Evidence for a simple relationship between natural fluorescence, photosynthesis and chlorophyll in the sea

In vivo measurements of the seasonal photosynthetic fluorescence of the Mediterranean coral <i>Cladocora caespitosa</i> (L.)

“…Though the evaluation of true photosynthetic yield from INF-300 measurements proved to be very difficult (Chamberlin et al, 1990;Maritonema et al, 1990), the measurements on Cladocora caespitosa confirmed that photosynthesis occurs in the coral even in winter months, when turbidity may reduce light penetration to a minimum.…”

“…Natural chlorophyll a (Chl a) fluorescence was measured using an INF-300 Integrating Natural Fluorometer (Biospherical Instrument Inc.), a device used to measure in vivo phytoplankton fluorescence (Chamberlin et al, 1990). The system has a detector arranged to record natural upwelling radiance of a water mass, filtering the emission spectra of Chl a and rejecting wavelengths of less than 650 nm.…”

Estimates of Indian Ocean productivity using natural fluorescence

“…It has been used as a means of assessing the distribution and biomass of oceanic phytoplankton, and most recently for the estimation of rates of gross primary production. T h e level of natural fluorescence is related to the rate of light absorption by Photosystem 11, and calculations of GPP a r e based upon t h e assumption that the ratio of photosynthetic to fluorescence yields is a predictable function of light intensity (Kiefer et a1 1989, Chamberlain et al 1990). This new method is a passive, in-situ technique that does not interfere with the natural metabolism of the plankton and thus could possibly generate estimates of production that are different from those generated by traditional methodologies which rely on enclosed incubations.…”

“…to signify the instantaneous nature of the measurement (refer to Chamberlain et al 1990). Estimates of integrated water column GPP were calculated using the depth-binned data (0-130m) which was normalized to the average surface irradiance of all casts and then combined with dawn-to-dusk sunlight data recorded during a coral observation experiment t o provide estimates of daily water column production (mg~-m-2.day"), Vertical profiling casts were camed out by hand lowering the instrument from a platform located on the port side of the ship approximately 2 m above the sea surface.…”

“…The reader is referred to Chamberlain et al 1990 1-7-1989 1734 scans P r o f i l e ended: 01-07-1989 14:32:12 U n i t s are meters, PAR: uE/m2, kPAR:l/meters, Temp Degrees C. D i f f u s e attenuation c o e f f i c i e n t f o r PAR (~~a t -1 i n l/meters, 15 p o i n t smooth. Natural Fluorescence i n nE/m2/s/str from chlorophyll, Producted production i n nM carbon/d/sec.…”