title: PRESENCE OF ALGAE IN FRESHWATER ICE COVER OF FLUVIAL LAC SAINT-PIERRE (ST. LAWRENCE RIVER, CANADA)(1).
abstract: Winter ice cover is a fundamental feature of north temperate aquatic systems and is associated with the least productive months of the year. Here we describe a previously unknown freshwater habitat for algal and microbial communities in the ice cover of the freshwater St. Lawrence River, Quebec, Canada. Sampling performed during winter 2005 revealed the presence of viable algal cells, such as Aulacoseira islandica (O. Müll.) Simonsen (Bacillariophyceae), and microbial assemblage growing in the ice and at the ice-water interface. Vertical channels (1-5 mm wide) containing algae were also observed. Concentrations of chl a ranged between 0.5 and 169 μg · L(-1) of melted ice, with maximal concentrations found in the lower part of the ice cores. These algae have the potential to survive when ice breakup occurs and reproduce rapidly in spring/summer conditions. Freshwater ice algae can thus contribute to in situ primary production, biodiversity, and annual carbon budget in various habitats of riverine communities.
authors.affiliation: Département de Chimie-Biologie, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, Québec G9A 5H7, CanadaPhycology Section, Research Division, Canadian Museum of Nature, PO Box 3443, Station D, Ottawa K1P 6P4, Canada.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Frenette
authors.affiliation: Département de Chimie-Biologie, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, Québec G9A 5H7, CanadaPhycology Section, Research Division, Canadian Museum of Nature, PO Box 3443, Station D, Ottawa K1P 6P4, Canada.
authors.forename: Patrice
authors.initials: P
authors.lastname: Thibeault
authors.affiliation: Département de Chimie-Biologie, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, Québec G9A 5H7, CanadaPhycology Section, Research Division, Canadian Museum of Nature, PO Box 3443, Station D, Ottawa K1P 6P4, Canada.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Lapierre
authors.affiliation: Département de Chimie-Biologie, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, Québec G9A 5H7, CanadaPhycology Section, Research Division, Canadian Museum of Nature, PO Box 3443, Station D, Ottawa K1P 6P4, Canada.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Hamilton
keywords: Bacillariophyceae; Chlorophyta; fluvial lake; freshwater; ice algae; protist; spatial distribution; sympagic communities; temperate ecosystem; vertical channels