Jukka Seppälä
Tvärminne
Zoological Station, FIN-10900 Hanko, Finland
and
Finnish Environment Institute, P.O. Box 140, FIN-00251 Helsinki, Finland
Precise detection, and prediction of phytoplankton blooms is a present day challenge for ecological studies of the Baltic Sea. Optical approaches, ranging from single cell measurements to satellite observations, are widely utilized for approximation of the bulk phytoplankton biomass. However, the information of distinct phytoplankton species - or groups - is often required, and that lays an extra challenge for both instrumentation and optical models.
It has been suggested by several authors that the in vivo fluorescence of phycobilins can be used for the tracking the distribution of cyanobacteria. In the Baltic Sea the origins of phycobilin fluorescence are, however, multiple, and thus a straightforward conversion of cyanobacterial bloom intensity from the phycobilin fluorescence reading is an impossible task.
In this poster I present a theoretical background for the detection of algae by spectral fluorescence, with a special emphasis on the detection of cyanobacteria by phycobilin fluorescence. The pigmentation and fluorescence properties of phycobilin containing species in the Baltic Sea are shortly reviewed. Further, fluorescence spectra measured from pure algal cultures are compared with the spectra measured from the natural water samples. As an example; the variability in phycobilin fluorescence during cyanobacterial bloom in the Baltic Sea is shown. To conclude, different methodological approaches for measuring phycobilin fluorescence are compared.