Yong Luo: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China. ORCID
Xiaolei Yu: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Lintao Huang: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China. ORCID
Jianfeng Gan: South China Institute of Environmental Sciences Ministry of Ecology and Environment of the People's Republic of China Guangzhou China.
Xinming Lei: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Lei Jiang: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China. ORCID
Chengyue Liu: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Youfang Sun: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Meng Cheng: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Yuyang Zhang: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Guowei Zhou: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Sheng Liu: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Jiansheng Lian: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China.
Hui Huang: CAS Key Laboratory of Tropical Marine bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences Guangzhou China. ORCID
Coastal darkening is emerging as a global threat to fringing reefs. While some reef-building corals exhibit resistance to low-light environments, the mechanisms behind this resistance, particularly the role of coral hosts, remain inadequately understood. Here, we investigated variations in underwater photosynthetically active radiation (PAR) and employed the Bayesian stable isotope mixing model (MixSIAR) to estimate the contributions of autotrophic (i.e., dissolved inorganic matter, DIM) and heterotrophic sources (i.e., particulate organic matter, POM, and dissolved organic matter, DOM) to the nutrition of the reef coral on the Luhuitou turbid reef in the northern South China Sea. Our findings revealed that the heterotrophic contribution to coral nutrition increased to 58.5% with decreasing PAR and that the heterotrophic contribution was significantly negatively correlated with δC difference between host and symbiont (δC). Moreover, we observed significant seasonal variations in the respective contributions of POM and DOM to coral nutrition, linked to the sources of these nutrients, demonstrating that can selectively ingest POM and DOM based on their bioavailability to enhance its heterotrophic contribution. This heterotrophic plasticity improved the low-light resistance of and contributed to its prominence within coral communities. However, with a low-light threshold of approximately 3.73% of the surface PAR for , our results underscore the need for effective strategies to mitigate low-light conditions on nearshore turbid reefs. In summary, our study highlights the critical role of heterotrophic plasticity in coral responses to natural low-light environments, suggesting that some reef-building corals with such plasticity could become dominant or resilient species in the context of coastal darkening.
