Few animals instill quite the same fear as sharks. As apex predators many types of sharks are well equipped to inflict serious injury; large, fast, powerful and armed with row upon row of razor sharp teeth these fish are finely honed killing machines. Yet with around 400 shark species it is only a tiny minority that present any danger to humans. I would regard only three, possibly four, of all the species as “man-eating sharks“.
After sifting through the shark attack records held by the International Shark Attack File (ISAF) and the Global Shark Attack File (GSAF) it is clear that only a few species habitually attack people and that many of the other shark species need provoking before they will bite.
Statistically it is incredibly rare for any species of shark to attack, but when they do the results can be so horrific that it is burnt into the popular psyche. Reports of victims bitten in two or half eaten by sharks the size of a school bus are always going to be at the back of many people’s minds as they dip their toe in the ocean.
Onto the list. Unlike many lists that just rank the sharks purely on the statistics, I have looked at the potential to do damage, aggression and habitats of the sharks to decide which pose the biggest threat to humans.
10. Hammerhead Shark
The hammerhead sharks are actually a family of sharks (Sphyrnidae) which range in size from less than a metre (3ft) to over 6 metres (20ft). It is believed the strangely shaped head allows the shark better all round vision. To most observers the different species are difficult to tell apart, especially when they’re biting your foot off. It does seem likely though that it is the great hammerhead shark (Sphyrna mokarran) which are the most likely candidates. Reaching a whopping 6+ metres (20ft), weighing up to 600kg (1,300 lb) and equipped with teeth similar to those of the bull shark there is no doubt the great hammerhead could easily inflict deadly injuries on a human. It is also suggested that these may be more aggressive than other hammerhead species.
As a group the hammerheads have been involved in 34 attacks over the years, one of which was fatal. Whether this number reflects their potential danger is uncertain as they are an endangered species.
9. Blacktip Shark
The blacktip shark (Carcharhinus limbatus) is both common and widely distributed throughout the tropical /subtropical shallows of the world. It gets its name from the black tips and fringes to its fins and tail. Generally blacktips are fairly small measuring less than 5ft (1.6m), however bigger specimens can reach up to 9ft (2.8m) and weigh over 100kg (220lb). What they lack in size they make up for in energy, often being seen leaping out of the water when chasing fish.
Blacktip sharks are not generally regarded as being very dangerous to humans owing to their size. But they are frequent attackers, making up the highest percentage of shark attacks in Florida. The ISAF has 41 attacks by blacktip sharks on record, one of which was fatal.
8. Sand Tiger Shark
Many people are familiar with the sand tiger (Carcharias taurus) as the large sharks you see when visiting an aquarium. They go by a number of names including grey nurse shark, ragged-tooth shark and blue-nurse sand tiger and are found in warm waters around the world.
The sand tiger shark grows to around 3.2 metres (11ft) in length and can weigh up to 160kg (350 lbs). However, it is the ferocious looking teeth that tend to get people’s attention. There are three rows of long, sharp, pointy teeth which menacingly protrude from the sharks mouth. Despite looking terrifying, the teeth are designed for grasping small slippery prey such as fish and squid.
Sand tiger sharks probably have a worse reputation than they deserve. The fact they are called ‘tigers’ and frequently roam the surfline putting them into contact with humans does not help their cause. In reality they are not tigers at all and relatively docile. That said they have been known to attack and they have been responsible for two deaths. Many of the attacks seem to have involved spear-fishing where the shark has gone for the catch. There have also been a couple of incidents with people bitten in aquariums.
7. Blue shark
Another member of the requiem shark family, the Blue Shark (Prionace glauca) is one of the most widespread and common sharks. It can be found as far north as Norway and as far south as Chile, yet being a deep water species it rarely come into contact with people. This streamlined shark is capable of bursts of speed which it uses for chasing down its prey of squid and fish. The largest specimens recorded are over 12 ft (3.8m), but there have been unconfirmed reports of up to 21 feet.
In the wild the blue shark has few natural predators although it is said killer whales will take them. Larger sharks may also prey on small blue sharks, this was illustrated in 1969 at Sea World in San Diego where captive blue sharks were mixed in with bull sharks. Suffice to say the bull sharks thrived…
In terms of danger the odds a firmly stacked in humans favour. Between 10 and 20 million sharks are killed a year through fishing. On the other hand the blue shark is considered potentially dangerous and has been responsible for fatal attacks. Some were the result of the shark being landed in a fishing boat but others occurred on shipwrecked sailors in the open ocean. The blue shark is known to circle swimmers and divers for up to 15 minutes and it may be more inclined to take a bit in such situations.
6. Bronze Whaler Shark
The bronze whaler or copper shark (Carcharhinus brachyurus) gets its name from its colouring and the fact that this and other sharks would congregate at the sites of whale kills in the days of whaling. It is common in war, but not tropical waters around the world where it spends its time in shallow bays, harbours and estuary mouths. The species is at its most prominent during the annual sardine run in South Africa where it will gorge on the fish in groups exhibiting feeding frenzy behaviour.
The bronze whaler is a large shark reaching over 10ft (3m) in length and weighing around 675 lbs (300kg). It is a fast powerful swimmer equipped with long serrated teeth. With its size and dentition the whaler does pose a threat to humans and has been implicated in quite a few attacks. It isn’t generally aggressive towards humans but it has been known to harass spear fishermen. There have also been a number of unprovoked attacks on swimmers and surfers along the east coast of Australia including being implicated in at least two attacks that proved fatal.