Discuss biological, physical and chemical controls on the ocean's biological pump.
The oceans, biological pump involves the photosynthetic fixation of carbon in the upper photic zone followed by the downward flux, through the water column, of dissolved material. The oceans absorb carbon dioxide (CO2) from the atmosphere by photosynthetic assimilation. Ultimately this assimilated carbon is transported to depth, down through the aphotic zone, as particulate matter sinks to the depths. Although a considerable amount of organic matter, which is produced is respired though metabolic activity.
Biology, physics and gravity interact to pump organic carbon into the deep sea. The processes of fixation of inorganic carbon in organic matter during photosynthesis, …show more content…
Projections based on these numbers show that by the end of this century, continued emissions could reduce ocean pH by another 0.5 units. (Ocean acidification and coral reefs, 2013) Shell-forming animals, including corals, oysters, shrimp, lobster, many planktonic organisms, and even some fish species could be gravely affected. Equally worrisome is the fact that as the oceans continue to absorb more CO2, their capacity as a carbon storehouse could diminish. That means more of the carbon dioxide we emit will remain in the atmosphere, further aggravating global climate …show more content…
Light is easily diffused through air, therefore an adequate amount of light for photosynthesis reaches all terrestrial ecosystems. On the other hand water affects the penetration and spectral characteristic of light. Light in the red end of the wavelength spectrum is filtered out sooner than light from the violet end of the spectrum. Sunlight can only penetrate to a depth of a 200 meter, this is known as the photic zone. Photosynthetic algae and plants provide most of the energy used in marine food chains. Due to photosynthesis only being possible in the photic zone and because the average depth of the oceans is about 5000 meters, most of the ocean is too deep to for photosynthesis to occur. Deep ocean ecosystems rely mainly on the input of detritus or deep sea vents. Numerous deep sea fishes have adapted by being bioluminescent to make up for the absence of light in their deep dark environment. Although limits to the depth of light penetration have important implication for life in the ocean many freshwater lakes, springs and rivers are so shallow that light availability is not an issue.
Compared to air, water has a very high specific heat (the energy required to raise the temperature of a gram of water by 1 degree centigrade). Thus, it requires more heat to change the temperature of water than it does to change temperatures in the air. Thus, terrestrial environments have much greater