Ocean acidification exacerbates the inhibition of fluctuating light on the productivity of Ulva prolifera

Zhihai Zhong; Lin Sun; Zhengyi Liu; Zhimin Song; Mengying Liu; Shanying Tong; Song Qin

doi:10.1016/j.marpolbul.2022.113367

Ocean acidification exacerbates the inhibition of fluctuating light on the productivity of Ulva prolifera

Mar Pollut Bull. 2022 Feb:175:113367. doi: 10.1016/j.marpolbul.2022.113367. Epub 2022 Feb 8.

Authors

Zhihai Zhong¹, Lin Sun², Zhengyi Liu³, Zhimin Song⁴, Mengying Liu⁵, Shanying Tong⁶, Song Qin⁷

Affiliations

¹ Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China. Electronic address: zhzhong@yic.ac.cn.
² Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
³ Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
⁴ Zhuhai Central Station of Marine Environmental Monitoring, State Oceanic Administration, Zhuhai 519015, China; Marine Biology Institute, Shantou University, Shantou 515063, China.
⁵ Harbin Institute of Technology, Weihai 264209, China.
⁶ School of Life Sciences, Ludong University, Yantai 264003, China.
⁷ Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China. Electronic address: sqin@yic.ac.cn.

PMID: 35149313
DOI: 10.1016/j.marpolbul.2022.113367

Abstract

Ulva prolifera, a common species of green macroalgae, is often harmful-algal-bloom causative and significantly impacts local marine ecosystems. Previous studies on the physiological characteristics of U. prolifera have been conducted under constant light (CL). However, light in the natural environment continually changes, and little is known about fluctuating light (FL). Ocean acidification (OA) has been proposed to interact with dynamic surrounding environments to affect the physiological performance of macroalgae. Therefore, we investigated the combined effects of FL (80/300, alternating between 80 μmol photons m^-2 s^-1 for 2.5 h and 300 μmol photons m^-2 s^-1 for 1.5 h, with an average light intensity of 160 μmol photons m^-2 s^-1 and OA (1000 ppm CO₂) on U. prolifera. The results clearly showed that FL had no significant effect on the relative growth rate (RGR), whereas OA obviously improved RGR. However, under FL-OA combination conditions, RGR was inhibited significantly, accompanied by a concomitant downgraded photosynthetic performance, while the photoprotective abilities were enhanced. The results would help us accurately predict the primary productivity of macroalgae in coastal waters under future OA conditions with irradiance fluctuations.

Keywords: Fluctuating light; Ocean acidification; Photoprotective mechanism; Photosynthetic performance.

MeSH terms

Ecosystem
Hydrogen-Ion Concentration
Oceans and Seas
Seawater
Ulva*