Nearly all international internet traffic travels through thin fiber optic cables laid across the ocean floor. Sharks have been known to bite these lines since the late 1980s. Yet the reality is far less dramatic than the headlines suggest. These incidents make up only a tiny share of cable damage, and modern protections have made them even rarer.
The Massive Network Beneath The Waves
Undersea cables form the invisible backbone of our connected world. About 99 percent of global data moves through these lines. They link continents and carry everything from video calls to financial transactions.
More than 1.7 million kilometers of these cables snake across the seafloor today. New systems continue to launch as demand for bandwidth grows with artificial intelligence and streaming. Without them, daily digital life would grind to a halt.
These cables sit in one of the harshest environments on Earth. They endure crushing pressure, shifting currents, and occasional encounters with marine life. Most people never think about them until something goes wrong.
A History Of Curious Shark Bites
Reports of sharks biting cables date back to the mid 1980s. The first confirmed cases involved an experimental fiber optic line near the Canary Islands. Scientists later found crocodile shark teeth embedded in the damaged sections.
Similar incidents popped up in the late 1980s and early 1990s. Media coverage often played up the drama. Videos from remotely operated vehicles even captured sharks investigating cables in real time.
Yet the numbers tell a different story. According to the International Cable Protection Committee, fish and shark bites caused less than one percent of all cable faults through 2006. From 2007 onward, no faults were definitively linked to sharks. Improved cable designs played a big role in that decline.
What Draws Sharks To These Cables
Experts still debate exactly why sharks show interest. Many point to the electromagnetic fields that cables can emit. Sharks have special sensors in their snouts that detect electricity from prey. A live cable might mimic the signals of a tasty meal.
Others suggest simple curiosity. Sharks often test unfamiliar objects with their mouths. A plastic coated cable could trigger the same response as anything else on the seafloor.
Importantly, these bites rarely cause major outages. Most happen in shallower waters where certain shark species hunt. Deeper sections see almost no activity. The sharks usually take one bite and move on after realizing it is not food.
Modern Armor Keeps The Connection Safe
Cable makers now build in multiple layers of defense. Steel wire armor and tough synthetic yarns protect against bites, anchors, and abrasion. Google added extra shielding resembling Kevlar to its trans Pacific routes years ago. Other companies follow similar practices in vulnerable areas.
Cables in shallow zones often get buried up to three meters under the seabed. This hides them from fishing gear and curious animals. In deeper water, the natural environment and cable weight provide enough protection.
Here are the main threats to undersea cables today:
- Ship anchors and fishing trawlers cause 65 to 75 percent of faults
- Natural events like earthquakes and landslides account for under 10 percent
- Equipment failure or unknown causes make up the rest
Shark bites no longer rank as a significant concern thanks to these upgrades.
Why Protecting These Lines Matters So Much
Undersea cables cost a fortune to build and maintain. Some designs run hundreds of dollars per foot. Installation requires specialized ships and crews working in remote oceans. A single fault can run into millions to repair, with global annual costs reaching high figures.
The economic stakes are enormous. These cables support trillions in daily commerce. Even brief disruptions ripple through businesses and households worldwide. Operators maintain backup routes to reroute traffic quickly when problems arise.
Repair ships stay busy year round. Industry experts estimate 150 to 200 cable faults occur globally each year. That means crews perform several fixes weekly on average. An aging fleet of repair vessels has prompted calls for major new investments to keep pace.
Meanwhile, sustainability efforts are growing. The pioneering TAT 8 cable, the first fiber optic link across the Atlantic from 1988, is now being recovered by hand near Portugal for recycling. Teams pull sections from the seabed decades after it stopped carrying traffic. Valuable materials get reused while minimizing ocean waste.
This work shows how seriously the industry takes its responsibility. As more cables launch to meet exploding data needs, protection and maintenance only grow more important.
The next time your connection slows, remember the vast infrastructure working silently below the waves. Sharks may grab the spotlight in fun stories, but human engineering keeps the system running smoothly. The real heroes are the teams designing tougher cables and responding to the more common threats like anchors and trawlers.
