Marine ecosystems

Definition

Marine ecosystems are diverse aquatic environments that exist in oceans, seas, and coastal areas, characterized by their unique biological communities and physical conditions. These ecosystems play a crucial role in the carbon cycle, as they are involved in the absorption and storage of carbon dioxide through processes like photosynthesis by marine plants and phytoplankton, which in turn supports complex food webs and influences global climate patterns.

5 Must Know Facts For Your Next Test

1. Marine ecosystems cover about 71% of the Earth's surface and are home to a vast array of species, from microscopic plankton to large whales.
2. These ecosystems act as major carbon sinks, with oceans absorbing around 30% of the carbon dioxide emitted by human activities.
3. Healthy marine ecosystems contribute to global oxygen production, with phytoplankton generating more than half of the oxygen in the atmosphere.
4. The degradation of marine ecosystems, such as through pollution and overfishing, can significantly impact their ability to sequester carbon and mitigate climate change.
5. Marine ecosystems are interconnected with terrestrial ecosystems; changes in one can have cascading effects on the other through the carbon cycle.

Review Questions

• How do marine ecosystems contribute to the overall carbon cycle?
  • Marine ecosystems contribute to the carbon cycle primarily through the process of photosynthesis performed by phytoplankton and other marine plants. These organisms absorb carbon dioxide from the water during photosynthesis, converting it into organic matter that supports various marine food webs. Additionally, when marine organisms die, their remains can sink to the ocean floor, effectively sequestering carbon for long periods and influencing overall atmospheric carbon levels.
• Discuss the implications of human activity on marine ecosystems and their role in the carbon cycle.
  • Human activities such as pollution, overfishing, and coastal development can severely impact marine ecosystems and their ability to function within the carbon cycle. For example, pollution can lead to dead zones where oxygen levels are too low for most marine life, disrupting food chains. Overfishing reduces biodiversity and can destabilize entire ecosystems. These changes hinder the capacity of oceans to absorb CO2, exacerbating climate change and its associated effects.
• Evaluate the significance of coral reefs within marine ecosystems concerning carbon storage and biodiversity.
  • Coral reefs are incredibly significant within marine ecosystems as they support high levels of biodiversity and serve as crucial habitats for numerous marine species. They also play a role in carbon storage by forming calcium carbonate structures that sequester carbon over long periods. The health of coral reefs is vital; when they degrade due to climate change or human impacts, not only is biodiversity at risk, but their ability to sequester carbon is diminished. This highlights the interconnectedness of biodiversity conservation and climate change mitigation strategies.

Related terms

Phytoplankton: Microscopic marine plants that perform photosynthesis and are foundational to marine food webs, contributing significantly to carbon fixation in ocean ecosystems.

Coral Reefs: Highly productive marine ecosystems built by coral polyps, providing habitat for a diverse array of marine life while also playing a role in carbon cycling through calcium carbonate formation.

Ocean Acidification: The process by which increased levels of carbon dioxide in the atmosphere lead to higher concentrations of carbonic acid in oceans, affecting marine life and ecosystems.