Biological pump

Definition

The biological pump is a crucial process in the ocean that describes how biological activity, particularly by phytoplankton, facilitates the transfer of carbon dioxide (CO2) from the atmosphere to the deep ocean. This process plays a key role in regulating global climate by sequestering carbon and cycling nutrients, thus impacting marine ecosystems and biogeochemical cycles in the open ocean.

5 Must Know Facts For Your Next Test

1. Phytoplankton absorb CO2 during photosynthesis, converting it into organic matter which sinks to deeper layers of the ocean when these organisms die or are consumed.
2. The biological pump significantly influences global carbon cycles, accounting for an estimated 50% of the total carbon uptake by oceans.
3. This process is also impacted by ocean temperature, nutrient availability, and changes in ocean currents, which can alter the efficiency of carbon sequestration.
4. Regions known as high-nutrient low-chlorophyll (HNLC) areas demonstrate how limited nutrients can restrict biological pump activity despite favorable conditions for phytoplankton growth.
5. Climate change poses risks to the biological pump's efficiency, as alterations in temperature and ocean stratification can disrupt nutrient cycling and phytoplankton productivity.

Review Questions

• How does phytoplankton contribute to the biological pump and what implications does this have for marine ecosystems?
  • Phytoplankton are essential to the biological pump as they capture atmospheric CO2 through photosynthesis, forming organic matter that eventually sinks to deeper ocean layers. This process not only sequesters carbon but also supports marine food webs, as many marine organisms rely on phytoplankton as their primary food source. The health of marine ecosystems is closely tied to phytoplankton dynamics since disruptions in their populations can lead to cascading effects throughout the food chain.
• Evaluate the impact of changing ocean conditions on the effectiveness of the biological pump in carbon sequestration.
  • Changing ocean conditions, such as increased temperatures and altered nutrient availability due to climate change, can significantly impact the biological pump's effectiveness. Warmer waters can lead to stratification, limiting nutrient mixing and reducing phytoplankton growth. Additionally, shifts in ocean currents may influence nutrient distribution, further affecting productivity. These changes could lead to decreased carbon sequestration capabilities, exacerbating atmospheric CO2 levels and impacting global climate regulation.
• Synthesize information on how human activities may affect the biological pump and discuss potential long-term implications for climate change.
  • Human activities, particularly fossil fuel combustion and land-use changes, increase atmospheric CO2 levels and alter nutrient inputs into oceans through runoff and pollution. These changes can enhance or disrupt the biological pump's function; for instance, excess nutrients from agricultural runoff may lead to harmful algal blooms that outcompete phytoplankton essential for carbon capture. Over time, if these trends continue, we could face significant disruptions to global carbon cycling and accelerated climate change effects due to reduced efficacy in sequestering CO2 in oceans.

Related terms

phytoplankton: Microscopic marine algae that form the base of the oceanic food web, responsible for photosynthesis and producing a significant portion of the world's oxygen.

carbon sequestration: The process of capturing and storing atmospheric carbon dioxide, which helps to mitigate climate change by reducing greenhouse gas concentrations.

nutrient cycling: The movement and exchange of organic and inorganic matter back into the production of living matter, essential for maintaining ecosystem productivity.