Ocean acidification

Definition

Ocean acidification refers to the process by which the ocean becomes more acidic due to increased absorption of carbon dioxide (CO2) from the atmosphere. This phenomenon has significant implications for marine ecosystems, carbonate chemistry, and global biogeochemical cycles.

5 Must Know Facts For Your Next Test

1. Ocean acidification is primarily caused by the absorption of approximately 30% of atmospheric CO2 by the oceans, leading to a reduction in pH levels.
2. This process poses a serious threat to calcifying organisms like corals and mollusks, which struggle to maintain their calcium carbonate structures in more acidic waters.
3. Ocean acidification can disrupt food webs and marine biodiversity, affecting species interactions and ecosystem functions.
4. The changes in ocean chemistry can impact global biogeochemical cycles by altering nutrient availability and influencing primary production.
5. Mitigating ocean acidification requires reducing CO2 emissions and enhancing carbon capture strategies to protect marine ecosystems and their services.

Review Questions

• How does ocean acidification impact marine organisms that rely on calcium carbonate for their structures?
  • Ocean acidification negatively affects marine organisms that depend on calcium carbonate, such as corals and shellfish. As the ocean becomes more acidic, the availability of carbonate ions decreases, making it harder for these organisms to form and maintain their shells and skeletons. This impacts their survival, growth, and reproductive success, ultimately disrupting marine ecosystems and biodiversity.
• Discuss the role of carbon dioxide emissions in driving ocean acidification and its implications for global biogeochemical cycles.
  • Carbon dioxide emissions from human activities are a primary driver of ocean acidification. As CO2 levels in the atmosphere increase, more CO2 is absorbed by the oceans, leading to a decline in pH levels. This shift alters the chemical balance of seawater, affecting key processes within global biogeochemical cycles, including nutrient availability for primary producers and the cycling of essential elements like nitrogen and phosphorus.
• Evaluate the potential long-term effects of ocean acidification on marine ecosystems and human communities dependent on them.
  • The long-term effects of ocean acidification could have profound consequences for marine ecosystems and human communities reliant on them. Ecosystem shifts may lead to declines in fish populations that are critical for food security and local economies. Additionally, altered marine biodiversity can disrupt ecosystem services such as coastal protection provided by coral reefs. Addressing these challenges requires comprehensive strategies to reduce greenhouse gas emissions and promote sustainable fisheries management.

Related terms

Carbon Cycle: The natural process through which carbon is exchanged between the atmosphere, land, oceans, and living organisms, playing a critical role in regulating climate and supporting life.

pH Scale: A measure of the acidity or basicity of a solution, with lower values indicating higher acidity; the ocean's pH has been decreasing due to increased CO2 absorption.

Calcifying Organisms: Marine organisms such as corals and shellfish that rely on calcium carbonate to build their shells and skeletons, which are affected by changes in ocean chemistry.