The Deep Sea Ecosystem

The Deep Sea Ecosystem



Each species on our planet plays a role in the healthy functioning of natural ecosystems, on which humans depend.( - William H. Schlesinger)

The deep sea currently remains largely unexplored due to barometric pressure, extreme

temperatures and the "absence" of light. For the longest time people believed that very little life

existed in this environment. But since then research has demonstrated that a significant amount

of biodiversity exists in the deep sea. The disphotic zone is also known as the twilight zone is the

lowest boundary, which temperatures vary from -1 - 4 C. The deep sea has an adequate amount

of oxygen; it is because cold water can dissolve more oxygen than warm water. These

“thermoline currents “can travel around the globe ,and there is a significant amount of oxygen for

life because there is  not enough biomass to use it all up. Due to the deep

sea being so dark photosynthesis cannot occur  because the sun light can only go as far as 100-

200 meters .instead of photosynthesis in the deep part of the ocean there is something called

chemosynthesis that occurs.

 Chemosynthesis is the conversion of one or more carbon molecules

and nutrients into organic matter using the oxidation of inorganic molecules or methane as a

source of energy, rather than sunlight (as in photosynthesis). Nearly every life form in the ocean

 depend on photosynthesis, phytoplankton and any other marine plants to produce carbon dioxide

into organic carbon, which is a very important building block of organic

matter, the reason we

depend on phytoplankton and other marine plants is because  in the deep sea there is not a lot

of sunlight to produce photosynthesis. Phytoplankton is microscopic organisms that live in

watery environments both salty and fresh.

Since the average depth of the ocean is about 4300 meters, the photic zone represents only a tiny

 fraction of the ocean's total volume. But due to its capacity for photosynthesis, the photic zone

has the greatest biodiversity and biomass of all oceanic zones. The three main energy and

nutrients sources for the deep sea are; chemosynthesis, hydrothermal vents, and marine snow.

Hydrothermal vents are a fissure in the ocean floor especially at or near a mid-ocean ridge from

which mineral rich super heated water is issued.

“Pressure is the greatest envirmental factor acting on the deep sea organisms.

, although most of the deep sea is under pressure between 200 and 600 atm,

The range of pressure is from 20 to 1,000 atm. Pressure exhibits a great role in the distribution

Of deep sea organisms.”(Wikipedia)

In conclusion, the essential biotic factors in the deep sea are chemosynthesis, phytoplankton and the pressure.