The sharks of the world
From a very young age you were taught to fear them and yet, today, it is urgent to defend and protect them.
Since time immemorial sharks have suffered from a reputation as bloodthirsty hunters and man-eaters! A reputation which is perpetuated by a few films and spectacular photographs.
But the reality is very different. Out of the 500 known species across the oceans, very few are in reality a danger to man! Sharks are in fact timorous and wary creatures! Each year in all the oceans less than one hundred attacks are recorded.
Often it is a case of "mistaken identity" on the part of sharks who mistake surfers, for example, with sea lions or turtles, which they do eat. Sharks are indeed efficient predators. They are at the top of the food chain and therefore play a crucial role in maintaining the balance of species’ populations in the oceans. Even if adult sharks have virtually no predators in the ocean, it is man, through his careless fishing methods, who is their greatest enemy today. It has been estimated that 100 million sharks are killed each year mainly for the culinary value of their fins.You can help to save them from this modern slaughter! How? Simply by refusing to buy any products derived from this 'shark hunt' because their disappearance would lead to a true ecological disaster and irreversible damage to the ocean’s ecosystem.
The truth about sharks
Sharks are cartilaginous fish like rays and chimaeras. They differ from bony fish in that their skeletons are composed of cartilage and they have gill slits (between 5 and 7 on each side of the head depending on the species) compared to just 1 for bony fish. There are around 500 species of shark which inhabit all the seas of the planet (except the Southern Ocean) from the surface down into the abyss. Their features, shapes and highly effective sensory organs make them top predators at the summit of the food pyramid.
The life of a shark
Sharks already swam the oceans in the Cambrian period, so they are ancient animals. Their bodies have evolved and adapted to their environment and role as predator perfectly. They have a hydrodynamic shape and powerful muscles enabling them to swim very quickly. Some sharks can reach speeds of 40 km/h (the speed of a cruise ship or ferry). They also have highly evolved sensory organs including a 6th sense enabling them to better detect their preys. Their teeth vary according to the species, depending on their diet, and they are constantly growing and being replaced. Most sharks never stop swimming and there are two reasons for this. They must swim for water to circulate through their gills (enabling them to breathe) but also because they have no swim bladder (which allows other fish to control their buoyancy).
Most sharks are predators (with a carnivorous diet consisting of fish, shellfish and marine mammals) but the two largest sharks in the world – and therefore fish in the world – the whale shark and the basking shark, feed only on plankton.
Shark reproduction can be very slow, which exacerbates the impact of overfishing. Sharks live in association with other animals through commensalism (the pilot fish scavenges waste from the shark but gives little in return), mutualism (the remora also scavenges scraps of food from the shark but in return, it rids the shark of many of its parasites) and parasitism (flatworms and copepods live on their skin).
A predator in danger
Since time immemorial sharks have suffered from a reputation as bloodthirsty hunters and man-eaters! This view has been fabricated in books and thrillers. Yes, sharks are predators, but they do not attack everything that moves. They are in fact timorous and wary creatures! Out of over 350 species, only 3 or 4 are a potential danger for man (great white shark, bull shark, tiger shark and oceanic whitetip shark).
In reality, sharks are predators which play a fundamental role in the food chain. They contribute to the good health of the oceans by eating sick or weak animals, and regulate the number of lesser predators... Currently, the intensive fishing of sharks (especially finning) is becoming a critical issue which threatens both their survival and by extension the ecological balance of the oceans. According to a 2008 UICN report, 17 % of shark species and rays are endangered, 13% are near threatened (in other words 30% of all species) and for 47%, there is insufficient information to evaluate their survival status.