Action spectrum and maximum quantum yield of carbon fixation in natural phytoplankton populations: Implications for primary production estimates in the ocean

• Published in: Journal of Marine Systems
• Main Authors: Arbones, Belén, Figueiras, F. G., Varela, Ramiro
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2000
• Subjects: Maximum quantum yield; Carbon; Phytoplankton; Austral; Gerlache; Gerlache Strait; Antarc*
• Online Access: http://hdl.handle.net/10261/57158; https://doi.org/10.1016/S0924-7963(00)00042-7

18 páginas, 10 figuras, 1 tabla Spectral and non-spectral measurements of the maximum quantum yield of carbon fixation for natural phytoplankton assemblages were compared in order to evaluate their effect on bio-optical models of primary production. Field samples were collected from two different coastal regions of NW Spain in spring, summer and autumn and in a polar environment Gerlache Strait, Antarctica.during the austral summer. Concurrent determinations were made of spectral phytoplankton absorption coefficient waph l.x, white-light-limited slope of the photosynthesis–irradiance relationships a B., carbon uptake action spectra waB l.x, broad-band maximum quantum yields fm., and spectral maximum quantum yields wfm l.x. Carbon uptake action spectra roughly followed the shape of the corresponding phytoplankton absorption spectra but with a slight displacement in the blue–green region that could be attributed to imbalance between the two photosystems PS I and PS II. Results also confirmed previous observations of wavelength dependency of maximum quantum yield. The broad-band maximum quantum yield fm.calculated considering the measured spectral phytoplankton absorption coefficient and the spectrum of the light source of the incubators was not significantly different form the averaged spectral maximum quantum yieldwf l.x t-test for paired samples, Ps0.34. These results suggest that maximum quantum yield can be estimated max with enough accuracy from white-light P–E curves and measured phytoplankton absorption spectra. Primary production at light limiting regimes was compared using four different models with a varying degree of spectral complexity. No significant differences t-test for paired samples, Ps0.91.were found between a spectral model based on the carbon uptake action spectra waB l. — model ax and a model which uses the broad-band fmand measured aph l. model b. In addition, primary production derived from constructed action spectra waBc l. from aph l. and a B model c. was also not significantly ...