Undersea internet cables now track endangered orcas

The fiber optic cables carrying your Netflix streams sit quietly on the ocean floor, pulsing with light. But a team at the University of Washington just discovered they might do something else: listen to whales.

In October, researchers laid nearly two kilometers of cable on the seafloor in the San Juan Islands, near the Canadian border. Their experiment is simple in concept but elegant in execution. When an orca vocalizes, the sound waves vibrate the hair-thin filaments inside the cable, creating tiny distortions in the light traveling through it. By analyzing these disturbances—a technique called distributed acoustic sensing—the team can pinpoint exactly where a whale called and what it said.

Why this matters for the Southern Residents

The Salish Sea is home to 74 endangered orcas known as the Southern Residents. These whales spend most of their lives underwater, invisible to the researchers trying to protect them. Traditional underwater microphones, or hydrophones, have gaps in coverage. They're also expensive and limited in number. But fiber optic cables are everywhere—1.4 million kilometers of them crisscross the ocean floor, already carrying global data traffic.

Shima Abadi, leading the research at the University of Washington's Bothell campus, sees the potential immediately. If this trial works, the team could alert ships to slow down or change course when Southern Residents are nearby, reducing fatal collisions. Right now, vessel strikes are one of the leading causes of death for these whales.

Scientists have already proven that fiber optic cables can detect earthquakes, ships, and storms. Orca calls are just the next step. The cables are sensitive enough to pick up the distinctive acoustic signatures that distinguish one whale from another—meaning researchers could eventually track individual animals over time, understanding their movements and health in ways previously impossible.

Yuta Masuda, director of science for Allen Family Philanthropies, which contributed $1.5 million to fund the project, frames it as a proof of concept. "Our hope is that this distributed acoustic sensing trial will lead to the creation of a global monitoring network that protects endangered species like the Southern Resident orca."

Two kilometers of cable in one bay is small. But it's the first real test of whether the infrastructure we built to connect ourselves could also help us listen to the creatures we've pushed to the edge of extinction. If it works, the same cables carrying your video calls might one day help save a species.