METAL ACCUMULATION AND PIGMENT STRESS OF AQUATIC BRYOPHYTES FROM THE RIVER EUME, GALICIA (NW SPAIN)

A study is made of metal accumulation (Cu, Cd, Zn, Pb, Ni, Mn and Fe) and pigment stress caused in the following bryophytes: Fonrinalis antipyretica Hedw., Rhynchostegium riparioides (Hedw.) Card., Fissidens polyphyllrcs Wils. and Scapania undulata (L.) Dum., collected from the river Eume, Galicia (NW Spain). This river bears a gross metal pollution due to an open cast mine of a termal power station set up on its basin. S. undulata and F. polyphyllus were the species with the maximum and minimum accumulative efflciency respectively. Ni showed an exceptional mean value, higher than any published value. Correlations between metal concentrations in water-bryophytes were very low being significant only for Zn and Mn. The damaging effects of heavy metals on bryophytes can be observed in the high correlations found between pigment stress (ratio D665lD665a) and metal concentration. The evaluation of water quality by means of the calculation of contamination factors is also discussed