reefhealth

Reef health describes the overall condition of coral reef ecosystems, including biological integrity, structural complexity, and the capacity to provide ecosystem services. A healthy reef typically features high live coral cover, diverse coral and fish communities, balanced macroalgae levels, robust recruitment, and low incidence of disease and bleaching. Key indicators include coral cover percentage, recruitment rates, species richness, coral morphology variety, algal dominance, herbivore populations, disease prevalence, and signs of bleaching or structural damage.

Reef health is influenced by environmental drivers such as water temperature, acidity, sedimentation, nutrient levels, and pollution, as well as biological pressures like overfishing, invasive species, and disease outbreaks. Anthropogenic stressors from climate change pose major threats through thermal stress and ocean acidification, which reduce calcification and disrupt symbiosis with zooxanthellae.

Assessment methods combine field surveys (line transects, belt transects, photomonitoring), remote sensing, and bioindicators like zooxanthellae density. Long-term monitoring is essential due to natural variability and episodic events.

Management actions aim to maintain or improve reef health by reducing local stressors (pollution control, sustainable fisheries, fishing restrictions, reef protection areas), restoring damaged habitat (coral gardening, larval propagation), and enhancing resilience through connectivity and protected networks. Understanding reef health supports conservation planning, fisheries management, and climate adaptation efforts.