SS4.08 Global Freshwater Quality: Issues, needs and solutions
Date: Wednesday, June 12, 2002
Time: 11:45:00 AM
Location: Carson A
 
SabaterS, Univ. Girona, Girona, Spain, sergi.sabater@udg.es
Vilalta, E, , Univ. Barcelona, Barcelona, Spain, vilalta@porthos.bio.ub.es
Guasch, H, , Univ. Girona, Girona, Spain, hguasch@porthos.bio.ub.es
Muņoz, I, , Univ. Barcelona, Barcelona, Spain, munoz@porthos.bio.ub.es
Romani, A, , Univ. Girona, Girona, Spain, anna.romani@udg.es
Valero, F, , ATLL, Barcelona, Spain, fvalero@atll.es
Rodriguez, J, J, ATLL, Barcelona, Spain, jjrodriguez@atll.es
 
ENVIRONMENTAL AND BIOLOGICAL FACTORS RELATED WITH MASSIVE GROWTH OF BENTHIC CYANOBACTERIA PRODUCING NUISANCE ODOURS
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Water use in river systems may be affected by the occurrence of nuisance odours. A common cause for them is the metabolite geosmin, which produce earthy and musty odours at low thresholds. We examine the case of two large rivers affected by water withdrawal and high nutrient inputs from human activities. While in one of them (Ter River) odours have not been reported, in the other (Llobregat River) repeated episodes of geosmin consistently occurred from early winter to late spring. Geosmin episodes in the Llobregat coincided with the development of thick cyanobacterial mats in pools and littoral areas. Several taxa of Oscillatoria were dominant in the mats. Analyses of geosmin in the mat confirmed that these taxa were geosmin-producers. Later in time, the mats collapsed and the odour disappeared from the river. The structural and physiological evolution of the cyanobacterial mats through time, as well as the changes in the environmental variables in the two rivers, are analysed to determine the intimate causes related with the wax and wane of these mats and their corresponding odour production.