1.3.5 What are the carbon cycle processes in the ocean?
What are the carbon cycle processes in the ocean?
Shell building organisms
Absorb carbonate ions to form shells
Make needles and shields
Silicate and calcium carbonate
Over millions of years, shells fossilise
Found in stones for building
Fossils = geological history
Die but don't decompose
Falls to sea floor = lithicates in rock
only food source for some animals
base of marine food web
need sunlight, nutrients & water to grow
nutrients fertilise phytoplankton = growth - up-welling bring nutrients up
take in CO2 and release O2
Ocean absorbs more carbon dioxide
water = more acidic
Mixing of surface and deep ocean waters by
currents, allowing carbon to be distributed more evenly. CO2 enters the oceans from the atmosphere by
, surface currents transfer the water
towards the poles
cools, becomes more dense and sinks
occurs in only a few places.
carries dissolved carbon to the
where it may remain for
. Eventually, deep ocean currents transfer the carbon to areas of
. There this cold, carbon-rich water rises to the surface and CO2 diffuses back into the atmosphere.
Carbon is exchanged between the
through marine organisms.
of all carbon fixation by photosynthesis takes place in the ocean. Around
of carbon is drawn from the atmosphere by the pump each year.
Ocean regulates climate
1/3 of human generated carbon
Ocean will become less efficient at keeping carbon out of the atmosphere
Warm water = holds less carbon = more in the atmosphere
Control how much carbon in the atmosphere (regulate climate)
Ocean floor sediments - largest carbon store