title: Spatio-temporal variations in biomass and mercury concentrations of epiphytic biofilms and their host in a large river wetland (Lake St. Pierre, Qc, Canada).
abstract: Within wetlands, epiphytes and macrophytes play an important role in storage and transfer of metals, through the food web. However, there is a lack of information about spatial and temporal changes in their metal levels, including those of mercury (Hg), a key priority contaminant of aquatic systems. We assessed total mercury (THg) and methylmercury (MeHg) concentrations of epiphyte/macrophyte complexes in Lake St. Pierre, a large fluvial lake of the St. Lawrence River (Québec, Canada). THg and MeHg concentrations were ten fold higher in epiphytes than in macrophytes. THg concentrations in epiphytes linearly decreased as a function of the autotrophic index, suggesting a role of algae in epiphyte Hg accumulation, and % of MeHg in epiphytes reached values as high as 74%. Spatio-temporal variability in THg and MeHg concentrations in epiphytes and macrophytes were influenced by water temperature, available light, host species, water level, dissolved organic carbon and dissolved oxygen.
authors.affiliation: GRIL, Département de sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre Ville, Montreal, Quebec H3C 3P8, Canada.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Hamelin
authors.affiliation: GRIL, Département de sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre Ville, Montreal, Quebec H3C 3P8, Canada.
authors.forename: Dolors
authors.initials: D
authors.lastname: Planas
authors.affiliation: GRIL, Département de sciences biologiques, Université de Montréal, C.P. 6128, Succursale Centre Ville, Montréal, Quebec H3C 3J7, Canada. Electronic address: m.amyot@umontreal.ca.
authors.forename: Marc
authors.initials: M
authors.lastname: Amyot
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D018533:Biomass; D004784:Environmental Monitoring; D020387:Food Chain; D060106:Lakes; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds / Q000032:analysis; D011792:Quebec; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Epiphytes; Macrophytes; Mercury; Methylmercury; Periphyton