The fluorescence of the Black Sea and the Rhodes Gyre, Eastern Mediterranean

Determinations of the ultra violet-visible fluorescence of sea water carefully sampled from precise locations and depths in the Black Sea and the eastern Mediterranean in 1991/1992 are described. Parameters controlling the reproducibility and resolution of the spectra are emphasised and the rst fluorescence lifetimes of sea water are recorded. The best excitation spectra are obtained when the emission wavelength is 440 nm; the best emission spectra are given with an excitation wavelength of 220-230 nm, and the best synchronous spectra require a of 50 nm. The contributions of humic acids, aromatic amino acids, carotenoids and flavins to the fluorescence spectra are discussed in detail but the fluorescence of chlorophyll has been ignored. Flowing Black Sea and eastern Mediterranean sea waters can be characterised by their fluorescence in the ultra violet and further studies of fluorescence may in future provide information as to the composition of the dissolved organic constituents.