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 phenomenon occurs when CO2 is absorbed by seawater, leading to a chemical reaction that forms carbonic acid, which lowers the pH of the ocean. As a result, this shift in ocean chemistry impacts marine ecosystems, particularly organisms that rely on calcium carbonate for their shells and skeletons, making it an important concern for climate change and human activities affecting biogeochemical cycles.

5 Must Know Facts For Your Next Test

1. The ocean absorbs approximately 30% of the CO2 emitted into the atmosphere, significantly increasing its acidity over time.
2. As the ocean's pH drops, it affects the availability of carbonate ions needed by calcifying organisms to produce their shells and skeletons.
3. Ocean acidification can disrupt food webs by impacting marine life such as plankton, which are foundational to the marine ecosystem.
4. The current rate of ocean acidification is faster than any natural changes observed in the past 65 million years.
5. Increased acidity can also affect the behavior and physiology of marine species, including fish, potentially impacting fisheries and human food sources.

Review Questions

• How does ocean acidification relate to climate change and what are its implications for marine life?
  • Ocean acidification is directly related to climate change through the increased levels of carbon dioxide produced by human activities. As CO2 levels rise in the atmosphere, a significant portion is absorbed by oceans, leading to increased acidity. This change in ocean chemistry has serious implications for marine life, especially for calcifying organisms like corals and shellfish that struggle to maintain their structures in more acidic waters.
• Evaluate how human activities contribute to ocean acidification and its effects on biogeochemical cycles.
  • Human activities, particularly the burning of fossil fuels and deforestation, release large amounts of carbon dioxide into the atmosphere. When this CO2 dissolves in seawater, it leads to ocean acidification. This process alters biogeochemical cycles by affecting nutrient availability and cycling rates in marine ecosystems. For instance, changes in carbonate chemistry can impact the growth rates of phytoplankton, which are crucial for carbon cycling and as a primary food source for many marine organisms.
• Synthesize information on potential solutions to mitigate ocean acidification and assess their feasibility.
  • To mitigate ocean acidification, several strategies can be considered, including reducing greenhouse gas emissions through renewable energy sources and improving carbon capture technologies. Additionally, protecting marine ecosystems like mangroves and seagrasses that naturally absorb CO2 can help buffer against changes in pH. While these solutions are feasible and necessary for long-term sustainability, they require global cooperation, significant investment, and public awareness to effectively combat this pressing issue.

Related terms

carbon dioxide:

A greenhouse gas that is produced by burning fossil fuels and other human activities, contributing to global warming and ocean acidification.

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

calcifying organisms: Marine species, such as corals and shellfish, that build their shells and skeletons from calcium carbonate, which is affected by changes in ocean acidity.