Functionally diverse reef-fish communities ameliorate coral disease

Area of Science:

• Marine biology
• Ecology
• Conservation science

Background:

• Coral reefs face unprecedented degradation, with diseases increasingly recognized as a major driver of mortality.
• Understanding factors influencing coral disease occurrence and spread is crucial for ecosystem resilience.
• Overfishing reduces functional diversity in reef ecosystems, potentially exacerbating coral health issues.

Purpose of the Study:

• To test the hypothesis that reefs with diverse fish communities exhibit less coral disease compared to overfished reefs.
• To investigate the relationship between fish trophic diversity and coral disease prevalence.
• To assess the role of marine protected areas (MPAs) in mitigating coral disease.

Main Methods:

• Surveys of coral reefs in the central Philippines and the Great Barrier Reef.
• Assessment of coral disease prevalence and reef fish taxonomic and trophic diversity.
• Statistical correlation analysis between fish diversity metrics and coral disease rates.

Main Results:

• Coral disease prevalence was significantly negatively correlated with fish taxonomic diversity.
• Marine protected areas (MPAs) showed higher fish diversity and lower coral disease rates than unprotected areas.
• Density of coral-feeding butterflyfish (Chaetodontidae) was positively associated with coral disease prevalence.

Conclusions:

• Trophic diversity of reef fish communities plays a significant role in regulating coral disease.
• Overfishing, particularly impacting coral-feeding fish, may increase coral disease susceptibility.
• Conservation strategies promoting fish diversity, especially within MPAs, are vital for coral reef health.