Fig. 1. A - Absorption spectrum of phytoplankton suspension from central area of the Baltic Sea. Values of absorption coefficients are averaged over spectral regions 400-550 nm (afl) and 400-700 nm (a_S).

B - Spectrum of the light used to excite chlorophyll fluorescence in PrimProd fluorometer (1), and spectral distribution of underwater illumination in clear water at depths of 1 (2), 5 (3), and 20 m (4).

Fig. 2. Histograms of km (A) and I_1/2m (B) distribution, obtained at the stations of Baltic Sea.