Ocean Acidification

Definition

Ocean acidification refers to the process by which carbon dioxide (CO2) from the atmosphere is absorbed by seawater, leading to a decrease in pH levels and making the ocean more acidic. This change in ocean chemistry has significant implications for marine ecosystems, affecting species interactions and food webs, as well as posing challenges for fisheries management and amplifying the impacts of climate change on ocean health.

5 Must Know Facts For Your Next Test

1. The ocean has absorbed about 30% of the CO2 released into the atmosphere since the Industrial Revolution, leading to a significant drop in pH levels.
2. Ocean acidification affects calcifying organisms like corals, mollusks, and some plankton species by reducing their ability to produce calcium carbonate shells and skeletons.
3. Changes in marine ecosystems due to ocean acidification can disrupt food webs by impacting species that serve as key food sources for fish and other animals.
4. Fisheries management must adapt to the challenges posed by ocean acidification, including shifts in species distributions and the health of commercially important fish populations.
5. Ocean acidification is expected to exacerbate the impacts of climate change, as stressed marine ecosystems become more vulnerable to other environmental changes.

Review Questions

• How does ocean acidification affect marine ecosystems and what implications does this have for biodiversity?
  • Ocean acidification has a profound effect on marine ecosystems by altering species interactions and affecting organisms that rely on calcium carbonate for their structures. As pH levels decline, species like corals and shellfish struggle to maintain their shells and skeletons, leading to declines in their populations. This can disrupt food webs and reduce biodiversity as key species are affected, resulting in cascading impacts throughout the ecosystem.
• In what ways does ocean acidification challenge ecosystem-based fisheries management strategies?
  • Ocean acidification presents significant challenges for ecosystem-based fisheries management by altering species distributions and affecting the health of commercially important fish populations. As some species become less viable due to changing ocean chemistry, fisheries may need to adapt their strategies to account for shifts in catch potential and ensure sustainable practices. Additionally, managers must consider the impact of acidification on critical habitats, such as coral reefs and shellfish beds, which support fisheries productivity.
• Evaluate the broader consequences of ocean acidification on climate change impacts and marine life sustainability.
  • Ocean acidification compounds the effects of climate change on marine environments, leading to increased stress on marine life and disrupting natural processes. The rising CO2 levels not only make oceans more acidic but also contribute to warming waters, further endangering species that are already vulnerable. This interplay threatens marine life sustainability by diminishing habitats essential for reproduction and growth, potentially leading to declines in fish stocks that are vital for food security and economic stability worldwide.

Related terms

Carbon Dioxide: A greenhouse gas produced by human activities, such as burning fossil fuels, which is a primary driver of ocean acidification when absorbed by seawater.

pH Level: A measure of how acidic or basic a solution is, with lower values indicating higher acidity; ocean acidification results in a decline in pH levels.

Calcifying Organisms: Marine organisms, such as corals and shellfish, that build their structures using calcium carbonate, which becomes more difficult to form in increasingly acidic waters.