Proceedings PaperSpectral transformation of downwelling radiation by autofluorescent organisms in the sea
|Format||Member Price||Non-Member Price|
The fluorescence emission (685 nm) from chlorophyll in phytoplankton makes a measurable contribution to the upwelling light in the sea. The emissions from other autofluorescing biological sources are not as well described. The photosynthetic accessory pigments (phycoerythnn and phycocyanin) comprise just one additional group of fluorescent substances. Many micro- and macroscopic heteroirophic marine organisms exhibit autofluorescent responses to incident radiation over all or part of their surfaces. The intensity may vary widely, and emission wavelengths span the whole visible spectrum. This paper will present microspectrofluorometric measurements of the fluorescence emission from a variety of marine subjects, ranging from single-celled members of the plankton community to both planktonic and attached invertebrates. As modeling of the underwater light field is refined to greater levels of detail there is a need for information on the precise wavelengths of fluorescence emission that might be introduced by biological sources, and on the abundance and distribution of those sources. The existing catalogue of observations of such sources is influenced by the constraints of epifluorescence microscopy and the widespread use of filter sets designed for optimal detection of chlorophyll. With appropriate measurement technique these limitations can be avoided and the catalogue expanded.