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Understanding Ocean Zones: Midnight Zone

The deepest, darkest regions of the ocean are found from about 2000 meters down to the sea floor. It is a realm of perpetual darkness, where even the faintest blue tendrils of sunlight cannot penetrate. It has been called the “Midnight Zone” because it is continually plunged in utter blackness, even when the brightest summer sun is perched high above the surface, there is no “daytime” here. Life that exists in the midnight zone relies indirectly on the benefits of sunlight; organisms thriving in the sunny upper layers of the sea die their eventual deaths and rain down upon the sea floor a steady flow of organic nutrients to feed the masses living at or near the bottom. The organic “rainfall” includes dead microscopic organisms, such as phytoplankton and dinoflagellates, sinking downward, fecal pellets of fish and mammals, and carcasses of larger organisms sinking down to the sea bed. Those creatures that do not feed directly on the “leftovers” raining down from above, usually prey upon those that do. Many of the creatures thriving in the deep sea have taken on fascinating, gruesome and horrifying visages and proportions, developing special adaptations to surviving in this harsh environment.

The deep sea still remains largely unexplored. The extreme hydrostatic pressure of the overlying water at depths of 2000 meters and more demand technologies that can safely withstand the cold, crushing waters of the deep. The technologies used to explore the inner space of the deep sea have only recently been developed in the last 30 years, and are just now becoming more widely available to a non-civilian community of scientific explorers. There have been many, manned “missions” in the last 30 years in various submersible crafts to get a glimpse of the mysteries that lay at the bottom of the sea, but we have only begun to scratch the surface. It is estimated that less than less than one-millionth of the sea’s darkness has been explored and seen by human eyes. It is truly a frontier in its infant stages of human discovery.

The average depth of the ocean is over two miles deep. It is estimated that of all the habitable regions on earth, including dry land and the vast oceans, that the deep sea regions make up 97% of habitable living space on the planet. If you add up all the people living today with all the other living organisms on land (plants, insects, animals, microorganisms), we account for less than one percent of all the biomass (the total mass of living organisms in a given environment) on the entire planet. Truly, the most successful habitat on earth, given the biomass it supports, is the deep sea. The bottom line is, as creepy and foreign as those bizarre deep creatures are to us, there are more of them living on this planet than us! The next zone is the trench zone....