Many reef fish have poisonous meat. In some all the time, in other fish only at certain periods. Poisons are present in all parts of the fish, but especially in the liver, intestines and caviar.
Dangerous, poisonous and aggressive fish, protection against aggressive fish and sharks when surviving in extreme conditions.
Fish toxins are soluble in water; they are not neutralized, no matter how much you cook. They have no taste, so a standard edibility test is useless. Birds are least susceptible to fish poison, so one should not assume that if a bird eats some fish, then it is safe for humans to eat. They also have little effect on cats, and dogs and rats are as susceptible as humans.
, which are barely visible in water, can have highly active stinging tentacles. Hydro jellyfish The Portuguese warship is a bluish jellyfish-like bubble with a small corrugated sail. Do not enter the water if you see these creatures. Their tentacles can extend very far, and they contain dangerous and painful toxins..
Aggressive fish species.
There are a number of very aggressive fish that should be avoided. It is known that a bold and curious barracuda can attack a person. At night, she can attack the light source or objects reflecting it. Sea bass, sometimes reaching a length of 1.8 meters, is another fish that you should stay away from, as well as moray eels, which have many sharp teeth and can become aggressive if disturbed. Sea snakes are poisonous and sometimes found in the open ocean. They are unlikely to bite, but avoid them anyway..
Very few shark attacks on humans are recorded annually, and an absolute minority is fatal. However, wrecked at sea are more vulnerable than coastal bathers, which are mainly statistics. Very few species of sharks are considered dangerous to humans. Six species are responsible for most cases: the great white shark, the tiger shark, the hammerhead shark, the Australian sand shark, and the two species of mako shark: mackerel and gray-blue.
The largest is the largest white, but the size is not an indicator of danger and is not related to the likelihood of an attack. A shark that is smaller than a human can nevertheless kill a swimmer. Giant or whale sharks can reach 13.3 meters in length, but they feed on plankton and are not a problem. Ocean sharks are quite capable of killing, but in the tropics their food is so plentiful that they are usually not aggressive. These sharks are usually cowardly and can be driven off with a stick, especially on the nose. However, noise and movement created can attract sharks from afar..
Sharks live and feed at considerable depths and feed most of the time near the bottom, but hungry sharks chase fish both on the surface and in shallow water. When a shark prowls in such places, it is most likely dangerous. Shark’s usual food includes fish, squid, crabs, and various other marine animals, but it looks for food that is easy to get, and usually attacks a jerked or wounded fish. Sharks can follow the ship to eat leftover food that is thrown overboard..
The most active shark eats at night, as well as at sunrise and sunset. Her small eyes have poor eyesight, and she finds prey by the smell and vibrations of the aquatic environment. She is attracted to blood from wounds, waste from the body and waste. Weak and erratic movements will attract her attention, since they can speak of a weak, wounded creature. Powerful uniform movements and loud noise scare her away. The strange appearance of a person for a shark is unfamiliar, and his clothes form forms that are incomprehensible to her. A group of people in clothes will be safer than loners.
If the shark keeps its distance, then it just shows curiosity. If she began to walk in narrowing circles and makes sharp movements, then the probability of an attack increases sharply. Sharks are not able to instantly stop or turn quickly. A good swimmer can dodge a single big shark, quickly changing direction so that the shark cannot respond to it. Not every fin that appears above the surface of the sea belongs to a shark. The tips of the wings of large slopes can protrude above the water and appear dorsal fins of a pair of sharks moving synchronously until unnatural. Dolphin fins that are harmless and likely to show more often may be visible..
What to do if a shark is hooked.
If a small shark accidentally gets on a hook, it can be pulled to the side, pulled its head out of the water and stun with a blow of some club before lifting it on board. Make sure she’s really stunned before approaching her, then finish her off and you will have shark chops. Do not try to do this with a large shark. It can harm both you and your boat. It is necessary to cut the fishing line and sacrifice part of it, as shark floundering will quickly attract its brethren.
If you do not have a life jacket or if you are not in a vehicle equipped with a repellent against sharks, for everyone who is in the water, the risk is quite high, but shark attack cannot be considered an inevitable event. Repellent may not be one hundred percent effective, but even use it only when absolutely necessary. Remember you can apply it only once. If there are sharks around, try to ensure that the body’s vital products do not fall overboard, this may attract sharks. Urinate in short series so that in between the urine can quickly dissolve in water.
Collect and dispose of feces as far as possible. If you vomit, try to hold the vomit in your mouth and swallow it again, but if this is not possible, try to keep the vomit as far away from you as possible. If you need to swim, do this with powerful measured strokes, trying to avoid schools of fish. If a group of people is in danger, then everyone should come together facing out..
In order to scare off the attacking shark, kick with your feet in front of you, and with your hands, using the soft base of your palm, push hard forward, like in rugby. Make more noise by striking the water with a folded handful of palm. Dip your head under water and scream. These measures are more effective for a group of people, but they can work even if you are alone and you were attacked by a shark. If you have a knife, be prepared to use it. Stick it as deep as possible into the shark snout or into the eyes or gills.
Actions on a raft or in a boat in the presence of sharks.
Do not catch fish when sharks are around and do not throw waste overboard (including excrement and fish tripe). Release bait hooks. Do not put your hands in water. If the shark is about to attack, hit the snout with a paddle, pole or stick. Remember a large shark can nibble a piece from a boat or raft. If there is repellent against sharks, follow the manufacturer’s instructions, but use the product only when the situation is really threatening. Repellent will quickly dissolve in water and lose effectiveness. Choose the moment of its use in the most careful way, since you can use it only once.
Based on the book Complete Survival Guide for Extreme Situations, in the Wild, on Land and at Sea.