Coral mucus input promotes sedimentary organic matter degradation: Evidence from a typical coral reef area, northern South China Sea

Bo Yang ¹, Bin Yang ², Lei Xie ¹

¹Key Laboratory of Coastal Salt Marsh Ecosystems and Resources, Ministry of Natural Resources/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Guangxi Key Laboratory of Beibu Gulf Marine Resources, Environment and Sustainable Development, Beihai, 536015, China; Jiangsu Key Laboratory of Marine Genetic Resources and Breeding, Jiangsu Ocean University, Lianyungang, China.
²Key Laboratory of Coastal Salt Marsh Ecosystems and Resources, Ministry of Natural Resources/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Guangxi Key Laboratory of Marine Environmental Disaster Processes and Ecological Protection Technolog, College of Marine Sciences, Beibu Gulf University, Qinzhou 535011, China; Jiangsu Key Laboratory of Marine Genetic Resources and Breeding, Jiangsu Ocean University, Lianyungang, China; Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China.
³Guangxi Key Laboratory of Marine Environmental Disaster Processes and Ecological Protection Technolog, College of Marine Sciences, Beibu Gulf University, Qinzhou 535011, China.
⁴Editorial Department of Journal of Jiangsu Ocean University, Lianyungang 222005, China.
⁵Guangxi Key Laboratory of Marine Environmental Disaster Processes and Ecological Protection Technolog, College of Marine Sciences, Beibu Gulf University, Qinzhou 535011, China; Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China.
⁶Guangxi Key Laboratory of Marine Environmental Disaster Processes and Ecological Protection Technolog, College of Marine Sciences, Beibu Gulf University, Qinzhou 535011, China; Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
⁷Key Laboratory of Coastal Salt Marsh Ecosystems and Resources, Ministry of Natural Resources/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Jiangsu Key Laboratory of Marine Genetic Resources and Breeding, Jiangsu Ocean University, Lianyungang, China.

⁰Key Laboratory of Coastal Salt Marsh Ecosystems and Resources, Ministry of Natural Resources/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Guangxi Key Laboratory of Beibu Gulf Marine Resources, Environment and Sustainable Development, Beihai, 536015, China; Jiangsu Key Laboratory of Marine Genetic Resources and Breeding, Jiangsu Ocean University, Lianyungang, China.

Environmental Research +

|

January 15, 2026

View abstract on PubMed

Summary

Coral mucus significantly alters ocean sediment organic matter dynamics by fueling microbial metabolism. This process accelerates the breakdown of both mucus and native organic matter, impacting carbon cycling in reef ecosystems.

Area Of Science

Marine biogeochemistry
Coral reef ecology
Sedimentary processes

Background

Global warming and human activities increase coral mucus release.
Coral mucus transport to sediments alters sedimentary organic matter (SOM) dynamics.
Mechanisms of mucus impact on SOM remain poorly understood.

Purpose Of The Study

Investigate how coral mucus regulates organic matter (OM) transport and storage in reef sediments.
Determine the role of mucus in OM dynamics in the South China Sea.
Elucidate the mechanisms of mucus-mediated OM alteration.

Main Methods

Integrated field surveys in a South China Sea coral reef.
Laboratory incubations with mucus-amended and control sediment groups.
130-day microbial degradation experiments to assess OM reactivity.

Main Results

Reef sediments showed lower porewater dissolved organic carbon (DOC) and SOM content but higher biological reactivity than non-reef sediments.
Mucus amendment significantly increased DOC and SOM degradation rates compared to controls.
Coral mucus-derived DOC was highly labile, stimulating remineralization of ambient OM via priming.

Conclusions

Coral mucus acts as a microbially activated biogeochemical engine in reef sediments.
Mucus bioavailability fuels microbial metabolism, accelerating native OM turnover.
Mucus plays a critical role in regulating OM dynamics and carbon storage in coral reef environments.

Keywords:

Coral mucus Coral reef Microbial degradation Priming effect Sedimentary organic matter

Related Concept Videos

Primary Production

The total amount of energy acquired by primary producers in an ecosystem is called gross primary production (GPP). However, of this energy, producers use some for metabolic processes, and some is lost as heat, decreasing the amount of energy available to the next trophic level. The remaining usable amount of energy is called the net primary productivity (NPP). In terrestrial ecosystems, NPP is driven by climate, while light penetration and nutrient availability drive NPP in aquatic ecosystems.