Which sharks swim in UK seas? More than you might think.

From gentle giants to some of nature's sleekest, toothiest predators – if you go for a paddle off British shores, these are some of the species that might be in there with you.

Monday, July 13, 2020,
By Simon Ingram
An ominous silhouette close to bathers off the Cornwall coast shore signifies the presence of the sea's ...

An ominous silhouette close to bathers off the Cornwall coast shore signifies the presence of the sea's most feared creature – and, certainly in the case of this harmless basking shark, also one of the most mis-represented. In terms of sharks' relative risk to human life; every year on average more people are killed by vending machines.

 

Photograph by Victor McNulty / Alamy

WITH their flexible cartilage skeletons, noses bristling with prey-tuned senses and a physical blueprint largely unchanged since the time of the dinosaurs, sharks are a swimming showcase of the perfect predator.

What's more, they are everywhere: if there's a sea, chances are there's a shark in it. What that shark might look like covers an array of wildly different creatures, all keenly adapted to their individual environments – from the deep sea, to coral reefs, the open ocean and even the occasional river.

(Find out how you size up to sharks around the world with our interactive.)   

And while the temptation may be to think of them as creatures of more exotic locations or wilder seas, wade into British waters and there are plenty of sharks in there with you – albeit perhaps not in as great numbers as they used to be. 

However adaptable, these fish – whose skeletons and gill structures align them closely to rays – face colossal challenges to survive. Human hunting for delicacies such a shark fin soup, persecution, trophy fishing and mistaken ensnarement in fishing lines results in around 100 million shark deaths every year, placing many species on the IUCN Red List

Nevertheless, it's thought some 40 species make at least fleeting visits to British seas – with many resident year-round. 

“Britain is a good place to be a shark enthusiast,” says Yannis Papastamatiou, Assistant Professor at the Predator Ecology Conservation Lab at Florida International University and a National Geographic Explorer. “I grew up in the UK, and didn't consider it a good place – as I didn't think we had many sharks in our waters. That attitude has definitely changed.” (Yannis Papastamatiou is hosting a LIVE Q&A on Shark Awareness Day – 14th July @ 6pm. Want to learn more about sharks? Click here to watch!)

According to Papastamatiou, the secret to sharks' hundreds of millions of years of success is a difficult question to answer. “Sharks have been around a long time – maybe that's due in some ways to their relative simplicty.” he says. “It could be because in some ways they are quite like mammals, in terms of how they mate and how some of their offspring develop. Evolution finds a way – and their plan has been successful for a long time.” 

“I grew up in the UK... and didn't think we had many sharks in our waters. That attitude has definitely changed.”

Dr Yannis Papastamatiou

So where do you go to spot a British shark?

Cornwall, outstretched as it is into the mild, oceanic currents of the North Atlantic, is Britain's unofficial shark capital – both for attracting seasonal visitors of the shark kind, and plenty of tourists to document the evidence. But Devon, the west coast of Scotland and Ireland all have their own hotspots. And true to the mystique of sharks, just because nobody is there to see them doesn't mean they aren't there. But what might be there?

Here are eight contenders.

Greenland shark

One of the largest and more scientifically enigmatic sharks is this slow-moving, slow-growing denizen of the cold seas of the north Atlantic. Its distribution ranges considerably further than its geographically specific name may suggest – and it can be found in deep water off the coast of Scotland, Ireland and as far south as the northern Spanish coast

The Greenland shark isn't just found off the coast of Greenland – though it does prefer cold Arctic seas, where its slow metabolism is an asset. It also enable this shark to reach astonishing age, with some radiocarbon dating suggesting these animals can live in excess of four centuries – making them the longest-lived vertebrate ever known.

Photograph by National Geographic Image Collection

Recent research also suggests the Greenland shark (Somniosus microcephalus) may live up to an eyebrow-raising 400 years. For chronological context, this means specimens still swimming the north Atlantic today might have just missed the funeral of Shakespeare – but could still have seen the Mayflower sailing overhead.

This slow-and-steady lifestyle is thanks in part to a glacial metabolism and miserly energy expenditure, which also earns it the title of the slowest-swimming shark. But both can have their drawbacks; it's believed females may not reach sexual maturity for 150 years, meaning any dip in the species' numbers could take – literally – centuries to recover.     

Smooth hammerhead shark

Distinguished from its closest relatives by the detail of its eponymous head, or cephalofoil (the scalloped variant has indentations along the leading edge of the 'hammer') the smooth hammerhead (Sphyrna zygaena) is fond of colder waters in summer and is often found around the coast of Portugal and the Azores, making occasional visits to UK waters.

Considered one of the shark world's great travellers and often migrating in large numbers, hammerheads – including a possible great hammerhead – have been sighted by scientists off the coast of Cornwall.

The extraordinary head of the hammerhead family of sharks is packed with senses designed to detect vibrations in the water – and is shaped for sweeping the seafloor in search of concealed prey. Unlike its bigger relative the great hammerhead, the smooth hammerhead favours temperate water – making it a north Atlantic migrant that occasionally strays into UK waters. This shark was photographed off the Azores. 

Photograph by Paulo Oliveira / Alamy

These charismatic sharks are believed by scientists to be amongst the species – along with the fearsome-looking but docile sand tiger shark – that we may see more of in British waters if oceans continue to warm.   

Porbeagle shark

With a burly, spindle-shaped body, Lamna nasus is a member of the mackerel shark, or lamnidae family – a classification defined by a pointed snout, distinctive fins, and some useful evolutionary tools for their environment.

“Porbeagles are present in UK waters the whole year round,” says Richard Peirce, author of Sharks in British Seas, conservationist and former chairman of the Shark Trust. “They are cousins of the great white and mako – and all of these sharks can regulate their body temperature above that of the surrounding water.”

Smaller but similar in appearance to its mackerel shark cousin the great white, so associated is this shark with British waters it has been suggested its curious name is of Cornish origin. Wide-ranging, one specimen tagged off the coast of Ireland was later found to have crossed the Atlantic to Nova Scotia, which is where this shark was photographed.

Photograph by Doug Perrine / Alamy

This adaptation – also shared by another great white doppelgänger, the salmon shark – is called endothermy, and effectively makes these fish warm-blooded. The potential reasons why some sharks have developed such a costly mechanism for expending energy are still being researched, but a 2015 study by an international team of scientists speculated it could pay off dividends when it comes to hunting, long-distance swimming and reproduction.

“These endothermic fishes are putting a lot more energy into each unit of movement than their cold-blooded counterparts,” University of California Santa Barbara research biologist Jenn Caselle told The Current. “In fact, the estimated cost of transport is twice as high – but in return they’re getting benefits from that increased swimming speed and wider range of migration.”           

Thresher shark

Sometimes reaching over four metres in body alone and unmistakeable thanks to its long caudal fin – the top half of the tail – the thresher shark (Alopias vulpinus) uses its most dramatic physical feature as, effectively, a whip. Scientists have observed this occasionally large and elusive shark using its tail to separate fish from shoals, stunning them in the process and making them more vulnerable to being picked off.

A thresher shark in open water near the Philippines. Three variants of the species – all exhibiting the enigmatic, scythe-like tail – and all have been heavily hunted.  

Photograph by Beara Creative / Alamy

This, reports Nature, ‘might indicate that sharks are more intelligent than scientists thought.’ It's also something of an athlete, and has been observed clearing the water with leaps, or ‘breaches’, much like its cousin the great white – a predatory behaviour thought to recruit the element of surprise to surface-dwelling prey. The thresher is far from common in UK waters, but it has been known to dramatically announce its presence as such: in 2018 a large thresher shark was photographed spectacularly breaching off the coast of Devon. 

Basking shark

A summer visitor to the western coastlines of the United Kingdom, this enormous shark is hardly subtle – and if such a measure existed would comfortably be the easiest British shark to spot from the shore. Perhaps not surprisingly then, the basking shark (Cetorhinus maximuswas once hunted heavily off the coast of Scotland and Ireland, where its presence was betrayed by its habit of feeding at a leisurely pace near the surface, exposing a distinctive dorsal fin that made it fatally easy to chase down.

Divers observe two basking sharks off the coast of Mull, Scotland. Usually portrayed with their huge mouths agape, these colossal filter-feeding fish can reach eight metres in length – and are a draw to divers when cruising offshore. 

Photograph by Nature Picture Library / Alamy

Despite its intimidating size and silhouette, the basking shark is a filter feeder, using its gaping mouth and gills to sieve plankton – and like its larger, tropical counterpart the whale shark poses little threat to humans other than a fright. “The basking shark is the second largest fish in the sea and I regard it as Britain’s most noteworthy shark,” says Richard Peirce. “It is awe-inspiring when sighted.”

Shortfin mako shark

Like the porbeagle, another mackerel shark is the speedy and fearsome shortfin mako (Isurus oxyrinchus). Metallic blue and snaggle-toothed, the shortfin mako is also thought to be the fastest shark – its sub-surface darts of up to 35 mph earning it the nickname the ‘cheetah of the ocean.’ A migratory shark, it can range throughout a spectrum of water temperatures around the world, with its speed enabling it to chase down equally brisk prey such as tuna and swordfish.

(Related: Mako sharks get new protections - get the facts.)

The shortfin mako – here seen off the coast of New Zealand – is sometimes called the ‘blue pointer’, aligning it with its relative the great white, or ‘white pointer’. 

 

Photograph by Nature Picture Library / Alamy

Its qualities as a predator have also made it the target of another over the years; persecution has made both the shortfin and longfin mako endangered according to the IUCN red list. Recent protections have restricted trade – but sport fishing continues.   

Angelshark

Flattened, with a diamond-shaped body and eyes on top of its head, the angelshark (Squatina squatina) has an appearance seems to bridge the gap between sharks and their cartilaginous relatives the rays. An ambush predator, the shark – which can reach 2.5 metres in length – spends much of its time submerged in seafloor sand, waiting for prey to swim overhead. 

The bottom-dwelling angelshark is today much rarer in British waters than even a few decades ago. Heavy commercial fishing and bottom trawling have decimated the species.  

Photograph by imageBROKER / Alamy

Due to their propensity to be caught by the controversial practice of seafloor trawling, angelshark populations have been decimated by fishing as a bycatch – despite having no commercial value. Squatina squatina is listed as critically endangered by the IUCN red list, and is possibly extinct off the east coastline of the UK. A slow-growing shark which reaches reproductive age between 8-12 years, any population recovery will be slow.   

Blue shark

Sleek with huge eyes and a long snout, the blue shark (Prionace glauca) is a migratory species found worldwide. Its eponymous colouration is – like many sharks – one of its principal weapons for stealthy predation. It exhibits 'countershading', wherein its topside is a dark blue grading to an underside that is almost white. This is a camouflage trick that makes the shark seem to work with the complex light and shade of the sea to remain discreet to prey from almost every angle. 

Instantly recognisable due to its long snout and distinctive visage, the blue shark is an elegant seasonal visitor frequently found – like this individual – off the coast of Cornwall.

Photograph by Charles Hood / Alamy

Typically growing between 2 and 3 metres in length, this species, with its elongated form and dramatic fins, is often described as one of the more elegant sharks – and gives birth to a brood of up to 50 live pups. As it's currently considered near threatened, this prodigious reproduction could be an asset: it is estimated up to 20 million blue sharks are caught annually, either as bycatch, or for sharkfin soup.     

“It is nearly impossible to pick out one shark as being the most noteworthy I have observed in UK waters,” says Richard Peirce. “I once observed a 3.5 metre female blue shark who looked pregnant – and she was about as magnificent as it gets in our waters.”

So...what about Jaws?

There has been much speculation of the presence of the most notorious aquatic predator of all – the great white – off the coast of Britain. And if conditions were anything to go by, it wouldn't be that unusual.

“It’s plausible,“ says Yannis Papastamatiou, “there is no reason why they couldn’t be in UK waters, based on conditions. And they are in the Mediterranean. But to the best of my knowledge, there has never been a confirmed sighting of a live great white in British waters.” 

A great white shark (Carcharodon carcharius) off the coast of Mexico. The shark has been the target of persecution for sport fishing and due to its reputation as a menace – despite being relatively rare. The species is considered vulnerable.  

Photograph by WaterFrame / Alamy

Great whites – which can reach six metres – are rare and roaming, spread thinly around the world with well-documented hotspots South Africa, South Australia and California usually linked to large numbers of sea lions, a favoured snack.

The closest scientifically confirmed great white to British shores was a female caught in the Bay of Biscay in 1977 – 168 miles off the coast of Cornwall. But that said, the UK has conditions more comely than some of the great white's haunts, and the possibility can’t be ruled out. And while mistaken identity with the harmless basking shark are rife, a few more convincing sightings persist. 

“Having researched over 100 claimed encounters with great whites in UK waters, around 10% remain credible post investigation,” says Richard Peirce. “There is no actual proof that these were great whites – but my conviction is that it is likely, and that great whites are occasional visitors to British seas.”

Whether great whites are here or not, there should be little cause for concern. According to the Shark Trust, there have been no unprovoked shark attacks in British waters since records began in 1847. It states that ‘with so many shark species under threat we think that seeing a shark in British waters should be a cause for celebration. Not alarm.’

Sharkfest is on National Geographic Wild for two weeks from Monday 13th July. It's available to watch in the UK on Sky, Virgin Media, TalkTalk, and BT.

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