The deep sea has been documented as the largest biome on earth. Typical deep-sea ecosystems such as hydrothermal vents, cold seeps, seamounts, oceanic trenches, and whale falls, shatter our early understanding of the deep sea as a "no-go area" for life.
source https://www.lifetechnology.com/blogs/life-technology-science-news/deep-sea-organisms-research-oriented-by-deep-sea-technologies-development