ABSTRACT
It is dif‘cult for humans to understand life in the deep sea. In the previous section, we discussed the upper layer of the oceans that we all recognize from personal experience or from media presentations. The surface has sunshine, it is relatively warm, and there are familiar ‘shes. Many humans swim, boat, and scuba there. But those happy outings provide misconceptions, because the real ocean is a far different environment, almost all of the hundreds of millions of cubic feet of it. To use a pun, we have just scratched the surface of the typical ocean, because about 97% of the ocean pelagic realm is deeper than 200 m, the lowest part of the epipelagic zone. That level is the average depth at which the penetration of sunlight is so weak that phytoplankton cannot make enough food to live. However, the abyss (deep sea) is a huge biome, the largest continuous volume of habitat on Earth.
