2Author for correspondence and present address: Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan. e-mail firstname.lastname@example.org.
THE ELEMENTAL COMPOSITION OF SOME MARINE PHYTOPLANKTON1
Version of Record online: 24 NOV 2003
Journal of Phycology
Volume 39, Issue 6, pages 1145–1159, December 2003
How to Cite
Ho, T.-Y., Quigg, A., Finkel, Z. V., Milligan, A. J., Wyman, K., Falkowski, P. G. and Morel, F. M. M. (2003), THE ELEMENTAL COMPOSITION OF SOME MARINE PHYTOPLANKTON. Journal of Phycology, 39: 1145–1159. doi: 10.1111/j.0022-3646.2003.03-090.x
1Received 9 May 2003. Accepted 4 September 2003.
- Issue online: 24 NOV 2003
- Version of Record online: 24 NOV 2003
- culture medium;
- elemental composition;
- marine phytoplankton;
- Redfield ratio;
- trace elements;
- trace metals;
- trace nutrients
We analyzed the cellular content of C, N, P, S, K, Mg, Ca, Sr, Fe, Mn, Zn, Cu, Co, Cd, and Mo in 15 marine eukaryotic phytoplankton species in culture representing the major marine phyla. All the organisms were grown under identical culture conditions, in a medium designed to allow rapid growth while minimizing precipitation of iron hydroxide. The cellular concentrations of all metals, phosphorus, and sulfur were determined by high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS) and those of carbon and nitrogen by a carbon hydrogen nitrogen analyzer. Accuracy of the HR-ICPMS method was validated by comparison with data obtained with 55Fe radioactive tracer and by a planktonic reference material. The cellular quotas (normalized to P) of trace metals and major cations in the biomass varied by a factor of about 20 among species (except for Cd, which varied over two orders of magnitude) compared with factors of 5 to 10 for major nutrients. Green algae had generally higher C, N, Fe, Zn, and Cu quotas and lower S, K, Ca, Sr, Mn, Co, and Cd quotas than coccolithophores and diatoms. Co and Cd quotas were also lower in diatoms than in coccolithophores. Although trace element quotas are influenced by a variety of growth conditions, a comparison of our results with published data suggests that the measured compositions reflect chiefly the intrinsic (i.e. genetically encoded) trace element physiology of the individual species. Published field data on the composition of the planktonic biomass fall within the range of laboratory values and are generally close to the approximate extended Redfield formula given by the average stoichiometry of our model species (excluding the hard parts):
While clearly this elemental stoichiometry varies between species and, potentially, in response to changes in the chemistry of seawater, it provides a basis for examining how phytoplankton influence the relative distributions of the ensemble of major and trace elements in the ocean.