Ocean acidification

Definition

Ocean acidification refers to the process by which the ocean becomes more acidic due to the absorption of excess atmospheric CO2, resulting in a decrease in pH levels. This phenomenon is closely linked to climate change, as increased carbon emissions lead to higher levels of CO2 in the atmosphere, which in turn gets absorbed by the oceans, impacting marine ecosystems and species.

5 Must Know Facts For Your Next Test

1. Since the beginning of the Industrial Revolution, ocean surface pH has dropped by about 0.1 units, which corresponds to approximately a 30% increase in acidity.
2. Ocean acidification can have detrimental effects on marine life, particularly organisms that rely on calcium carbonate for their shells and skeletons, like corals and certain shellfish.
3. The changing chemistry of ocean waters can disrupt food webs, affecting species interactions and overall biodiversity within marine ecosystems.
4. Ocean acidification is often referred to as the 'evil twin' of climate change due to its interconnected nature with rising temperatures and CO2 levels.
5. Predictive models suggest that if current trends continue, ocean acidity could increase by another 0.3 to 0.4 units by the end of this century, posing severe risks to marine ecosystems.

Review Questions

• How does ocean acidification affect marine organisms that rely on calcification for their survival?
  • Ocean acidification significantly impacts marine organisms that depend on calcification because lower pH levels reduce the availability of carbonate ions necessary for forming calcium carbonate shells and skeletons. This can lead to weaker structures and higher mortality rates in species such as corals and shellfish. As these key species struggle to survive, it can disrupt entire marine ecosystems due to their roles in food webs and habitat formation.
• Discuss the relationship between ocean acidification and major climate events throughout Earth's history.
  • Ocean acidification has occurred during several major climate events in Earth's history, often linked to high levels of atmospheric CO2. For instance, during the Paleocene-Eocene Thermal Maximum, rapid increases in temperature correlated with significant drops in ocean pH. Understanding this historical context can help scientists predict potential future impacts of current anthropogenic carbon emissions on marine life and ecosystem stability.
• Evaluate the long-term ecological consequences of ocean acidification on marine biodiversity following mass extinction events.
  • The long-term ecological consequences of ocean acidification on marine biodiversity could mirror those observed after past mass extinction events, where shifts in ocean chemistry led to significant declines in species diversity. Such changes can result in reduced resilience of ecosystems, loss of habitat-forming species like corals, and altered species compositions. Evaluating these impacts is crucial for understanding how modern acidification may lead to similar patterns of biodiversity loss and ecosystem disruption, highlighting the need for effective conservation strategies.

Related terms

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

calcification: The process by which marine organisms, such as corals and shellfish, build their shells and skeletons using calcium carbonate, which can be affected by changes in ocean chemistry.

biogeochemical cycles:

Natural processes that recycle nutrients in various chemical forms from the environment to living organisms and back again, influencing ecosystem health.