Ocean acidification

Definition

Ocean acidification refers to the process by which the ocean becomes more acidic due to increased carbon dioxide (CO2) emissions from human activities. As CO2 dissolves in seawater, it forms carbonic acid, which lowers the pH of the water and negatively impacts marine life. This phenomenon is closely linked to climate change, as rising global temperatures and changing ocean conditions exacerbate its effects on aquatic ecosystems and physical systems worldwide.

5 Must Know Facts For Your Next Test

1. Ocean acidification has led to a decrease in the pH of surface ocean waters by about 0.1 units since the beginning of the Industrial Revolution, which corresponds to a 30% increase in acidity.
2. The process primarily affects calcifying organisms, such as corals, mollusks, and some plankton species, impairing their ability to build shells and skeletons.
3. Changes in marine ecosystems due to ocean acidification can disrupt food webs, affecting fish populations and other species that rely on these organisms for food.
4. Ocean acidification is expected to worsen with continued CO2 emissions, potentially reaching a pH level that could threaten many marine species by the end of the century.
5. The impacts of ocean acidification can have far-reaching consequences for human communities that depend on marine resources for food and livelihoods.

Review Questions

• How does ocean acidification affect marine life, particularly calcifying organisms, and what implications does this have for marine ecosystems?
  • Ocean acidification significantly impacts marine life by lowering the availability of carbonate ions, which are essential for calcifying organisms like corals and shellfish to build their shells. As acidity increases, these organisms struggle to maintain their structures, leading to weaker shells and skeletons. This disruption can cause cascading effects throughout marine ecosystems, as species that depend on these organisms for food may decline, altering predator-prey dynamics and overall biodiversity.
• Evaluate the relationship between increased carbon dioxide emissions and ocean acidification, focusing on the long-term trends and potential future scenarios.
  • Increased carbon dioxide emissions from human activities have led to higher concentrations of CO2 in the atmosphere, a significant portion of which is absorbed by the oceans. This absorption causes a chemical reaction that forms carbonic acid, resulting in lower pH levels. Long-term trends indicate that if CO2 emissions continue unabated, ocean acidity could increase dramatically by the end of this century, posing severe risks to marine ecosystems and species dependent on stable pH levels.
• Propose potential strategies that could be implemented to mitigate the effects of ocean acidification on marine ecosystems.
  • Mitigating the effects of ocean acidification requires a multi-faceted approach. Strategies include reducing carbon dioxide emissions through transitioning to renewable energy sources, enhancing energy efficiency, and promoting carbon capture technologies. Additionally, protecting and restoring coastal ecosystems such as mangroves and seagrasses can help absorb CO2 naturally. Educating communities about sustainable fishing practices can also alleviate stress on vulnerable marine populations while fostering resilience against changing conditions.

Related terms

carbon dioxide:

A colorless gas produced by burning fossil fuels and by respiration, which is absorbed by oceans and contributes to ocean acidification.

pH scale: A measure of how acidic or basic a solution is, with lower values indicating higher acidity; ocean acidification results in lower pH levels in seawater.

calcifying organisms: Marine species, such as corals and shellfish, that rely on calcium carbonate to build their shells and skeletons, which are threatened by ocean acidification.