By Noa Bergman, Science Correspondent
JERUSALEM — Imagine trying to understand all life on Earth by studying a patch of land the size of a small city. That’s roughly the scale of what humanity knows about the deep ocean floor, according to a startling new study that reveals just how little of this vast underwater world we’ve actually seen. Less than 0.001% of the deep seafloor—covering two-thirds of our planet—has been visually documented, leaving an immense frontier almost entirely unexplored.
The research, published this week in Science Advances, was led by Dr. Katy Croff Bell, president of the Ocean Discovery League and a National Geographic explorer. Her team pored over records of some 44,000 deep-sea dives since 1958, spanning 120 countries, to estimate how much of the seafloor, deeper than 200 meters, has been captured by cameras. The result? A mere 3,800 square kilometers, about the size of Rhode Island or a tenth of Belgium’s land area. “I knew it was going to be small, but I didn’t expect it to be this small,” Bell told The Jerusalem Post. “We’ve been at this for nearly seven decades, and it’s still a drop in the bucket.”
The deep ocean is no mere backdrop—it’s the planet’s largest ecosystem, producing oxygen, regulating climate, and harboring bizarre creatures like vampire squid and microbes that thrive without sunlight. Yet, the study shows exploration has been patchy and skewed. Over 65% of all visual observations come from waters near just three countries: the United States, Japan, and New Zealand. Five nations—those three plus France and Germany—account for 97% of all dives, leaving vast regions like the Indian Ocean barely touched. “It’s like judging all forests by a few trees in California,” said Jeffrey Karson, a Syracuse University geologist not involved in the study. “The bias is glaring.”
Why so little progress? Cost is a major culprit. Sending a submersible or remotely operated vehicle to depths where sunlight fades and pressure crushes is no small feat. Exploring a single square kilometer can cost between $2 million and $20 million, Bell noted. Most dives hug coastlines or focus on “hotspots” like canyons and ridges, while huge swaths of abyssal plains and seamounts remain unseen. Nearly 30% of recorded dives happened before 1980, often yielding grainy black-and-white photos that pale beside today’s high-definition video.
The study also highlights a shift in exploration patterns. In the 1960s, nearly 60% of dives plunged deeper than 2,000 meters, but by the 2010s, only a quarter did, with efforts clustering in shallower waters near wealthy nations. High seas, beyond national jurisdictions, now see just 15% of dives, down from 50% decades ago. This narrow focus worries scientists, especially as threats like deep-sea mining and climate change loom. “We’re making big decisions about mining and conservation with barely a glimpse of what’s down there,” Bell said. “It’s like operating blind.”
Israel, with its Mediterranean and Red Sea coastlines, has a stake in this global challenge. While not a deep-sea exploration leader, Israeli researchers at institutions like the University of Haifa and the Israel Oceanographic and Limnological Research institute have studied marine ecosystems, often collaborating internationally. The study’s call for affordable, accessible technology—think smaller, cheaper submersibles and AI-driven image analysis—could open doors for smaller nations like Israel to contribute. “There’s talent everywhere, but not everyone has the tools,” Bell said, advocating for global access to low-cost platforms.
The findings have sparked buzz online, with posts on X calling the deep ocean “Earth’s last frontier” and marveling at how little we know compared to Mars’ surface. Some users urged billionaires to fund exploration rather than space ventures, echoing Karson’s point: “We’re pouring billions into other planets, but two-thirds of our own is a mystery.” At current rates, Bell’s team estimates it would take 100,000 years to visually map the entire seafloor.
Yet, hope glimmers on the horizon. Advances like machine learning, which can analyze hours of footage in minutes, and fiber-optic seabed sensors could accelerate discovery. Bell’s Ocean Discovery League is pushing to equip coastal communities worldwide with cutting-edge tools, aiming for a more inclusive exploration effort. “If we can democratize access, we’ll see the deep ocean in a whole new light,” she said.
For now, the deep sea remains a realm of shadows, home to untold species and secrets. As Ian Miller of the National Geographic Society put it, “If we want to protect our planet’s largest ecosystem, we need to see it first.” The study is a wake-up call, urging the world to dive deeper before it’s too late.
Noa Bergman is a science correspondent for Israel Mirror. She covers environmental and marine science, with a focus on Israel’s role in global research.
