Journal of East China Normal University(Natural Science) ›› 2023, Vol. 2023 ›› Issue (3): 108-117.doi: 10.3969/j.issn.1000-5641.2023.03.011

• Estuary and Coastal Research • Previous Articles    

Growth response of Heterosigma akashiwo to the changes of CO2 concentration, temperature and nutrient

Anqiang YANG1, Lixia ZHAO2,3, Shuzhen SONG1, Jie LIU4, Yanlong HE2,5, Yanna WANG1,*()   

  1. 1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
    2. East China Sea Environmental Monitoring Center, State Oceanic Administration, Shanghai 201206, China
    3. East China Sea Ecological Center, the Ministry of Natural Resources, Shanghai 201206, China
    4. Department of Biological Sciences, University of Bergen, Bergen N-5020, Norway
    5. Yangtze Delta Estuarine Wetland Ecosystem Observation and Research Station, Ministry of Education & Shanghai Science and Technology Committee, Shanghai 202162
  • Received:2021-07-26 Accepted:2021-10-09 Online:2023-05-25 Published:2023-05-25
  • Contact: Yanna WANG E-mail:ynwang@sklec.ecnu.edu.cn

Abstract:

Heterosigma akashiwo is one of the species of harmful algal blooms (HABs) threatening marine ecosystems and the fishing industry across coastal waters worldwide. With increasing global levels of atmospheric CO2 and global warming, HABs have increased in prevalence, duration, and geographic span; this phenomenon has been further stressed by intensified anthropogenic influences, such as eutrophication. Through controlled experiments with different nutrients, CO2 concentrations, and temperatures, our study aimed to understand the response of H. akashiwo to different nutrients with changes in climate. In all simulated CO2 and temperature scenarios, both cell density and the specific growth rate of H. akashiwo in the low phosphorus groups were significantly lower than those in the high phosphorus groups. Furthermore, the maximum cell density and specific growth rate of H. akashiwo were significantly enhanced by increased CO2, while the specific growth rate was accelerated by the dual effect of increased CO2 levels and temperature. The growth response of H. akashiwo to CO2 and temperature was similar between different nutrient treatments. Taken together, the results indicate that phosphorus concentration could be the major factor controlling the growth of H. akashiwo, and the intensity and risk of H. akashiwo blooming in the future is increasing. Hence, controlling the increase of nutrients, particularly phosphate, could be a critical pathway to decrease the occurrence of H. akashiwo blooms. In summary, our case study provides scientific support for marine ecological management of HABs.

Key words: harmful algal blooms, Heterosigma akashiwo, CO2 concentration, warming, nutrient

CLC Number: