Despite the Earth's surface being largely covered by deep oceans, a new study highlights how little of the planet's largest ecosystem has been explored.
Researchers from the Ocean Discovery League, Scripps Institution of Oceanography, and Boston University calculated, using publicly available data, how much of the deep-sea floor has been visually documented.
After 67 years of deep-sea diving, humanity has only explored between 0.0006% and 0.001% of the deep ocean floor. The upper estimate corresponds to an area of 3,823 square kilometers (1,476 square miles), which is slightly larger than the U.S. state of Rhode Island or about one-tenth the size of Belgium.
The lead author of the study, deep-sea explorer Katherine Bell, and her team provided visual comparisons to help better understand these estimates. For example, one image shows the deep-sea floor overlaid on the eastern U.S., while another shows the same amount placed over Belgium.
The researchers note that we have visual records of only a tiny percentage of the deep ocean floor, despite it covering 66% of the Earth's surface. Furthermore, 30% of the observations come from black-and-white, low-resolution photographs taken before 1980.
The study's authors collected more than 43,000 records on dives deeper than 200 meters, and analyzed the historical development of deep-sea exploration, excluding private sector oil and gas exploration data.
INCREASING DEEP-SEA EXPLORATION AND GLOBAL INEQUITIES
From the 1960s to the 2010s, the number of deep-sea dives quadrupled. However, over time, these explorations have concentrated more on coastal and shallow waters. In the 1970s, nearly 60% of dives were deeper than 2,000 meters, but by 40 years later, that figure dropped to just one-quarter.
Today, five countries— the United States, Japan, New Zealand, France, and Germany— have explored 97% of the world's ocean depths.
URGENT STEPS NEEDED FOR DEEP OCEAN CONSERVATION
Bell, president and founder of the Ocean Discovery League, emphasized that "with the growing threats to the deep ocean, such as climate change and potential mining, the limited exploration of such a vast region poses significant challenges for science and policy."
To make informed decisions on resource management and conservation, she stressed the need to better understand the ecosystems and functions of the deep ocean.
Even with over 1,000 exploration platforms globally, Bell and her team predict that it would take about 100,000 years to fully visualize the entire ocean floor.
The findings of the study reveal a pressing need for a fundamental shift in global deep-ocean exploration and research.
