Marine Invertebrates and Coral Reef Health: A Review

Coral reefs, often referred to as the “rainforests of the sea,” are among the most biodiverse ecosystems on Earth. At the heart of this diversity are marine invertebrates, which include a vast array of taxa such as mollusks, echinoderms, crustaceans, sponges, and cnidarians. These organisms play pivotal roles in nutrient cycling, bioerosion, and reef construction and maintenance. However, coral reefs are in rapid decline due to anthropogenic stressors such as climate change, ocean acidification, pollution, and overfishing. This review explores the intricate ecological relationships between marine invertebrates and coral reefs, highlighting the functional significance of invertebrate biodiversity in maintaining reef resilience and health. It discusses key threats to these organisms, including coral bleaching, disease outbreaks, and habitat degradation. The review synthesizes findings from recent ecological studies, physiological experiments, and longterm monitoring programs to present a comprehensive understanding of the feedback loops that either stabilize or destabilize reef ecosystems. In particular, the interactions between invertebrate herbivores and coral-algal dynamics are examined, as they are central to coral recruitment and reef recovery. The paper concludes with an analysis of current conservation practices, including marine protected areas (MPAs), assisted evolution, and reef restoration efforts, while identifying gaps in research that must be addressed to ensure the future of coral reef ecosystems. This review underscores the urgent need for integrated, ecosystem-based approaches to conservation that prioritize the symbiotic roles of marine invertebrates in sustaining coral reef health.