The deep ocean, covering 66% of Earth, is the planet’s most extensive and least explored ecosystem. It plays a vital role in oxygen generation and climate regulation, and provides resources like food and medicines.
The deep seabed and the ocean are closely connected, intertwining their benefits. Yet, a study by Ocean Discovery League reveals that only a tiny fraction of the deep seafloor has been mapped, leaving much of this vast underwater world a mystery.
Despite decades of exploration, humans have observed less than 0.001% of the deep seafloor, making it one of Earth’s most mysterious realms. Research into this vast ecosystem remains limited, with visual surveys concentrated in only a few regions.
Visual imaging and mapping and sampling are crucial for studying the deep ocean. Dr. Katy Croff Bell of Ocean Discovery League warns that our lack of knowledge poses a significant challenge for science and policy with rising threats like climate change and deep-sea mining. A deeper understanding is needed to guide conservation and resource management decisions.
This study, using data from 44,000 deep-sea dives across 120 countries since 1958, is the most comprehensive estimate of deep-sea observations to date, yet it highlights significant gaps in exploration. Even if estimates are off by a factor of ten, less than 0.01% of the seafloor has visual records. Nearly 30% of documented observations occurred before 1980, often producing only low-resolution black-and-white imagery.
Remarkably, over 65% of deep-sea observations come from just three nations—the U.S., Japan, and New Zealand. Due to the high costs, five countries (the U.S., Japan, New Zealand, France, and Germany) account for 97% of submergence data, shaping global perceptions of the deep ocean from a minimal sample.
The study also highlights gaps in seafloor habitat research—canyons and ridges have been well studied, while vast regions like abyssal plains and seamounts remain largely unexplored.
This study highlights the urgent need for a global push to explore the deep ocean, ensuring scientific research and conservation truly reflect its vast and hidden depths. If scientists made assumptions about land ecosystems based on just 0.001% of Earth’s surface, it would be like judging all life on land using only an area the size of Houston, Texas.
To close this knowledge gap, researchers urge expanding deep-sea exploration and leveraging new, cost-effective technologies to increase access, especially for low- and middle-income nations. Advances in smaller, affordable tools present an opportunity to broaden participation and make ocean research more inclusive.
Dr. Ian Miller of the National Geographic Society emphasizes that deep-sea exploration, driven by scientists and local communities, is key to understanding and protecting Earth’s largest ecosystem. Dr. Bell’s work aims to equip coastal communities with cutting-edge technology for a more representative analysis of the deep ocean.
The study serves as a wake-up call for better global ocean research and conservation strategies, encouraging collaboration to unlock the mysteries of our planet’s last frontier.
Journal Reference:
- Katherine Bell, Kristen Johannes, Brian Kennedy, and Susan Poulton. How little we’ve seen: A visual coverage estimate of the deep seafloor. Science Advances. DOI: 10.1126/sciadv.adp8602
