Acidification

Definition

Acidification refers to the process by which the pH level of a solution decreases, becoming more acidic. In the context of ocean waters, this process is primarily driven by the absorption of excess atmospheric carbon dioxide (CO2), leading to chemical reactions that form carbonic acid. This increase in acidity can significantly impact marine ecosystems, affecting species composition, biodiversity, and overall ocean health.

5 Must Know Facts For Your Next Test

1. Since the beginning of the Industrial Revolution, ocean surface waters have experienced an approximate decrease in pH of 0.1 units, indicating a significant increase in acidity.
2. The process of acidification can hinder the ability of marine organisms to produce calcium carbonate, which is essential for their shells and skeletal structures.
3. Coral reefs are particularly vulnerable to acidification, as it can lead to weakened structures and reduced growth rates, threatening the entire ecosystem that relies on them.
4. Ocean acidification can disrupt food webs by impacting the availability of plankton, which forms the foundation of marine food chains.
5. As acidification progresses, it can lead to changes in species distribution and biodiversity, favoring more acid-tolerant species over those that are sensitive to changes in pH.

Review Questions

• How does ocean acidification occur and what are its primary drivers?
  • Ocean acidification occurs when excess atmospheric CO2 is absorbed by ocean waters, leading to a series of chemical reactions that produce carbonic acid. This process lowers the pH of seawater, making it more acidic. The primary driver of this phenomenon is human-induced CO2 emissions from fossil fuel combustion and deforestation, which have increased dramatically since the Industrial Revolution.
• Evaluate the potential ecological consequences of ocean acidification on marine life, particularly regarding coral reefs.
  • Ocean acidification poses severe ecological consequences for marine life, especially coral reefs. The increased acidity affects coral calcification rates, making it more difficult for corals to build and maintain their calcium carbonate structures. This decline not only threatens coral health but also endangers the diverse marine species that depend on coral reefs for habitat and food sources. As a result, entire ecosystems can be jeopardized due to decreased coral resilience against environmental stressors.
• Assess the broader implications of ocean acidification for global carbon cycling and climate change mitigation efforts.
  • The broader implications of ocean acidification for global carbon cycling are significant. As oceans continue to absorb increasing levels of CO2, their capacity as a carbon sink may be compromised due to changes in chemistry and biology. This could accelerate climate change impacts if less CO2 is sequestered in oceans. Moreover, addressing ocean acidification requires coordinated global efforts to reduce greenhouse gas emissions and enhance climate change mitigation strategies to protect marine ecosystems while maintaining their role in carbon regulation.

Related terms

Oceanic Carbon Sink: Oceanic carbon sinks are natural processes in which oceans absorb CO2 from the atmosphere, helping to regulate global carbon levels.

pH Scale: The pH scale is a measure of acidity or alkalinity, ranging from 0 (very acidic) to 14 (very basic), with 7 being neutral.

Calcium Carbonate: Calcium carbonate is a chemical compound that marine organisms like corals and shellfish use to build their shells and skeletons; its formation is affected by ocean acidification.