AB 7:59-70 (2009)  -  DOI: https://doi.org/10.3354/ab00182

Effects of carbon dioxide on the coccolithophorid Pleurochrysis carterae in incubation experiments

Beatriz E. Casareto1,2,*, Mohan P. Niraula2,4, Hiroyuki Fujimura3, Yoshimi Suzuki2

1Laboratory of Aquatic Science and Consultant Co., Ltd., Meishin Bldg. Kamiikedai 1-14-1, Ota-ku, Tokyo 145-0064, Japan
2Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
3Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan
4Institute of Science and Technology, Tribhuvan University Trichandra Campus, Kathmandu, Nepal

ABSTRACT: Production (abundance and biomass) and net calcification rates of the coccolithophorid Pleurochrysis carterae under different partial pressures of CO2 (pCO2) were examined using short (15, 24 and 39 h), long (7 d) and dark (7 d) incubation experiments. Short incubations were conducted at ambient, 500 and 820 ppm pCO2 levels in natural seawater that was enriched with nutrients and inoculated with P. carterae. Long incubations were conducted at ambient and 1200 ppm pCO2 levels in natural seawater (0.2 µm filtered as well as unfiltered) that was enriched with nutrients and inoculated with P. carterae. Dark incubations were conducted at ambient and 1200 ppm pCO2 in unfiltered seawater that was inoculated with P. carterae. The abundance and biomass of coccolithophorids increased with pCO2 and time. The abundance and biomass of most noncalcifying phytoplankton also increased, and were hardly affected by CO2 inputs. Net calcification rates were negative in short incubations during the pre-bloom phase regardless of pCO2 levels, indicating dissolution of calcium carbonate. Further, the negative values of net calcification in short incubations became less negative with time. Net calcification rates were positive in long incubations during blooms regardless of pCO2 level, and the rate of calcification increased with pCO2. Our results show that P. carterae may adapt to increased (~1200 ppm) pCO2 level with time, and such increase has little effect on the ecology of noncalcifying groups and hence in ecosystem dynamics. In dark incubations, net calcification rates were negative, with the magnitude being dependent on pCO2 levels.


KEY WORDS: pCO2 · Pleurochrysis carterae · Noncalcifying phytoplankton · Biomass · Net calcification rates · Adaptation


Full text in pdf format  
Cite this article as: Casareto BE, Niraula MP, Fujimura H, Suzuki Y (2009) Effects of carbon dioxide on the coccolithophorid Pleurochrysis carterae in incubation experiments. Aquat Biol 7:59-70. https://doi.org/10.3354/ab00182

Export citation
Mail this link - Contents Mailing Lists - RSS
- -