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Glossary of Chemical Oceanography Terms
Phosphate: The different species of the nutrient phosphate found in seawater (H 3 PO 4 ,
H 2 PO 4
– , HPO 4
2– , PO 4
3– ).
Phytoplankton: Free- floating microscopic plants moving mostly in the confines of the
water column. They are responsible for the greatest amount of primary production in the sea.
PO: Used as a conservative PO 4 tracer in seawater, equal to 35[PO 4 ] meas + [O 2 ] meas .
Redfield Model: Redfield found the ratio N:O:C:P in phytoplankton was relatively constant. The model assumes that this is the same ratio needed for plants to grow and
is released to solution when they die.
Silicate: SiO 2 . A micronutrient found in the skeletal material of diatoms and radiolarians.
IX. Primary Production in the Oceans
Adenosine Diphosphate (ADP): Used in the production of ATP through a cyclical series
of enzymatic reactions.
Adenosine Triphosphate (ATP): ADP + orthophosphate (P) → ATP. The phosphorylating
power of ATP is used in the assimilation of carbon dioxide.
Adsorption: Adherence of solids, liquids, or gaseous atoms, ions, or molecules to liquid or
solid surfaces.
Algae: Green plants that utilize photosynthesis to obtain energy.
Biomass: Another term for the standing crop. The amount of cells or phytoplankton in a
given amount of seawater (10 6 cells/ cm 3 ).
Chlorophyll: A principal pigment found in many plants and used in photosynthesis to
absorb photons of light.
Chromatophores: Cells that contain the photosynthetic pigments.
Compensation Depth: The depth at which the amount of photosynthesis equals the
amount of respiration (AOU = 0).
Exponential Death Phase: The phase when cells die at an exponential rate.
Exponential Growth Phase: The growth phase of an organism in which the number of
cells (N) increases in an exponential manner, ln(N/ N 0 ) = k t, where N 0 is the initial
number of cells, and k is a constant dependent on the organism and conditions
of growth.
Extracellular Products: Metabolites formed outside the cell; 30% are often not retained
when filtering seawater to measure the uptake of carbon dioxide.
Lag Phase: Delay of the growth of an organism; thought to be due to a lack of balance in
the enzymatic reactions in the cell caused by growth promoters.
Light Intensity: The amount of light reaching the surface of the oceans. The amount is
controlled by the altitude of the sun, the cloud cover, the wavelength of radiation,
absorption, and scattering.
Light Saturation: The point at which the photosynthetic rate does not increase with an
increased light intensity. After this point, inhibition of growth occurs because of
high light levels.
Micronutrients: Trace elements that marine phytoplankton requires for growth. The most
important are nitrogen, phosphorous, and silicate.
Microplankton: Phytoplankton ranging in size between 50 and 100 μm.
Nanoplankton: Phytoplankton ranging in size between 10 and 50 μm.
Glossary of Chemical Oceanography Terms
Phosphate: The different species of the nutrient phosphate found in seawater (H 3 PO 4 ,
H 2 PO 4
– , HPO 4
2– , PO 4
3– ).
Phytoplankton: Free- floating microscopic plants moving mostly in the confines of the
water column. They are responsible for the greatest amount of primary production in the sea.
PO: Used as a conservative PO 4 tracer in seawater, equal to 35[PO 4 ] meas + [O 2 ] meas .
Redfield Model: Redfield found the ratio N:O:C:P in phytoplankton was relatively constant. The model assumes that this is the same ratio needed for plants to grow and
is released to solution when they die.
Silicate: SiO 2 . A micronutrient found in the skeletal material of diatoms and radiolarians.
IX. Primary Production in the Oceans
Adenosine Diphosphate (ADP): Used in the production of ATP through a cyclical series
of enzymatic reactions.
Adenosine Triphosphate (ATP): ADP + orthophosphate (P) → ATP. The phosphorylating
power of ATP is used in the assimilation of carbon dioxide.
Adsorption: Adherence of solids, liquids, or gaseous atoms, ions, or molecules to liquid or
solid surfaces.
Algae: Green plants that utilize photosynthesis to obtain energy.
Biomass: Another term for the standing crop. The amount of cells or phytoplankton in a
given amount of seawater (10 6 cells/ cm 3 ).
Chlorophyll: A principal pigment found in many plants and used in photosynthesis to
absorb photons of light.
Chromatophores: Cells that contain the photosynthetic pigments.
Compensation Depth: The depth at which the amount of photosynthesis equals the
amount of respiration (AOU = 0).
Exponential Death Phase: The phase when cells die at an exponential rate.
Exponential Growth Phase: The growth phase of an organism in which the number of
cells (N) increases in an exponential manner, ln(N/ N 0 ) = k t, where N 0 is the initial
number of cells, and k is a constant dependent on the organism and conditions
of growth.
Extracellular Products: Metabolites formed outside the cell; 30% are often not retained
when filtering seawater to measure the uptake of carbon dioxide.
Lag Phase: Delay of the growth of an organism; thought to be due to a lack of balance in
the enzymatic reactions in the cell caused by growth promoters.
Light Intensity: The amount of light reaching the surface of the oceans. The amount is
controlled by the altitude of the sun, the cloud cover, the wavelength of radiation,
absorption, and scattering.
Light Saturation: The point at which the photosynthetic rate does not increase with an
increased light intensity. After this point, inhibition of growth occurs because of
high light levels.
Micronutrients: Trace elements that marine phytoplankton requires for growth. The most
important are nitrogen, phosphorous, and silicate.
Microplankton: Phytoplankton ranging in size between 50 and 100 μm.
Nanoplankton: Phytoplankton ranging in size between 10 and 50 μm.