A collaborative research team led by The Hong Kong University of Science and Technology (HKUST), the Institute of Zoology at the Chinese Academy of Sciences (IOZ-CAS) and the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (GML) has revealed the long-overlooked carbon storage potential of coral reef ecosystems and how reef-dwelling fish, corals, and surface sediments jointly shape reef carbon reservoirs.
Coral reefs, despite being among the most diverse and productive marine ecosystems, remain poorly characterized in terms of their carbon reservoirs. To address this knowledge gap, the research team—led by Prof. QIAN Peiyuan, Chair Professor of the Department of Ocean Science at HKUST; Prof. WEI Fuwen from IOZ-CAS and Prof. ZHOU Wenliang, a researcher at GML —developed a new method incorporating stereo-video surveys, elemental analysis, and statistical modeling to quantify carbon reservoirs in South China Sea (SCS) coral reef ecosystems, including carbon stored in reef fish, coral communities, and sediments.
The results revealed that the estimated carbon storage of SCS coral reefs was nearly equivalent to, if not exceeding, the carbon reservoirs in the country's blue carbon ecosystems (mangroves, salt marshes, and seagrass beds), which have long been thought to be critical for global climate mitigation. Sediment was found to be the dominant carbon pool, while coral and fish biomass also contributed to the carbon stock. This key finding indicates that the degradation of coral reef ecosystems is likely to reduce their carbon storage capacity and ultimately lead to the release of previously sequestered carbon into the ocean and atmosphere.
The team also systematically analyzed the contributions of reef-dwelling organisms to carbon fixation, transformation, and release. By compiling research results from over 50 studies in global coral reef hotspots, researchers identified a positive trend in both net calcification and net production at the ecosystem level, indicating the dynamic and complex carbon exchange and redistribution in coral reef ecosystems.
Furthermore, the study examined the impact of reef fish on the carbon cycle of coral reefs through pathways such as bioerosion, excretion, and respiration. Surprisingly, the influence of fish assemblages on the carbon budget was found to far exceed their direct carbon storage capacity. Fish are estimated to transport a relatively large amount of carbon into the sediment carbon reservoir each year. The magnitude of these contributions highlights a key ecological insight: conserving reef animal populations is not only critical for biodiversity but also essential for sustaining the pivotal role of sediments as long-term carbon reservoirs in coral reef ecosystems.
Prof. Qian Peiyuan said, “Our study demonstrates the significant carbon sequestration potential of coral reef ecosystems, using SCS reefs as an example, and provides critical insights into the role of corals and reef-dwelling fish in coral reef carbon cycling. These findings highlight the necessity of biodiversity conservation amid increasingly severe global changes, specifically to maintain the carbon sequestration function and stability of coral reef ecosystems.”
This research was supported by the Ministry of Science and Technology of China, the Science and Technology Department of Guangdong Province, the Guangdong Forestry Administration, the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), the HKSAR Government, and the HKUST Otto Poon Center for Climate Resilience and Sustainability.
The research findings were published in the top-tier interdisciplinary journal Advanced Science . The paper is co-corresponding by Prof. QIAN Pei-Yuan, Prof. WEI Fuwen, and Prof. ZHOU Wenliang, while CHEN Yiting, a joint PhD candidate at HKUST and GML, is the first author.
Advanced Science
Data/statistical analysis
Lab-produced tissue samples
Corals and Reef-Dwelling Fish Regulate Carbon Storage and Cycling Processes in Coral Reef Ecosystems
17-Apr-2026