Biological pump

• Biological carbon pump

  • Moves CO2 from the ocean surface to phytoplankton through photosynthesis. Phytoplankton are microscopic plants and plant-like organisms drifting or floating in the sea/freshwater
  • This effectively converts CO2 into food for zooplankton (microscopic animals) and their predators.
  • Most of the carbon dioxide taken up by phytoplankton is recycled near the surface. About 30% sinks into deeper waters before being converted back into CO2 by marine bacteria.
• High latitudes

  In high latitudes, blooms peak in the summer, when sunlight increases. Mixing from winter storms brings up nutrients from deepter waters.
• Subtropical oceans


  In subtropical oceans, phytoplankton populations drop off in the summer. Warm surface waters don't mix with the cold dense water. Phytoplankton use up the available nutrients and wait until winter.
• Low latitudes


  In low latitudes, seasonal blooms are often linked to monsoon-related changes in winds.
• Differences from year to year

  • ENSO cycles are significant changes from typical sea surface temperatures, wind patterns and rainfall in the Pacific
  • During El Nino events, phytoplankton productivity declines dramatically as trade winds reverse direction.
  • The transition between El Nino and La Nina results in a surge of phytoplankton activity