For as long as humans have been exploring the oceans, reports of horrific creatures from the deep have engrossed the imagination. Of all these beasts, surely the sharks are dreaded the most. These primal fears reached their peak in 1975 with the release of Jaws, a film that kept a generation of tourists out of the water. Yet are sharks really bloodthirsty, man-eating machines – and will such fears even be relevant in years to come?
Unlike more familiar fish, such as perch, cod or eels, which have bony skeletons, sharks and their allies, the rays, belong to an ancient and primitive group of fish that possess an internal framework composed of cartilage, similar to the substance that scaffolds your ears or nose. Although cartilage does not have the robust strength of bone, it is more flexible, which when supported by seawater can allow for sleek and fast manoeuvrings through the water column. Today, the 360 or so shark species vary greatly, from the slow movements of the Greenland shark and the long serrated snouts of sawfish, to the elongated upper tail-fins of thresher sharks, and majestic oceanic giants, such as the basking and whale sharks. This anatomical diversity is reflected by a variety of feeding strategies and diets, ranging from crustaceans and molluscs, to microscopic plankton, consumed by the world’s largest fish. So where did the stereotype of giant, mindless beasts, bearing slashing jaws that are capable devouring whole human bodies derive from?
Although most sharks do not feed on large prey, there are a few species that do. These fish roam around the seas and feed on animals, such as marine mammals, by either swallowing prey whole or by biting off chunks. Although humans are not typical marine mammals, they are occasionally mistaken as a food source; additionally, some shark divers provoke sharks, which is another reason why attacks can occur. Despite the diversity of sharks, there are four principal species that are known to be involved in unprovoked, fatal shark attacks: Great-white sharks, oceanic white-tip sharks, tiger sharks and bull sharks. Nevertheless, according to the International Shark Attack File, there have been 5,213 shark attacks around the world since 1958; of these, 1,333 were fatal: a surprisingly low number, considering the abundance of human activities that interact with the sea, such as swimming, surfing, and diving. Unfortunately, it is mostly human ignorance and fear which has resulted in the shark’s formidable reputation, and with modern threats of overfishing, habitat destruction, pollution and climate change, sharks face an uncertain future. However, there is an industry that is now seriously reducing the likelihood of ever encountering a shark, regardless of your fears, views or interests.
Shark finning, a profitable and specialized fishing practice, has increased considerably over recent decades. This process involves removing the fins and tails from live sharks with a hot-metal blade, which are subsequently sold to China and Taiwan as ingredients for traditional medicine and shark-fin soup, a delicacy that can fetch high prices in top restaurants. After finning, the rest of the shark, which is usually still alive, is discarded overboard, where it dies of suffocation or predation. This practice, which targets one body part, has been outlawed by some nations; however, many countries continue to trade shark fins, which often originate from Europe and especially Spain. The demand for fins has climbed over the past few decades, mostly due to growing affluence in China, where shark-fin soup represents a status symbol of wealth and sophistication – efficient fishing technologies can now meet growing demands. Some studies estimate that 26 to 73 million sharks are removed each year for their fins, and larger species are particularly favored. Many sharks take years to reach maturity and produce few offspring, and so some species’ numbers have depleted by as much as 90%, since the 1980s. Furthermore, shark-finning is a lucrative industry; fins from most species are thought to be retailing around $400 per kg.
If the current rate of shark finning continues, it will not take too long before some species are critically endangered, or even disappear altogether. Sharks have been patrolling the world’s aquatic environments for over 400 million years, and are vital components of many marine ecosystems. The large predatory species are top carnivores in coastal and oceanic food-webs; if you remove sharks from a system, the secondary consumer populations, such as squid, octopuses, larger fish and seals, lose their natural predators and reach unsustainable numbers, which then overwhelm the primary consumers, including molluscs, crustaceans and smaller fish, until there is not enough food for the secondary consumers and the ecosystem collapses. Ecologically, sharks are vital; yet surely the sheer might, grace, and impressive beauty of sharks, and especially the larger species, should be the overriding reason why we should conserve and protect these fish for future generations. Shark finning is increasing on a global scale: If lions were being captured on the savannah grasslands, just to have their forelimbs removed and then left to die, there would be international outcry, but few people seem concerned about the fate of sharks. Hopefully we will be able to celebrate and promote the conservation of these great animals for future years, decades, and centuries to come.