Master's Student Bo Qin Publishes Research on Responses of Reef-building Corals to Wildfire Emissions in STOTEN

Recently, master's student Bo Qin, under the supervision of associate professor Xiaoyan Chen, published a research paper titled "Responses in reef-building corals to wildfire emissions: heterotrophic plasticity and calcification" in the international journal Science of the Total Environment (JCR Q1) as the first author.

Extreme wildfire events are on the rise globally, and although substantial wildfire emissions may find their way into the ocean, their impact on coral reefs remains uncertain. In a five-week laboratory experiment, Qin and colleagues observed a significant reduction in photosynthesis in coral symbionts (Porites lutea) when exposed to fine particulate matter (PM_2.5) from wildfires. At low PM_2.5 level (2 mg L⁻¹), the changes in δ¹³C and δ¹⁵N values in both the coral host and symbionts suggest reduced autotrophy and the utilization of wildfire particulates as a source of heterotrophic nutrients. This adaptive strategy, characterized by an increase in heterotrophy, sustained some aspects of coral growth (total biomass, proteins and lipids) under wildfire stress. Nevertheless, at high PM_2.5 level (5 mg L⁻¹), both autotrophy and heterotrophy significantly decreased, resulting in an imbalanced coral-algal nutritional relationship. These changes were related to light attenuation in seawater and particulate accumulation on the coral surface during PM_2.5 deposition, ultimately rendering the coral growth unsustainable. Further, the calcification rates decreased by 1.5 to 1.85 times under both low and high levels of PM_2.5, primarily affected by photosynthetic autotrophy rather than heterotrophy.

Qin’s study highlights a constrained heterotrophic plasticity of corals under wildfire stress. This limitation may restrict wildfire emissions as an alternative nutrient source to support coral growth and calcification, especially when oceanic food availability or autotrophy declines, as seen during bleaching induced by the warming ocean.

Item information is

Qin, B., Yu, K., Fu, Y., Zhou, Y., Wu, Y., Zhang, W., Chen, X., 2024. Responses in reef-building corals to wildfire emissions: Heterotrophic plasticity and calcification. Science of The Total Environment 922, 171271. https://doi.org/10.1016/j.scitotenv.2024.171271