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. When CO2 is absorbed by seawater, it reacts with water to form carbonic acid, lowering the pH of the ocean. This change in acidity can significantly affect marine life, especially organisms that rely on calcium carbonate for their shells and skeletons, highlighting important interactions between multiple environmental stressors and climate change.

5 Must Know Facts For Your Next Test

1. Since the beginning of the industrial revolution, the ocean's average pH has dropped by about 0.1 units, which corresponds to a 30% increase in acidity.
2. Ocean acidification can impair the ability of calcifying organisms to build their shells and skeletons, leading to reduced survival rates and overall biodiversity loss in marine ecosystems.
3. Coral reefs are particularly susceptible to ocean acidification, which can weaken their structure and hinder their ability to recover from bleaching events caused by other stressors.
4. The effects of ocean acidification can also have cascading impacts on marine food webs, as species that rely on calcifying organisms for food may face declines in availability.
5. Mitigation strategies for ocean acidification include reducing carbon emissions and enhancing marine protected areas to bolster the resilience of vulnerable marine species.

Review Questions

• How does ocean acidification impact marine calcifying organisms and what could be the broader implications for marine ecosystems?
  • Ocean acidification affects marine calcifying organisms by decreasing their ability to produce calcium carbonate, essential for forming shells and skeletons. As these organisms struggle to survive, it can lead to decreased populations of species like corals and mollusks. The broader implications include disruptions in marine food webs, where predators that rely on these organisms may face food shortages, ultimately threatening overall biodiversity in marine ecosystems.
• Discuss the relationship between increased atmospheric CO2 levels and ocean acidification, focusing on feedback mechanisms that may arise.
  • Increased atmospheric CO2 levels directly contribute to ocean acidification as excess CO2 is absorbed by seawater. This process creates carbonic acid, which lowers ocean pH. Feedback mechanisms may arise as declining populations of calcifying organisms reduce the ocean's ability to sequester carbon through biological processes. The resultant decrease in biodiversity can further impair ecosystem functions that mitigate carbon emissions, perpetuating a cycle that exacerbates both climate change and ocean health.
• Evaluate potential strategies for addressing ocean acidification and how they might interact with broader climate change mitigation efforts.
  • Addressing ocean acidification requires multifaceted strategies like reducing global carbon emissions through renewable energy adoption and enhancing carbon sequestration methods in both terrestrial and marine environments. Protecting marine ecosystems, such as establishing marine protected areas, can help bolster resilience against acidification impacts. These strategies interact with broader climate change mitigation efforts by not only targeting atmospheric CO2 reduction but also fostering healthier marine environments that contribute to carbon storage, thereby creating a synergistic approach to tackling both ocean health and climate change.

Related terms

pH scale: A logarithmic scale used to specify the acidity or basicity of an aqueous solution, ranging from 0 (very acidic) to 14 (very basic), with 7 being neutral.

calcifying organisms: Marine species that produce calcium carbonate structures, such as corals, mollusks, and some plankton, which are particularly vulnerable to changes in ocean acidity.

carbon sequestration: The process of capturing and storing atmospheric carbon dioxide to mitigate or defer climate change and its impacts.