The most valuable part of a shark is usually its fins, which are the principal ingredient of 'shark fin soup', a traditional Chinese delicacy, which is becoming increasingly popular as more people are able to afford it.
This wasteful practice has become common because a shark's fins are so valuable while its meat is much less so.
Sets of shark fins can sell for more than US$700 per kg. A single basking shark fin once sold for nearly US$10,000.
Other shark species important for the fin market include hammerhead, blue, mako, and dogfish sharks.
Sharks around Europe
Did you know that European waters are home to such imaginatively-named sharks as the large-eyed rabbitfish, the velvet-bellied dogfish, the cuckoo ray, the little sleeper shark and the blue pygmy skate?
European waters contain a diverse array of about 70 species of sharks, including warm-blooded and fast-moving oceanic sharks, and even the notorious great white shark.
Too many of these fascinating species, however, are increasingly under threat. One-third of European shark populations assessed are now considered Threatened under the World Conservation Union (IUCN) Red List criteria. Another 20 per cent are at immediate risk of becoming so.
Not just Jaws!
The two largest shark species - basking and whale sharks (pictured here) - can grow to more than 33 and 66 feet respectively (10m and 20m) in length. These slow-moving filter feeders live off the tiniest fish and plankton. More about sharks.
Sharks have two extra senses that help them to detect prey and avoid predators. One of these is an electrical sense that enables them to detect minute electrical currents in the water by means of small pores. Find out more.
Just who is threatening whom?
MYTH: Sharks are a threat to humans. TRUTH: Humans are the greatest threat to sharks.
Humans are not the shark's natural prey, so although incidents of sharks killing humans are well-publicised, they are extremely rare. Each year, more people are killed by dogs, deer, lightning or falling coconuts - even by vending machines - than by sharks.
But by overfishing and shark finning, humans are wiping out sharks around the world at an alarming rate. Roughly one hundred million sharks and closely related rays are killed each year in fisheries, either intentionally or as bycatch. Find out more
Vulnerable
MYTH: Sharks are ferocious beasts that can take care of themselves.
TRUTH: Their slow growth, late maturation, lengthy pregnancies and small litters make sharks among the most biologically vulnerable animals in the oceans.
Female spurdog (spiny dogfish) have one of the longest gestation periods of any animal, carrying their pups for nearly two years; females from the Northeast Pacific don't reproduce until they are 35 years old! Persistent European demand for their meat is driving serial depletion of spurdog populations around the world. Find out more.
Why conserve sharks?
Most sharks serve as top predators, at the pinnacle of the marine food pyramid, and so play a critical role in ocean ecosystems. They are an integral part of them, directly or indirectly regulating the natural balance of these ecosystems - at all levels.
And because sharks usually hunt older, weaker or sick prey, they also help to keep the prey population in good condition, as healthy and strong animals are more able to reproduce and pass on their genes.
