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. This change in pH affects marine life and ecosystems, altering chemical equilibria and disrupting biological processes vital for the health of oceanic environments.

5 Must Know Facts For Your Next Test

1. Since the beginning of the industrial era, the ocean's average pH has dropped by about 0.1 units, indicating a significant increase in acidity.
2. Ocean acidification primarily affects calcifying organisms, making it harder for them to build shells and skeletons, leading to potential declines in their populations.
3. The process occurs when CO2 dissolves in seawater, forming carbonic acid which dissociates into bicarbonate and hydrogen ions, thus lowering pH.
4. Up to 30% of atmospheric CO2 emissions are absorbed by the oceans, showing a direct link between greenhouse gas emissions and ocean chemistry changes.
5. Coral reefs are particularly vulnerable to acidification, as they rely on calcium carbonate for their structure; declining reef health impacts marine biodiversity and fisheries.

Review Questions

• How does ocean acidification directly impact marine ecosystems and biodiversity?
  • Ocean acidification has a profound effect on marine ecosystems as it disrupts the ability of calcifying organisms, like corals and shellfish, to produce their calcium carbonate structures. This disruption can lead to declines in these species, which play critical roles in their ecosystems. Additionally, weakened coral reefs lose their ability to provide habitat and protection for various marine species, ultimately reducing biodiversity within those environments.
• Discuss the relationship between anthropogenic CO2 emissions and ocean acidification. What are the broader implications for climate change?
  • Anthropogenic CO2 emissions from fossil fuel combustion significantly contribute to ocean acidification by increasing the concentration of CO2 in seawater. As oceans absorb more CO2, they become more acidic, affecting marine life and altering food webs. The broader implications include diminished fish stocks that many communities rely on for food and livelihood, as well as compromised marine ecosystems that play a crucial role in carbon sequestration and regulating global climate.
• Evaluate potential strategies for mitigating ocean acidification and protecting vulnerable marine species. How might these strategies contribute to climate change adaptation?
  • Mitigating ocean acidification involves reducing CO2 emissions through renewable energy adoption, enhancing carbon capture technologies, and improving energy efficiency. Protecting vulnerable marine species may require establishing marine protected areas that enhance resilience against acidification impacts. These strategies not only aim to safeguard marine ecosystems but also contribute to climate change adaptation by preserving biodiversity, supporting fisheries management, and maintaining the ocean's capacity to sequester carbon, which is essential for addressing climate challenges.

Related terms

Carbon Dioxide: A colorless, odorless gas produced by burning fossil fuels and through other natural processes; it is a key contributor to both global warming and ocean acidification.

pH Scale:

A scale used to specify the acidity or basicity of an aqueous solution, where lower values indicate higher acidity and higher values indicate alkalinity.

Calcifying Organisms: Marine organisms, such as corals and certain shellfish, that build their shells or skeletons from calcium carbonate, which is impacted by changes in ocean chemistry.