Skeleton-Forming Responses of Reef-Building Corals under Ocean Acidification.

Area of Science:

• Marine Biology
• Coral Reef Ecology
• Oceanography

Background:

• Ocean acidification is a growing threat to coral reefs globally.
• Limited understanding of how reduced pH affects coral skeleton formation hinders conservation efforts.

Purpose of the Study:

• To investigate the impact of simulated ocean acidification on the skeleton-forming strategies of major reef-building corals.
• To analyze changes in skeletal density, elemental composition, and gene expression under reduced pH conditions.

Main Methods:

• Studied four widely distributed coral species in a simulated acidified habitat (pH 7.6–7.8).
• Reconstructed and visualized coral skeleton formation processes.
• Quantified elemental calcium loss and analyzed gene expression changes.

Main Results:

• Coral species display diverse skeletal responses to lower pH.
• Acropora muricata exhibits a "cavity-like" internal formation, sacrificing density to protect polyps.
• Pocillopora damicornis, Montipora capricornis, and Montipora foliosa showed "osteoporosis"-like changes: disordered structures, reduced adhesion proteins, and low bone mass.
• Acidification particularly damages pre-existing coral skeletons.

Conclusions:

• Findings reveal varied skeleton-forming strategies in corals facing ocean acidification.
• This research provides crucial insights for coral reef protection and restoration strategies.
• Understanding species-specific responses is vital for mitigating the effects of increasing ocean acidity on reef ecosystems.