Picophytoplankton during the ice-free season in five temperate-zone rivers

Contant, J; Pick, FR

HERO ID

3608353

Reference Type

Journal Article

Year

2013

Language

English

PMID

23641118

HERO ID 3608353
In Press No
Year 2013
Title Picophytoplankton during the ice-free season in five temperate-zone rivers
Authors Contant, J; Pick, FR
Journal Journal of Plankton Research
Volume 35
Issue 3
Page Numbers 553-565
Abstract Although picophytoplankton (PP) (0.2-2 μm) are ubiquitous in lakes and oceans, their importance in rivers has rarely been studied. We examined PP assemblages during the ice-free period in five rivers of a temperate region varying in trophic state (9-107 μg/L total phosphorus) and water discharge (1-87 m3/s). In these rivers, PP abundance reached concentrations as high as those observed in lakes and oceans (∼104-105 cells/mL). The highest density of PP (4.9 × 105 cells/mL) was observed in the most eutrophic river when the water temperature (28°C) and total phosphorus (293 μg/L) were highest. For the most part, PP abundance was dominated by non-phycoerythrin-containing cyanobacteria; phycocyanin-rich cells accounted for ∼75% of PP abundance in all the rivers. In multiple regression analyses, water temperature and nitrate concentrations explained about half of the variation in PP abundance across the rivers. Discharge had no effect on PP abundance or biomass, whereas it had a significant negative effect on total algal biomass among the rivers. The PP contribution to total chlorophyll-a averaged 27% (ranging 16-46%) and did not decline with increasing nutrients as found in lakes and oceans. The PP biomass from microscopic enumerations reached a maximum of 9% of total phytoplankton biomass, comparable with that observed in lakes. The results of this study demonstrate the importance of including picophytoplankton when analysing phytoplankton communities in rivers. © 2013 The Author.
Doi 10.1093/plankt/fbt013
Pmid 23641118
Wosid WOS:000318573100008
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English