Ocean Acidification Impacts to Know for Intro to Climate Science

Ocean acidification is a major consequence of climate change, impacting marine life and ecosystems. It affects calcification, coral health, and biodiversity, leading to weakened food webs and economic challenges for fisheries, ultimately threatening the balance of ocean environments.

1. Decreased calcification rates in marine organisms

   • Ocean acidification reduces the availability of carbonate ions, essential for calcification.
   • Organisms like corals, mollusks, and some plankton struggle to build and maintain their calcium carbonate structures.
   • Weaker shells and skeletons lead to increased vulnerability to predation and environmental stress.

2. Coral reef degradation and bleaching

   • Lower pH levels stress coral polyps, leading to the expulsion of symbiotic algae (zooxanthellae).
   • Bleached corals lose their color and essential energy sources, resulting in higher mortality rates.
   • Degraded reefs lose biodiversity and the protective habitat they provide for numerous marine species.

3. Shellfish and pteropod shell dissolution

   • Increased acidity directly affects the shells of shellfish and pteropods, causing them to dissolve.
   • This dissolution threatens the survival of species that are crucial for marine food webs and human consumption.
   • The loss of these organisms can disrupt ecological balance and food availability for higher trophic levels.

4. Altered marine food webs and ecosystems

   • Changes in species composition and abundance can disrupt predator-prey relationships.
   • Key species declines can lead to cascading effects throughout the food web, impacting overall ecosystem health.
   • Altered nutrient cycling and energy flow can result from shifts in species interactions.

5. Reduced biodiversity in marine environments

   • Ocean acidification disproportionately affects sensitive species, leading to population declines and extinctions.
   • Loss of biodiversity reduces ecosystem resilience and the ability to adapt to environmental changes.
   • Ecosystems with lower biodiversity are less productive and more vulnerable to disturbances.

6. Impacts on fish behavior and sensory abilities

   • Ocean acidification can impair fish sensory systems, affecting their ability to detect predators and prey.
   • Altered behaviors, such as reduced foraging efficiency and increased risk-taking, can lead to population declines.
   • Changes in fish behavior can disrupt reproductive success and community dynamics.

7. Changes in phytoplankton composition and productivity

   • Ocean acidification can favor certain phytoplankton species over others, altering community structure.
   • Changes in phytoplankton productivity can impact the entire marine food web, as they are primary producers.
   • Shifts in phytoplankton can affect carbon cycling and nutrient availability in marine ecosystems.

8. Potential economic impacts on fisheries and aquaculture

   • Declines in shellfish and fish populations can lead to reduced catches and economic losses for fisheries.
   • Aquaculture operations may face challenges in maintaining healthy stocks due to shell dissolution and disease.
   • Economic impacts can extend to coastal communities reliant on fishing and tourism.

9. Altered ocean carbon cycle and CO2 absorption capacity

   • Ocean acidification affects the ocean's ability to absorb atmospheric CO2, potentially exacerbating climate change.
   • Changes in carbonate chemistry can influence the biological pump, which sequesters carbon in the deep ocean.
   • A less effective carbon sink can lead to higher atmospheric CO2 levels and further climate impacts.

10. Synergistic effects with other stressors like warming and deoxygenation

    • Ocean acidification interacts with rising temperatures and reduced oxygen levels, compounding stress on marine life.
    • Combined stressors can lead to more severe impacts on species survival and ecosystem health.
    • Understanding these interactions is crucial for predicting future changes in marine environments.