Biological pump

Definition

The biological pump is a critical process in ocean ecosystems where organic carbon is transferred from the surface waters to the deep ocean through biological activity, primarily by phytoplankton. This process plays a key role in regulating global carbon cycles and impacts the ocean's ability to sequester carbon dioxide, ultimately influencing climate change.

5 Must Know Facts For Your Next Test

1. Phytoplankton absorb carbon dioxide during photosynthesis, producing organic matter that forms the foundation of the biological pump.
2. When phytoplankton die or are consumed by zooplankton, organic matter sinks to deeper layers of the ocean, transporting carbon away from the atmosphere.
3. The efficiency of the biological pump is influenced by factors such as nutrient availability, water temperature, and light conditions.
4. Diel vertical migration plays a significant role in enhancing the biological pump, as zooplankton ascend to feed on phytoplankton at night and descend during the day, facilitating carbon transport.
5. The biological pump is essential for maintaining the balance of carbon in the atmosphere and oceans, thus playing a key role in mitigating climate change.

Review Questions

• How does phytoplankton contribute to the biological pump and what role do they play in the carbon cycle?
  • Phytoplankton are crucial to the biological pump as they perform photosynthesis, absorbing carbon dioxide from the atmosphere and converting it into organic matter. This organic matter forms the foundation of marine food webs. When phytoplankton die or are consumed by other organisms, their biomass sinks to deeper ocean layers, effectively transporting carbon away from the surface and into the depths, thus aiding in regulating atmospheric carbon levels.
• Discuss how diel vertical migration affects the efficiency of the biological pump.
  • Diel vertical migration significantly enhances the efficiency of the biological pump by influencing how and when zooplankton interact with phytoplankton. Zooplankton rise to feed on phytoplankton during nighttime when it is safer from predation. As they descend during daylight hours, they transport organic matter to deeper waters. This behavior not only aids in carbon transport but also helps maintain nutrient cycling in the ocean.
• Evaluate the implications of changes in phytoplankton populations on global carbon cycles and climate change.
  • Changes in phytoplankton populations can have profound implications for global carbon cycles and climate change. A decline in phytoplankton due to factors like rising ocean temperatures or nutrient depletion can reduce the efficiency of the biological pump, leading to less carbon being sequestered in deep waters. This results in higher levels of atmospheric carbon dioxide, which exacerbates climate change. Conversely, a bloom of phytoplankton may temporarily enhance carbon uptake but could also lead to hypoxia if decomposition consumes oxygen in deeper waters. Thus, understanding these dynamics is essential for predicting climate change impacts.

Related terms

phytoplankton: Microscopic marine organisms that perform photosynthesis, forming the base of the oceanic food web and contributing significantly to the biological pump.

carbon sequestration: The process of capturing and storing atmospheric carbon dioxide in various forms, including through biological processes like the biological pump.

diel vertical migration: A behavioral pattern in which zooplankton and other organisms migrate vertically in the water column in response to light, which can enhance the efficiency of the biological pump.