The vertical distribution of the fluorescence of the photosynthetic pigments in Kaliningrad Bay of the Baltic Sea

The annual (2004–2006) series of probing using a multichannel filter-fluorimeter from the water’s surface to the bottom at fixed sites in Kaliningrad Bay and the adjacent areas were carried out. The following parameters were recorded: the water turbidity and temperature, the intensity of the fluorescence of the photosynthetic pigment (excitation at 450 nm, detection band 675–820 nm), and the intensity of the background fluorescence of the dissolved organic matter. The high levels of “red fluorescence” presumably related to the presence of photosynthetic bacterioplankton, live phytoplankton, or their mixture (which demands further biological identification) annually registered in the aphotic zone of the water column represent specific feature of the obtained data.