Here is a brief post, which has some wonderful photos, about the life in the deep sea (a very large area we still know very little about), which is damaged by a lot of human activity, including deep sea trawling and oil and gas extraction.
. . . It is widely acknowledged that deep-sea ecosystems are the most extensive on Earth, represent the largest reservoir of biomass, and host a large proportion of undiscovered biodiversity . . .
With the recent discovery of Jurassic deep-sea fossils of extant families in the Austrian Alps providing evidence of colonisation of shallow waters from the deep (Thuy et al. 2014), the deep sea should be considered a biodiversity refugium.
According to Merriam-Webster, a refugium is “an area of relatively unaltered climate that is inhabited by plants and animals during a period of continental climatic change (as a glaciation) and remains as a center of relict forms from which a new dispersion and speciation may take place after climatic readjustment,” which makes me think of something like a library, or perhaps rather a safe deposit vault of historic genetic diversity, a storehouse from which new life can yet evolve, or from which species can spread, should new areas become available to them.