
Can a shark attack a human?
We can assume that when reading the ways of hunting sharks, some readers involuntarily imagined themselves in the place of the victim and felt extremely uncomfortable. Well, fears can be understood, but we hasten to reassure you!
When compared with other animals, the number of shark attacks on humans is not only small, but extremely small. If we also count the number of attacks with a fatal outcome for a person, then the resulting number is more like a statistical error.
Today, there are several organizations that record shark attacks on people. According to the Shark Attack File, between 70 and 100 shark attacks occur worldwide every year, 5 of which are fatal. For comparison, dogs alone - cute and friendly pets of humans - kill about 200 people.
If the previous paragraph did not reassure you, then let's study the statistics a little more. Interestingly, an order of magnitude more people (hundreds) die due to farm animals (especially cattle and horses), hippos and even bees. In the United States alone, more people drown in one year than have been killed in total by shark attacks in the past two centuries.
In 2021, 137 shark attacks were recorded worldwide. Deaths 9. Remarkably, no attacks have occurred in Europe. Most of the attacks fell on Florida (USA) and Australia.
At risk are surfers (51%), swimmers (39%) and divers (4%). By the way, Croatian yachtsmen keep records of shark attacks. The last attack was more than 10 years ago, and the fatal attack was more than 50 (!) years ago.
What to do if the shark looks threatening?
If you decide to swim or explore the depths with scuba gear and see a shark, then keep calm. Sharks do not prey on humans and we are not natural prey for them. The shark will only attack when threatened.
If the shark shows an increased interest in you, then do not try to attack first and, like the hero of a Hollywood action movie, beat her. Let's say a shark appeared within your line of sight. You should assume an upright position and make as few sudden movements as possible. It would be better to turn to face her and continue to monitor her actions.
The vertical position of your body will make it clear to the shark that it is clearly not a new, previously unfamiliar type of fish. Regarding sudden movements, this is also a signal to the shark that you are not its prey trying to hide. Sharks usually attack from behind or from below, so it is recommended to turn to face them. So the predator must understand that you are not a threat.
The advice may seem strange, but do not forget that even land predators have their own special signals, thanks to which they recognize danger. The above tips should work - as a rule, the shark will limit itself to observing you from afar and swim away. But what if a marine predator is literally in front of you?
FACE - GUIDE - PUSH - MOVE
If direct contact with the shark could not be avoided, then the FACE - GUIDE - PUSH - MOVE rule should be remembered. Keep upright and watch the shark face it and rotate without losing sight of the shark. If it is literally a meter away from you, then you should gently but surely direct the shark away from you (Guide). You need to direct with your hand, touching her muzzle or the top of her head. That should be enough and the shark should swim away.
The shark has sailed away, but is moving towards you again? If there is room for maneuver, then it is worth returning to the side of the boat or to the shore (Move). If this is not enough and the predator continues to pester you, then you should neat and very gentle (Push) Touch the shark's gills. For the shark, this is the last warning - in dangerous situations, the sharks themselves usually attack the gills first. This organ is a weak and very sensitive place of the sharks themselves. The main thing is not to make sudden movements and not to beat on the gills. Such actions will provoke a shark.
These rules were developed by Erich Ritter, a Swiss shark researcher and founder of SharkSchool. He has been studying sharks for many years, their behavior and interactions.
Sharks themselves are curious and usually just want to know what kind of amazing animal is in front of them. A calm but confident demeanor will allow you to calmly survive an encounter with a shark.
How to recognize aggression?
There is a difference between mere playfulness/curiosity and outright aggression on the part of a shark. Before attacking, sharks behave in a very specific way.
To begin with, they will circle around the victim, changing speed periodically. If you are a disturber of the shark's peace in its territory, then it will try to drive you away - it will approach, circle around. Some species of sharks raise their muzzle and bare their teeth as a sign of aggression. Another sure sign of a nervous predator is the arched back and lowered pectoral fins.
All these signs indicate that the shark is irritable and ready to attack.
How to protect yourself?
A beautiful day somewhere in the warm southern waters. You have chartered a boat and want to go scuba diving. It was in the news last week that sharks can sometimes be seen in the waters here. What should be done to reduce the chance of being attacked by a predator?
There are a few simple guidelines:
- do not swim if you are bleeding or have open wounds; sharks smell blood at a great distance, this smell will serve as an excellent marker for a predator; humans are not included in the diet of sharks, but it is better not to experiment on yourself.
– do not swim near the fishermen or near the place of catching fish, as well as near schools of fish; sharks often hunt nearby, especially in the situation described above - if the place of your swimming is known for the fact that sharks live nearby, then the probability of meeting a predator is very high.
- do not swim with your back to the sun; sharks approach prey when the sun is behind them.
- do not swim at night, because sharks usually hunt in the dark, although some species are still active during the day.
– avoid restless or muddy water and estuaries; in these places, the shark is more likely to lose orientation in space and see poorly - they can take you for prey or a threat.
- do not touch the sharks yourself, do not provoke or feed them; the smell of food can provoke a shark.
What types of sharks are dangerous?
Among the variety of species, the great white, tiger and bull sharks are considered potentially dangerous. The blue shark, lemon shark and hammerhead shark are also considered quite dangerous species.
Before the cruise, you should take a closer look at the flora and fauna of the selected region. Knowing the presence of such a serious predator will help you avoid problems.
Yet the main enemy is panic. Sharks are curious but shy. By following the above simple rules, you will be able to safely get back on board the yacht.
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