Factor Influence the Productivity within the Marine Environment

v Factor Influence the Productivity within the Marine Environment :

The following are the factor which influenced on productivity of organic matter:

Ø  Physical Parameters:

·         Light

·         Temperature

·         Ocean currents

Ø  Chemical Parameters

·         Nutrients

·         Chemical Composition of Sea water

o   Light:

Organic matter produced in ocean by process of photosynthesis.

The spatial variation in photosynthetic production is controlled by light and nutrients

With availability of nutrients, the organic matter productivity increases with increasing light levels until a certain light level, further photosynthesis is inhibited with increasing light levels.

Organic matter is much produced in the photic zone.

Seasonal changes in the length of the day also influence biomass production, especially in mid and high latitudes.

o   Temperature:

Temperature depends on region within the earth (equator, polar).

Temperature between (150-450 C) more suitable for growth of organism to produce organic matter.

The optimal temperature for phytoplankton is up to (250 C) or more, where as diatoms and radiolarians dominates in cold water (50-150 C), especially in polar region.

o   Ocean Currents:

Ocean currents results in the highest rates of primary production in many estuarine, coastal, oceanic, or frontal environments.

 During slack tides or slow currents results in increased rates of photosynthesis and nutrient uptake.

During flood or ebb-tides or during fast current movement results in nutrients removal from more nutrient-rich underlying waters.

During the fast currents photosynthesis is decreased by a shortage of light due to increased turbidity and mixing of

the phytoplankton to deeper waters (Legendre 1981).

§  Nutrients:

Although phytoplankton produce energy from carbon and water, they still require both inorganic (phosphorous, nitrogen, silicon, iron, etc.) and organic (vitamins) nutrients for growth.

Generally, phytoplankton growth is limited by inorganic nutrients like metals (zinc, copper, iron, and manganese) and three other inorganic compounds (silicon, nitrogen, and phosphorous) are considered to be important to phytoplankton (Dawes 1998).

The nutrients is controlled by the following factors: currents, mixing of water (nutrients transported form land to sea), intense growth (which limits the nutrients).

§  Chemical Composition of Sea Water:

The important is the salinity, if salinity high no organic matter will produce, like dead sea.

> Normally, ocean is 3.5% saline by weight. If salinity reached to 5- 7%o. The ocean will characterized minimum number of specie.

The Organic Carbon Budget During Earth History

The total estimated amount of organic carbon is approximately 6.4x1015 t (5.0x1015 in sediments and 1.4x1015 in metamorphic rock as graphite; Welt, 1970).

More recent estimation by Hunt (1972) is that it is about twice high, he included all the carbon within three classes of rocks.

Most of the carbon on earth is concentrated in sedimentary rocks of the earth crust. Part of it is fixed as organic carbon, and greater part as carbonate carbon.

Only negligible portion of organic carbon in earth crust, including hydrosphere, is found in living organism and in dissolved state, the rest fixed in sediments.

It is estimated that 18% of total carbon in sedimentary rocks are organic and 82% of sedimentary carbon is bound in the form of carbonates (Schidlowski et al., 1974).

> There is a cyclic relationship between organic carbon and carbonate carbon, a simplified sketch shows the main processes and pathways of the relation.

Chemical Composition of Biomass: Phytoplanktons/Zooplanktons,Bacteria and Higher Plants

Lipids:

Mostly fats, oils and waxes, have the greatest potential to be hydrocarbon sources.

They are combinations of the fatty acids of the general formula CnH2nO2 with glycerol, C3H5(OH)3.

An important example is glyceride C17H35COOCH3 formed from the stearic acid, C17H35COOH.

Lipids, high in phosphorus and contains both sulfur and nitrogen.

Proteins:

Are giant molecules that make up the solid constituents of animal tissues and plant cells.

They are rich in carbon but contain amounts of N, S and O, about C: 50-55%, H: 7%, O: 19-24%, N: 15-19%, S: 0.3-2.4% and some amount of Phosphorus.

On hydrolysis, they form amino acids of the type RCH(NH2)COOH, e.g., amino-acetic acid or glycine, CH2(NH2)COOH, which is derived from albuminoids such as glue or gelatin.

Carbohydrates:

Are based on sugars Cn(H2O)n and their polymers (cellulose, starch, chitin). They are common in plant tissue.

Carbohydrate lack phosphorus, nitrogen and sulfur.Lignin

Is a polymer consisting of numerous aromatic rings. It is a major constituent in land plants and converts to coal through desoxygenation.

Abundances of Biomolecules