1More than eighty percent of the ocean remains unmapped and unobserved, making the deep sea the least explored environment on our planet.
2Sunlight cannot penetrate beyond about one thousand metres, so most of the ocean exists in permanent, crushing, and absolute darkness.
3The pressure at the bottom of the deepest trench is roughly a thousand times greater than the pressure we experience at sea level.
4Despite these brutal conditions, life flourishes there in forms so strange that early scientists refused to believe the first photographs were real.
5Around underwater volcanic vents, entire ecosystems survive without any sunlight, drawing their energy instead from chemicals dissolved in the scalding water.
6Some deep-sea creatures produce their own light through a chemical reaction, using it to attract prey, confuse predators, or find mates.
7Every expedition to the deep returns with species that have never been described before, suggesting that millions more may still await discovery.
8These extreme environments interest biologists because they may resemble the conditions where life first began on Earth billions of years ago.
9Studying deep-sea organisms has already yielded practical benefits, including enzymes used in medical tests and compounds being examined as potential cancer treatments.
10Yet mining companies are now preparing to extract metals from the seabed before scientists have even catalogued most of the creatures living there.