Enhancing reef carbonate budgets through coral restoration

Area of Science:

• Marine biology
• Coral reef ecology
• Restoration science

Background:

• Coral reefs provide essential ecosystem services but are declining due to stressors like ocean warming and disease.
• Florida Reef Tract (US) is experiencing net reef framework loss with erosion exceeding accretion.
• Traditional coral restoration success metrics focus on coral survival and growth, not reef accretion.

Purpose of the Study:

• To empirically assess the role of high-density outplants of staghorn coral (Acropora cervicornis) in restoring positive carbonate accretion on Florida reefs.
• To determine the coral cover threshold required for staghorn coral restoration to achieve net positive carbonate production.

Main Methods:

• Conducting an empirical study on Florida reefs using high-density outplants of Acropora cervicornis.
• Comparing net carbonate production rates between restored plots and control plots.
• Quantifying the relationship between coral cover and net carbonate production in restored areas.

Main Results:

• Successful transplantation of staghorn corals resulted in positive net carbonate production.
• Restored plots achieved a mean net carbonate production rate of 3.06 kg CaCO3 m-2 yr-1.
• A coral cover threshold of approximately 2.96% was sufficient to sustain positive net carbonate production in restored plots, while control plots showed net erosion.

Conclusions:

• High-density outplanting of Acropora cervicornis can restore positive carbonate accretion on degraded reefs.
• Coral restoration efforts must consider resilience to environmental stressors like bleaching, storms, and disease.
• Establishing Acropora aggregations through outplanting, combined with climate adaptation, can promote reef habitat growth and ecosystem service recovery.