phosphorous cycle in marine environment
Post on 14-Jul-2015
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Phosphorus is essential for life processes in
plants and animals.
Phosphorus is a part of the molecule that
carries energy in living cells = ATP
Phosphorous also forms the phosphate-ester
backbone of DNA and RNA.
Phosphorous is also an important consituent
in various cell components such as
phosphoproteins and phospho-lipids in cell
membrane.
How do plants and animals use phosphorus?
Plants Animals (humans)
Developing healthy seeds, root
growth, and stem strength!
Developing healthy bones (works with Ca to build bone
tissue)
Corn with a Phosphorus deficiency
The presence of phosphorous in the
environment can impact primary production
in the oceans, species distribution and
ecosystem structure.
In some marine and estuarine environment,
phosphorous acts as a limiting factor for the
primary production.
So the availability of phosphorous in the
marine environment can strongly effect the
marine carbon cycle.
The phosphorus cycle is the movement of
phosphorus from the environment to organisms
and then back to the environment.
Phosphorus is mainly found in water, soil, and
rock.
The phosphorus cycle is the SLOWEST cycle.
Eleventh most abundant element in the
Earth’s crust, comprising approximately 0.1%
by mass.
Occurs in both organic and inorganic forms.
The inorganic phosphate in minerals and
organic phosphate in rocks and soils.
Phosphorous is primarily delivered to the oceanvia continental weathering in dissolved orparticulate phase via riverine flux.
Much of the riverine particulate phosphorous isretained within continental shelves and hence isnot involved in the open ocean processes.
Atmospheric deposition through aerosols,volcanic ash and mineral dust is also importantparticularly to remote oceanic locations.
The dissolved phosphate is converted toparticulate form and then.
The dominant sink for oceanic P is depositionand burial in marine sediment in this particulateform.
A minor sink is the uptake through sea water.
In the open ocean the most of the
phosphorous remains in the dissolved form
(3*10^15) out of which maximum part is in
the deep ocean (2.9*10^15) and a small
portion (0.1*10^15) is in the surface waters.
Phosphate containing fertilizers and
phosphorous from other human activities are
washed into rivers, groundwater and
estuaries and adds a substantial amount of
anthropogenic phosphorous to the oceans.
1. Humans mine LARGE quantities of phosphate rock touse in commercial fertilizers and detergents.Phosphorous is NOT found as a gas, only as a solid inthe earth’s crust. It takes millions to hundreds ofmillions of years to replenish.
2. Phosphorous is held in the tissue of the trees andvegetation, not in the soil and as we deforest theland, we remove the ability for phosphorous toreplenish globally in ecosystems.
3. Cultural eutrophication – ad excess phosphate toaquatic ecosystems in runoff of animal wastes fromlivestock feedlots, runoff of commercial phosphatefertilizers from cropland, and discharge ofmunicipal sewage.
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