How many unknown species are hiding beneath the Pacific Ocean floor?

The answer

A massive five-year deep-sea research program concluded in 2025 with a staggering finding: researchers documented nearly 800 species in the Pacific Ocean, with hundreds of previously unknown species living nearly 4,000 meters below the surface. The discovery was made in the Clarion-Clipperton Zone, a vast abyssal plain between Hawaii and Mexico that is also being targeted for deep-sea mining of polymetallic nodules. The timing of the discovery is critical - mining companies are seeking permits to harvest mineral-rich nodules from the same seafloor where these species were found. Scientists warn that mining could destroy ecosystems we've barely begun to understand, potentially causing extinctions of species not yet formally described.