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Measurement of phytoplankton photosynthesis rate using a pump-and-probe fluorometer

100%

Antal T. K., Venediktov P. S., Matorin D. N., Ostrowska M., Wozniak B., Rubin A. B.

Oceanologia

2001

tom 43

nr 3

291-313

In this work we have studied the possibility of determining the rate of phytoplankton photosynthesis in situ using a submersible pump-and-probe fluorometer in water areas differing in their trophic level, as well as in climatic and hydrophysical characteristics. A biophysical model was used to describe the relationship between photosynthesis, underwater irradiance, and the intensity of phytoplankton fluorescence excited by an artificial light source. Fluorescence intensity was used as a measure of light absorption by phytoplankton and for assessing the efficiency of photochemical energy conversion at photosynthetic reaction centers. Parameters of the model that could not be measured experimentally were determined by calibrating fluorescence and irradiance data against the primary production measured in the Baltic Sea with the radioactive carbon method. It was shown that the standard deviation of these parameters in situ did not exceed 20%, and the use of their mean values to estimate the phytoplankton photosynthetic rate showed a good correlation between the calculated and measured data on primary production in the Baltic (r = 0.89), Norwegian (r = 0.77) and South China (r = 0.76) Seas.

Chlorophyll fluorimetry as a method for studying light absorption by photosynthetic pigments in marine algae

100%

Matorin D. N., Antal T. K., Ostrowska M., Rubin A. B., Ficek D., Majchrowski R.

Oceanologia

2004

tom 46

nr 4

Using laboratory cultures of algae and natural phytoplankton populations from Nhatrang Bay (South China Sea), the relationship between the chlorophyll fluorescence F0, the chlorophyll a concentration Ca and light absorption capacities of algae cells was studied. It is shown that the ratio F0/Ca depends mainly on the species composition of the algae population; hence, the concentration Ca can be measured with the fluorescence method with acceptable accuracy only when the species composition of algae populations varies over a rather narrow range. The fluorescence F0 can, however, be a good index of the total absorption capacities of different phytoplankton species, because the intensity of F0 depends on the sum total of light absorbed by all photosynthetic pigments in a plant cell. Thus, the fluorescence F0 measures not only the concentration of chlorophyll a, but that of all photosynthetic pigment concentrations.

Ograniczanie wyników

2 Oceanologia

2 Antal T. K.

2 Matorin D. N.

2 Ostrowska M.

2 Rubin A. B.

1 Ficek D.

1 Majchrowski R.

1 Venediktov P. S.

1 Wozniak B.

1 2004

1 2001

Wyniki wyszukiwania

Measurement of phytoplankton photosynthesis rate using a pump-and-probe fluorometer

Chlorophyll fluorimetry as a method for studying light absorption by photosynthetic pigments in marine algae