Ocean Acidification

Ocean acidification (OA) represents one of the most serious long-term threats to coral reef ecosystems and will continue through this century, irrespective of progress in reducing emissions due to the amount of carbon dioxide already in the atmosphere.

Ocean acidification reduces the availability of carbonate ions that are required by many organisms, such as corals and molluscs, to build skeletons and shells. For coral reefs, the most concerning implication of ocean acidification is its effects on coral growth, coralline algae, and rates of chemical erosion of reef substrate which also has significant impacts on dependent fish communities.

Co2 bubbling from the seafloor Sam Noonan AIMS

CO₂ bubbling from the seafloor at a CO₂ seep. Communities naturally living under acidic conditions provide unique perspectives into what coral reefs may look like in the future. Photo © Sam Noonan/Australian Institute of Marine Science

Currently, the best guidance for managing for ocean acidification involves prioritizing management towards protecting natural refugia and managing local stressors on reefs. Management strategies that protect these natural refugia from other stresses may help reefs cope with predicted changes in climate and ocean chemistry.

Management strategies to reduce the impacts of ocean acidification include:

Design MPAs that consider OA
Reduce threats that exacerbate ocean acidification conditions
Explore and apply innovative interventions
Reduce the effects of OA

Resources

NOAA PMEL Carbon Program

The Global Carbon Project

Preparing to Manage Coral Reefs for Ocean Acidification: Lessons from Coral Bleaching

Coral Reef Resilience Online Course, Lesson 6: Management Strategies for Resilience