Ocean acidification

Definition

Ocean acidification refers to the process in which the ocean becomes more acidic due to increased carbon dioxide (CO2) levels in the atmosphere. As CO2 is absorbed by seawater, it reacts to form carbonic acid, leading to a decrease in pH levels. This change in acidity can have profound effects on marine ecosystems, impacting coral reefs, shellfish, and other marine organisms that rely on calcium carbonate for their growth and survival.

5 Must Know Facts For Your Next Test

1. Since the Industrial Revolution, the ocean has absorbed about 30% of the excess CO2 produced by human activities, causing a significant decrease in ocean pH.
2. Ocean acidification poses a serious threat to coral reefs, which are vital ecosystems that support diverse marine life and provide benefits such as coastal protection and tourism.
3. Shell-forming organisms like mollusks and some plankton species are particularly vulnerable to ocean acidification as it weakens their calcium carbonate shells, affecting their survival rates.
4. The changes in ocean chemistry can disrupt food webs and fisheries, impacting human communities that rely on these resources for their livelihoods.
5. Scientists predict that if CO2 emissions continue at the current rate, the oceans could become 150% more acidic by the end of this century compared to pre-industrial levels.

Review Questions

• How does increased carbon dioxide in the atmosphere contribute to ocean acidification, and what are its immediate effects on marine life?
  • Increased carbon dioxide from human activities is absorbed by the ocean, where it reacts with seawater to form carbonic acid. This process lowers the pH of the water, making it more acidic. The immediate effects on marine life include harmful impacts on organisms that rely on calcium carbonate for their shells or skeletons, such as corals and shellfish, making it harder for them to grow and survive.
• Discuss the long-term implications of ocean acidification on marine ecosystems and human economies dependent on those ecosystems.
  • The long-term implications of ocean acidification include the potential collapse of coral reefs and declines in populations of shellfish and other calcifying organisms. This decline not only threatens biodiversity but also impacts human economies reliant on fishing and tourism associated with healthy marine ecosystems. As these resources dwindle, communities dependent on them may face economic hardships and loss of livelihoods.
• Evaluate potential strategies that could be implemented to mitigate ocean acidification and protect vulnerable marine ecosystems.
  • To mitigate ocean acidification, strategies may include reducing carbon emissions through cleaner energy sources and promoting sustainable fishing practices to protect marine biodiversity. Restoring coastal habitats like mangroves and seagrasses can also help absorb CO2 and improve resilience against acidification. International cooperation is essential for effective policies that address climate change and its impact on oceans, ensuring that vulnerable marine ecosystems receive adequate protection from ongoing threats.

Related terms

Carbon dioxide: A colorless gas produced by burning fossil fuels, natural processes, and respiration, which is a major contributor to climate change and ocean acidification.

pH scale: A scale used to measure how acidic or basic a solution is, where lower values indicate higher acidity and higher values indicate higher alkalinity.

Coral bleaching: The loss of color in corals due to stress from environmental changes, including rising temperatures and ocean acidification, which can lead to coral death.