Chemical Primary Production in the Ocean

MAR 510 Chemical

Oceanography

Primary production seawifs.gsfc.nasa.gov/SEAWIFS/IMAGES/SEAWIFS_GALLERY.html

Primary Production in the Ocean

A global composite of sea surface chlorophyll concentration

High-nutrient, low chlorophyll (HNLC)

Oligotrophic gyre (LNLC) Coastal Upwelling

Seasonal Phytoplankton blooms

MAR 510 Chemical

Oceanography

Primary production

Examples of the larger phytoplankton Coccolithophorid

Dinoflagellate

Diatom Diatom

MAR 510 Chemical

Oceanography

Primary production

Atmosphere

Aphotic Zone

Euphotic zone

CO2 Biological Pump

CO2

CO2

Organic Matter

Particle sinking, downward transport of DOM

OM decomposition

O2

Phytoplankton (no change in ALK

net decrease in pCO2)

Incident Light

O2

Zooplankton Bacteria N, P, Si, trace metals

N, P, Si, trace metals

Vertical mixing, advection

O2

MAR 510 Chemical

Oceanography

Primary production

Law of the Minimum - Liebig's Law

Justus von Liebig, generally credited as the "father of the fertilizer industry", formulated the law of the minimum: if one crop nutrient is missing or deficient, plant growth will be poor, even if the other elements are abundant. Liebig likens the potential of a crop to a barrel with staves of unequal length. The capacity of this barrel is limited by the length of the shortest stave (in this case, phosphorus) and can only be increased by lengthening that stave. When that stave is lengthened, another one becomes the limiting factor. For Phytoplankton 1)Light 2)Macronutrients (N, P) 3)Micronutrients (Fe, Zn)

1803-1873

MAR 510 Chemical

Oceanography

Primary production

Iz = I0 x e-kz

Behavior of Light in the Sea

1)Exponential decrease in intensity with depth (z)

2) Preferential absorption in the ‘red-end’ of the spectrum

MAR 510 Chemical

Oceanography

Primary production

Low light adapted

High light adapted

High light adapted

Low light adapted

P = Pmax x I/(I+kI)

MAR 510 Chemical

Oceanography

Primary production

Net growth = dp - dr

At the compensation depth (Dc) Net growth = 0, dp = dr For an individual phytoplankton cell The critcal depth(Dcr) is defined such that

When the mixed layer depth (mld) < Dcr , a phyto plankton bloom can occur

Sverdrup (1952)

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

Onset of nutrient limitation

Onset of light limitation

MAR 510 Chemical

Oceanography

Primary production seawifs.gsfc.nasa.gov/SEAWIFS/IMAGES/SEAWIFS_GALLERY.html

Major Coastal Upwelling Zones

A global composite of sea surface chlorophyll concentration

Coastal Upwelling

MAR 510 Chemical

Oceanography

Primary production

Herbland & Le Bouteiller (1981) J. Plank. Res.

MAR 510 Chemical

Oceanography

Primary production

Direction reversed in southern hemisphere

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production seawifs.gsfc.nasa.gov/SEAWIFS/IMAGES/SEAWIFS_GALLERY.html

Martin et al. Fe studies in subarctic N. Pacific

A global composite of sea surface chlorophyll concentration

High-nutrient, low chlorophyll (HNLC)

HNLC

HNLC

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

Martin et al. (1989) Deep-Sea Res.

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production seawifs.gsfc.nasa.gov/SEAWIFS/IMAGES/SEAWIFS_GALLERY.html

Large-Scale Fe Fertilization Experiments

A global composite of sea surface chlorophyll concentration

High-nutrient, low chlorophyll (HNLC)

HNLC

HNLC

MAR 510 Chemical

Oceanography

Primary production

Boyd, P. W., et al. (2000) A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization. Nature 407: 695 - 702.

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

Atmosphere

Aphotic Zone

Euphotic zone

CO2 Biological Pump

CO2

CO2

Organic Matter

Particle sinking, downward transport of DOM

OM decomposition

O2

Phytoplankton (no change in ALK

net decrease in pCO2)

Incident Light

O2

Zooplankton Bacteria N, P, Si, trace metals

N, P, Si, trace metals

Vertical mixing, advection

O2

MAR 510 Chemical

Oceanography

Primary production

Alldredge and Silver (1988) Prog. Oceanogr.

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production

From W. Deuser

MAR 510 Chemical

Oceanography

Primary production

MAR 510 Chemical

Oceanography

Primary production