Biological pump

	Email		Print
	Bookmark		Link

Biological pump

In ocean

Ocean

An ocean is a major body of Seawater, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a World Ocean that is customarily divided into several principal oceans and smaller seas....
ic biogeochemistry

Biogeochemistry

The field of biogeochemistry involves science of the chemistry, physics, geology, and biology processes and reactions that govern the composition of the natural environment , and the cycles of matter and energy that transport the Earth's chemical components in time and space....
, the biological pump is the sum of a suite of biologically-mediated processes that transport carbon

Carbon

Carbon is a chemical element with chemical symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalence?making four electrons available to form covalent bond chemical bonds....
from the surface euphotic zone to the ocean's interior.

organic carbon that forms the biological pump is transported primarily by sinking particulate material, for example dead organisms (including algal

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds....
mats) or faecal pellets. However, some carbon reaches the deep ocean as dissolved organic carbon (DOC) by physical transport processes such as downwelling

Downwelling

Downwelling is the process of accumulation and sinking of higher density material beneath lower density material, such as cold or saline water beneath warmer or fresher water or cold air beneath warm air....
rather than sinking.

Carbon reaching the deep ocean by these means is either organic carbon or particulate inorganic carbon such as calcium carbonate

Calcium carbonate

Discussion

Ask a question about 'Biological pump'

Start a new discussion about 'Biological pump'

Answer questions from other users

Full Discussion Forum

Encyclopedia

In ocean

Ocean

Biogeochemistry

Carbon

Overview

The organic carbon that forms the biological pump is transported primarily by sinking particulate material, for example dead organisms (including algal

Algae

Downwelling

Calcium carbonate

Calcium carbonate is a chemical compound with the chemical formula CalciumCarbonOxygen3. It is a common substance found as Rock in all parts of the world, and is the main component of seashells, snails, and eggshells....
(CaCO₃). The former is a component of all organisms, the latter only of calcifying organisms, for example coccolithophore

Coccolithophore

Coccolithophores are single-celled algae, protists and phytoplankton belonging to the division haptophytes. They are distinguished by special calcium carbonate plates of uncertain function called coccoliths , which are important Micropaleontology....
s, foraminiferans or pteropods. In reference to the different use of these materials in organisms, the organic

Organic chemistry

Organic chemistry is a discipline within chemistry which involves the science study of the structure, properties, composition, chemical reaction, and preparation of chemical compounds that contain carbon....
carbon portion of this transport is known as the soft tissues pump, while the inorganic

Inorganic chemistry of carbon

There is an immense number of distinct compounds that contain carbon atoms. Some sources suggest that this number is close to ten million known. However, it is possible that the number is greater....
carbon portion is known as the hard tissues pump.

In the case of organic material, remineralisation

Remineralisation

In biogeochemistry, remineralisation refers to the transformation of organic molecules to inorganic forms, typically mediated by biological activity....
(or decomposition

Decomposition

Decomposition refers to the process by which tissues of dead organisms break down into simpler forms of matter. Such a breakdown of dead organisms is essential for new growth and development of living organisms because it recycles the finite chemical constituents and frees up the limited physical space in the biome....
) processes such as bacteria

Bacteria

The Bacteria are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals....
l respiration

Cellular respiration

Cellular respiration is the set of the metabolism reactions and processes that take place in organisms' cell s to convert Energy from nutrients into adenosine triphosphate , and then release waste products....
, return the organic carbon to dissolved carbon dioxide

Carbon dioxide

Carbon dioxide is a chemical compound composed of two oxygen atoms covalent bond to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state....
. Calcium carbonate dissolves at a rate dependent upon local carbonate

Carbonate

In chemistry, a carbonate is a salt or ester of carbonic acid....
chemistry. As these processes are generally slower than synthesis processes, and because the particulate material is sinking, the biological pump transports material from the surface of the ocean to its depths.

As the biological pump plays an important role in the Earth's carbon cycle, significant effort is spent quantifying its strength. However, because they occur as a result of poorly-constrained ecological interactions usually at depth, the processes that form the biological pump are difficult to measure. A common method is to estimate primary production fuelled by nitrate

Nitrate

In inorganic chemistry, a nitrate is a salt of nitric acid with an ion composed of one nitrogen and three oxygen atoms . In organic chemistry the esters of nitric acid and various alcohols are called nitrates....
and ammonium

Ammonium

The ammonium cation is a positively electric charge polyatomic ion of the chemical formula NH4+. It has a formula weight of 18.05 and is formed by protonation of ammonia ....
as these nutrients have different sources that are related to the remineralisation of sinking material. From these it is possible to derive the so-called f-ratio

F-ratio

In oceanic biogeochemistry, the f-ratio is the fraction of total primary production fuelled by nitrate . This fraction is significant because it is assumed to be directly related to the export production of organic compound marine snow from the photic zone by the biological pump....
, a proxy for the local strength of the biological pump. Applying the results of local studies to the global scale are complicated by the role the ocean's circulation plays in different ocean regions.

The biological pump has a physico-chemical counterpart known as the solubility pump

Solubility pump

In oceanic biogeochemistry, the solubility pump is a physico-chemical process that transports carbon from the ocean's surface to its interior....
. For an overview of both pumps, see Raven & Falkowski (1999).

Anthropogenic changes

Land-use changes, the combustion

Combustion

Combustion or burning is a complex sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames, appearance of light flickering....
of fossil fuel

Fossil fuel

Fossil fuels or mineral fuels are fossil source fuels, that is, carbon or hydrocarbons found in the earth?s Crust .Fossil fuel range from volatile materials with low carbon:hydrogen ratios like methane, to liquid petroleum to nonvolatile materials composed of almost pure carbon, like anthracite coal....
s, and the production of cement

Cement

In the most general sense of the word, a cement is a binder, a substance which sets and hardens independently, and can bind other materials together....
have led to a flux of CO₂ to the atmosphere. Presently, about one third (approximately 2 Gt C y^-1) of anthropogenic emissions of CO₂ are believed to be entering the ocean. However, the biological pump is not believed to play a significant role in this flux. This is because the biological pump is primarily limited by the availability of light and nutrients, and not by carbon. This is in contrast to the situation on land, where elevated atmospheric concentrations of CO₂ may increase primary production

Primary production

Primary production is the production of organic compounds from atmospheric or aquatic carbon dioxide, principally through the process of photosynthesis, with chemosynthesis being much less important....
because land plant

Plant

Plants are Life organisms belonging to the Kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae....
s are able to improve their water-use efficiency (= decrease transpiration

Transpiration

Transpiration is the evaporation of water from the aerial parts of plants, especially leaf but also Plant stems, flowers and roots. Leaf surfaces are dotted with openings called stoma that are bordered by guard cells....
) when CO₂ is easier to obtain. However, there are still considerable uncertainties in the marine carbon cycle, and some research suggests that a link between elevated CO₂ and marine primary production exists.

However, climate change

Climate change

Climate change is any long-term significant change in the expected patterns of average weather of a specific region over an appropriately significant period of time....
may affect the biological pump in the future by warming and stratifying

Stratification (water)

Water stratification occurs when water of high and low salinity , as well as cold and warm water , forms layers that act as barriers to water mixing....
the surface ocean. It is believed that this could decrease the supply of nutrients to the euphotic zone, reducing primary production there. Also, changes in the ecological success of calcifying organisms caused by ocean acidification

Ocean acidification

Ocean acidification is the name given to the ongoing decrease in the pH of the Earth's oceans, caused by their uptake of anthropogenic carbon dioxide from the Earth's atmosphere....
may affect the biological pump by altering the strength of the hard tissues pump. This may then have a "knock-on" effect on the soft tissues pump because calcium carbonate acts to ballast sinking organic material.

Biological pump

Overview

Anthropogenic changes

See also