How is organic carbon (biosyn by phytoplankton) transformed in upper ocean? Why is the fact that particulate organic C sinks to the deep ocean important in terms of nutrient cycling? How does it affect the composition of deep ocean waters.
It is decayed by microbial bacteria releasing CO2 and other nutrients, making them available to be used again by phtyoplankton UNTIL ultimately deposition locks away the carbon/nitrogen/sulfur/phoshorus in ocean sediments
Important bc nutrients can still reach bottomdwellers (stingrays, lobster, crabs, etc). Also, increases chance for nutrients to be buried/mineralized into sediment as sink taking it out from the cycle.
Makes deep ocean waters slightly more nutritious/