A shark approaches a cable on the ocean floor, opens its mouth, and bites down. The footage is real, and back in 2014 it fueled one of the internet’s most peculiar tech stories: sharks might be attacking the submarine cables that global connectivity depends on. The reality turned out to be far less alarming, but also more interesting.
The shark-and-submarine-cable story in 30 seconds
- A video that went viral in 2014 showed a shark biting a submarine cable.
- The footage was actually older: the International Cable Protection Committee (ICPC) believes it likely came from a 2003 inspection.
- The cable showed no obvious external damage, and it couldn’t even be confirmed that it was a telecom cable.
- Between 2007 and 2014, no cable failure was recorded as caused by fish or shark bites.
- The real problem today remains ships and fishing activity, which cause roughly 70-80% of failures.
The story also has a bit of a digital game of telephone to it. Over the years, it has been repeated that Google recorded a shark attacking one of its cables, or that the company discovered this way that these animals threatened its infrastructure. Research published later by the ICPC adds quite a few nuances.
The organization examined the video and historical failure records after the footage’s viral reach. Its conclusion was blunt: sharks weren’t the menace to the internet that some headlines suggested.
The video was real, but the story around it got exaggerated
The footage shows what appears to be a bluntnose sixgill shark (Hexanchus griseus) approaching the cable, biting it once, and swimming away.
That much is fairly clear.
What’s a lot less certain is everything that got built up around that footage.
According to the ICPC, the original information about the recording was scarce. The organization noted in 2015 that it had apparently been filmed in 2003 during a marine inspection and later uploaded to YouTube in 2010. It was in the summer of 2014 that it went hugely viral, coinciding with the popular US TV event Shark Week.
It couldn’t even be determined with certainty what type of cable the animal was biting.
The ICPC noted it could have been a fiber-optic telecommunications cable, but it could equally have been an underwater power cable.
Inspection of the footage also showed no obvious external damage. Experts consulted by the organization considered it unlikely that a single bite would have caused internal damage.
Nor is there reliable information suggesting the shark was injured or electrocuted.
The scene was spectacular. Its consequences, apparently, were not.
Why would a shark bite a cable?
Here too, the answer isn’t fully settled.
Sharks have sensory organs called ampullae of Lorenzini, capable of detecting extremely weak electrical fields. Among other things, this ability helps them locate prey.
That trait has, for years, fed the hypothesis that certain electromagnetic fields associated with submarine cables might catch their attention.
There are also much simpler explanations tied to the animals’ general exploratory behavior.
Either way, the fact that a shark is physically capable of biting a cable doesn’t mean it does so routinely, or that it represents a statistically significant threat.
The failure records are fairly clear on this point.
Sharks have damaged cables before, but it’s extraordinarily rare
Fish bites aren’t a purely made-up legend.
The ICPC compiled historical cases and found this type of damage across different generations of submarine cables. Between 1901 and 1957, it documented at least 28 damaged cables. Between 1959 and 2006, it found around 11 cables that needed repair due to fish bites, a category that includes sharks.
In that second period, they accounted for roughly 0.5% of all recorded failures.
After that, they essentially vanished from the statistics.
| Period | Fish/shark-related incidents |
|---|---|
| 1901-1957 | At least 28 damaged cables |
| 1959-2006 | Around 11 cables needed repair |
| Share of failures through 2006 | Roughly 0.5% |
| 2007-2014 | 0 failures attributed to sharks |
Better cable designs, armoring in certain zones, and burying cables in vulnerable areas all helped cut down these incidents.
TeleGeography continues debunking the same myth today. Its data, based on ICPC records, note that between 2007 and 2014 there wasn’t a single failure attributed to fish bites, and it describes shark attacks as an extraordinarily rare cause.
So the possibility exists, but its real significance looks nothing like the popular image of a shark determined to knock a continent offline.
The real danger to cables is at the surface
There’s a pretty good paradox behind this whole story.
While the internet was worrying about the shark, the main culprits behind broken cables were sitting several meters above it.
Ships, anchors, and fishing activity cause most of the failures.
The ICPC currently estimates there are roughly 500 submarine telecommunications cable systems and about 1.8 million kilometers of infrastructure deployed around the world. These systems carry the vast majority of international data traffic.
And they break with a fair amount of regularity.
Currently, there are approximately 150-200 submarine telecommunications cable failures every year, around three per week.
That doesn’t mean the internet goes down three times a week, either.
International networks are designed with alternative routes and capacity distributed across different cables. When one fails, traffic can be rerouted while a specialized ship locates and repairs the affected section — a resilience strategy this site has covered before, for instance with Google’s route-planning around physical obstacles for its own subsea projects.
What’s interesting is what shows up when you look at the causes:
| Cause | Approximate current share |
|---|---|
| Fishing and anchors | 70-80% of failures |
| Natural hazards | Minor share |
| Abrasion | Minor share |
| Technical failures | Minor share |
| Sharks | Exceptional |
The ICPC currently attributes roughly 70-80% of incidents to accidental human activity, mainly commercial fishing and ship anchors.
Anchors alone can be especially destructive. An analysis by the organization estimates that damage caused by dragged anchors accounts for around 30% of annual incidents, equivalent to roughly 60 failures.
A ship can cause a lot more damage than any shark.
In 2008, for example, a vessel dragged its anchor for about 300 kilometers off the coast of Sicily and damaged six submarine cables.
The internet has a surprisingly physical side
The shark anecdote also works because it clashes with the image many users have of the internet.
People talk about WiFi, the cloud, streaming, or online services as if information traveled in some nearly immaterial way.
The reality is much more physical.
Much of international communications travels through optical fibers protected inside cables that cross oceans over thousands of kilometers. Near coastlines, where human activity and risk are higher, cables may have extra protection or be buried under the seabed.
Farther from land, they generally just rest directly on the seafloor.
Their reliability also depends on something users almost never see: redundancy.
Major operators spread capacity across different systems precisely so that a single fiber break doesn’t necessarily mean cutting off service to millions of people. TeleGeography explains that this strategy keeps networks running while the affected cable is repaired.
That’s why there’s a huge difference between cutting a cable and “breaking the internet.”
The global network is made up of hundreds of interconnected systems. Certain regions with few available routes can suffer serious consequences when several failures happen at once, but a single break in a well-connected area can go completely unnoticed by users.
The famous shark from the footage didn’t even get that far.
It took a bite, apparently failed to break anything, and swam off.
More than a decade later, it still makes headlines because it perfectly represents one of those stories where the image is too good to let the data spoil it.
The data, however, pretty clearly clears the accused: if the internet ever does go down, you’ll probably want to look at an anchor or a fishing boat before blaming a shark hungry for fiber optics.
Frequently asked questions
Can sharks break the internet’s submarine cables?
There have been historical cases of fish and shark bites damaging cables, but today they are extraordinarily rare. The ICPC recorded no failures attributable to sharks between 2007 and 2014.
What causes most submarine cable breaks?
The main causes are human and accidental. The ICPC estimates that roughly 70-80% of failures are mainly related to fishing activity and ship anchors.
How many submarine cables break each year?
The ICPC puts the current figure at approximately 150-200 annual failures of submarine telecommunications cables worldwide.
Can a submarine cable break without users losing internet access?
Yes. Operators use multiple routes and cables for redundancy. When enough alternative capacity exists, traffic can be rerouted while the affected system is repaired.
Sources:
- International Cable Protection Committee (ICPC), Sharks are not the Nemesis of the Internet—ICPC Findings, 2015.
- International Cable Protection Committee (ICPC), Damage to Submarine Cables from Dragged Anchors.
- TeleGeography, Cable Breakage: When and How Cables Go Down.
- The Threat of Damage to Submarine Cables by the Anchors of Ships Underway.
