A scene from the savannah What sings of Africa to a human more than its rolling golden plains? Just as tropical savannahs have become an icon of the wild on Earth, Nemo too has splendid examples. The most notable of these are the enormous plains to be found in the tropical latitudes of the continent Eriatra. In this section of our grand tour - the first of several on Nemoan ecosystems - we will be exploring this great wilderness in detail, learning of its creation, its landscape and its inhabitants.
Deep sea zones The deep sea or deep layer  is the lowest layer in the oceanexisting below Divergent hydrogen sulfide chemosynthesis thermocline and above the seabedat a depth of fathoms m or more. Little or no light penetrates this part of the ocean, and most of the organisms that live there rely for subsistence on falling organic matter produced in the photic zone.
For this reason, scientists once assumed that life would be sparse in the deep ocean, but virtually every probe has revealed that, on the contrary, life is abundant in the deep ocean.
From the time of Pliny until the late nineteenth century It took a historic expedition in the ship Challenger between and to prove Pliny wrong; its deep-sea dredges and trawls brought up living things from all depths that could be reached.
Yet even in the twentieth century scientists continued to imagine that life at great depth was insubstantial, or somehow inconsequential. The eternal dark, the almost inconceivable pressure, and the extreme cold that exist below one thousand meters were, they thought, so forbidding as to have all but extinguished life.
The reverse is in fact true Below meters lies the largest habitat on earth. If Mount Everest 8, metres were submerged there, its peak would be more than a mile beneath the surface.
It was lost at sea in It has been suggested that more is known about the Moon than the deepest parts of the ocean. Before the discovery of the undersea vents, it had been accepted that almost all life on earth obtained its energy one way or another from the sun. The new discoveries revealed groups of creatures that obtained nutrients and energy directly from thermal sources and chemical reactions associated with changes to mineral deposits.
The revolutionary discovery that life can exist under these extreme conditions changed opinions about the chances of there being life elsewhere in the universe. Scientists now speculate that Europaone of Jupiter 's moons, may be able to support life beneath its icy surface, where there is evidence  of a global ocean of liquid water.
Environmental characteristics Light Natural light does not penetrate the deep ocean, with the exception of the upper parts of the mesopelagic.
Since photosynthesis is not possible, plants cannot live in this zone. Since plants are the primary producers of almost all of earth's ecosystems, life in this area of the ocean must depend on energy sources from elsewhere. Except for the areas close to the hydrothermal vents, this energy comes from organic material drifting down from the photic zone.
The sinking organic material is composed of algal particulates, detritus, and other forms of biological waste, which is collectively referred to as marine snow. Pressure Because pressure in the ocean increases by about 1 atmosphere for every 10 meters of depth, the amount of pressure experienced by many marine organisms is extreme.
Until recent years, the scientific community lacked detailed information about the effects of pressure on most deep sea organisms because the specimens encountered arrived at the surface dead or dying and weren't observable at the pressures at which they lived.
With the advent of traps that incorporate a special pressure-maintaining chamber, undamaged larger metazoan animals have been retrieved from the deep sea in good condition. Salinity Salinity is remarkably constant throughout the deep sea, at about 35 parts per thousand.
Temperature The two areas of greatest and most rapid temperature change in the oceans are the transition zone between the surface waters and the deep waters, the thermocline, and the transition between the deep-sea floor and the hot water flows at the hydrothermal vents.Hydrogen sulfide is an energy-rich source for chemolithoautotrophic, sulfur-oxidizing bacteria, but it is also highly toxic to aerobic organisms because of its inhibition of the respiratory enzyme cytochrome c oxidase at even nanomolecular concentrations (National Research Council, Division of Medical Science, subcommittee on Hydrogen Sulfide.
hydrogen sulfide The energy in inorganic hydrogen sulfide can be transformed into glucose sugars in the process of chemosynthesis. Which of the following correctly represents the layers of the earth from the innermost to the outermost layer? Who is the father of Oceanography?
•Matthew Maury What were some of the contributions (chemosynthesis) •Mutualism-both benefit How do bacteria provide food for hydrothermal vent communities? •Bacteria oxidize the hydrogen sulfide, and are often eaten by other organisms for energy. Describe water’s chemical structure and.
Life independent of sun 3 Chemosynthesis = a type of primary production Photosynthesis uses sunlight + carbon dioxide coverts to food Chemosynthesis uses sulfur + carbon dioxide converts to food Photosynthesis reaction: CO2 + H2O + sunlight CH2O + O2 Chemosynthesis reaction: O2 + CO2 + H2O + H2S CH2O + H2SO4 where H2S is hydrogen sulfide, H2SO4.
Chemosynthesis: Some organisms such as deep ocean bacteria draw energy from hydrothermal vents and produce carbohydrates from hydrogen sulfide (H2S) gas. Consumers: 1. Consumers (heterotrophs) get their food by eating or breaking down all or parts of other organisms or their.
Organisms inhabiting methane seep sediments are exposed to stress in the form of high levels of hydrogen sulfide, which result mainly from sulfate reduction coupled to anaerobic methane oxidation. Dorvilleidae (Polychaeta) have successfully invaded this ecosystem, and multiple species in divergent genetic clades co-occur at high densities.