Ocean acidification

Definition

Ocean acidification refers to the process by which the ocean becomes more acidic due to the increased absorption of carbon dioxide (CO2) from the atmosphere. This phenomenon is primarily driven by human activities, especially the burning of fossil fuels, which leads to higher levels of CO2 in the atmosphere and consequently in ocean waters, disrupting marine ecosystems and impacting organisms that rely on calcium carbonate for their shells and skeletons.

5 Must Know Facts For Your Next Test

1. Since the beginning of the Industrial Revolution, the ocean has absorbed about 30% of the CO2 emitted into the atmosphere, leading to a decrease in pH levels.
2. The decrease in pH can have harmful effects on marine life, particularly organisms such as corals, mollusks, and certain plankton species that depend on calcium carbonate to form their shells.
3. Ocean acidification can disrupt the food web by affecting species at different trophic levels, potentially leading to declines in fish populations that rely on these organisms for food.
4. The impacts of ocean acidification are expected to intensify with ongoing climate change, making it crucial for marine conservation efforts and policy decisions.
5. Monitoring ocean acidity is vital for understanding long-term changes in marine environments and developing strategies to mitigate its effects on marine biodiversity.

Review Questions

• What are the primary causes of ocean acidification and how do they relate to human activities?
  • The primary cause of ocean acidification is the increased absorption of carbon dioxide from the atmosphere into the oceans. This process is largely driven by human activities, particularly the burning of fossil fuels for energy. As CO2 levels rise in the atmosphere due to industrialization and deforestation, a significant portion is absorbed by the oceans, leading to chemical reactions that lower seawater pH and increase acidity.
• How does ocean acidification affect marine organisms that rely on calcium carbonate?
  • Ocean acidification poses a significant threat to marine organisms that rely on calcium carbonate to build their shells and skeletons, such as corals and mollusks. The increased acidity in ocean waters reduces the availability of carbonate ions, which are essential for these organisms to form calcium carbonate structures. As a result, these species may experience weakened shells or even difficulty in growth and reproduction, which can have cascading effects throughout marine ecosystems.
• Evaluate the potential long-term impacts of ocean acidification on marine biodiversity and human economies reliant on ocean resources.
  • The long-term impacts of ocean acidification on marine biodiversity could be profound, leading to declines in key species that play critical roles in ecosystem function. As vulnerable species like corals and shellfish struggle to survive, entire marine ecosystems could shift or collapse, affecting biodiversity at multiple levels. Human economies that depend on fishing, tourism, and coastal protection could also suffer significant losses as fish populations decline and coral reefs degrade. This highlights the urgent need for global action to address carbon emissions and protect marine environments.

Related terms

Carbon dioxide: A colorless gas produced by burning fossil fuels and other organic materials; it is a significant greenhouse gas that contributes to climate change.

Calcium carbonate: A chemical compound found in rocks, shells, and coral; it is essential for marine organisms such as mollusks and corals to build their shells and skeletons.

Marine ecosystem: A complex network of living organisms, including plants, animals, and microorganisms, that interact with each other and their environment in oceanic habitats.