Simulation of fluorescence variability in estuaries and DOM

Recent studies have revealed differences between the fluorescence spectra of coastal and open seawater. We investigate here the extent to which abiotic parameters such as pH, ionic strength and concentration of dissolved fluorescent matter could be related to this phenomenon. First, pH effect was addressed alone. Second, a 2 super(3) factorial experimental design was used to estimate the individual and/or combined contribution of the parameters mentioned above to the spectroscopic characteristics of dissolved organic matter represented here by the Suwannee River Fulvic Acid. High pH variations modify the spectroscopic characteristics of organic matter both qualitatively and quantitatively and those effects seem to be related to the dissociation of the major functional groups (e.g. carboxylic and phenolic). General results show that each of the above mentioned parameters affects dissolved fluorescent matter sufficiently to generate slight modifications in its spectral response.