Ocean acidification

Definition

Ocean acidification refers to the process by which the ocean becomes more acidic due to increased levels of carbon dioxide (CO2) in the atmosphere. This occurs when CO2 is absorbed by seawater, leading to chemical reactions that decrease the pH of the ocean, making it more acidic. As a result, marine ecosystems and organisms that rely on calcium carbonate, such as coral reefs and shellfish, face significant challenges to their survival and growth.

5 Must Know Facts For Your Next Test

1. Ocean acidification is caused primarily by the absorption of excess atmospheric CO2, which has risen significantly due to human activities such as burning fossil fuels.
2. The decrease in ocean pH affects marine life, particularly organisms that build shells and skeletons from calcium carbonate, making it harder for them to grow and survive.
3. Coral reefs are particularly vulnerable to ocean acidification; as the water becomes more acidic, it can lead to coral bleaching and decreased reef resilience.
4. Current estimates suggest that the ocean has become about 30% more acidic since the beginning of the Industrial Revolution.
5. The long-term impacts of ocean acidification could disrupt entire marine food webs, impacting fisheries and communities that rely on marine resources for their livelihoods.

Review Questions

• What are the primary causes of ocean acidification and how do they impact marine ecosystems?
  • The primary cause of ocean acidification is the increased levels of carbon dioxide (CO2) in the atmosphere, primarily from human activities like burning fossil fuels. When CO2 is absorbed by seawater, it leads to a series of chemical reactions that decrease the pH of the ocean. This change in acidity negatively affects marine ecosystems by harming organisms that rely on calcium carbonate for their shells and skeletons, leading to challenges for species such as corals and shellfish.
• Discuss the implications of ocean acidification on coral reefs and their associated ecosystems.
  • Ocean acidification has severe implications for coral reefs, which are highly sensitive to changes in pH. Increased acidity hampers the ability of corals to produce calcium carbonate, essential for building their skeletons. As corals struggle to grow and maintain their structure, it leads to weakened reefs that can result in habitat loss for countless marine species that depend on them for shelter and food. Consequently, this can disrupt the entire marine ecosystem that relies on healthy coral reef systems.
• Evaluate the potential socio-economic consequences of ocean acidification on coastal communities dependent on marine resources.
  • Ocean acidification poses significant socio-economic challenges for coastal communities that rely on marine resources for their livelihoods. As shellfish populations decline due to increased acidity affecting their ability to form shells, fisheries may face reduced yields. This not only threatens local economies but also food security for communities dependent on seafood. Moreover, with coral reefs deteriorating due to acidification, tourism industries linked to reef health may also suffer, leading to broader economic impacts in these regions.

Related terms

Carbon dioxide (CO2): A colorless, odorless gas that is naturally present in the atmosphere as a result of volcanic eruptions, respiration, and human activities like burning fossil fuels.

pH scale: A scale used to measure how acidic or basic a solution is, ranging from 0 (very acidic) to 14 (very basic), with 7 being neutral.

Calcium carbonate: A chemical compound (CaCO3) found in rocks, shells, and coral, which is crucial for the formation of skeletons and shells in many marine organisms.