Biomonitoring urban fluvial contamination on the basis of physiological stress induced in transplants of the aquatic moss Fontinalis antipyretica Hedw.

We examined the effects of urban-derived fluvial contamination on aquatic bryophytes with the aim of improving use of these organisms for active biomonitoring of this type of contamination. Samples of the aquatic moss Fontinalis antipyretica were transplanted to five sites of a river affected by different levels of urban contamination. The aquatic contamination was characterized by a series of physical and chemical parameters, which were then related to the physiological responses determined in transplants of the bryophyte. Comparison of the data revealed the physiological parameters that best differentiated between levels of contamination. The active biomonitoring technique proved to be a clear and rapid method of determining the existence of a contamination gradient on the basis of the degree of pigmentary and photosynthetic stress in the moss transplants. Of the parameters considered, the concentration of phaeopigments and the net photosynthetic rate provided the clearest responses.