Bacterioplankton and bacterioperiphyton composition was analyzed using the CARD-FISH technique in three shallow lakes of the Pampean Plain (Argentina) with contrasting regimes: clear vegetated, turbid due to phytoplankton and turbid inorganic, due to inor

IZAGUIRRE I.; SÁNCHEZ, M.L.; SCHIAFFINO, M. R.; O' FARRELL, I.; HUBER, P.; FERRER, N.; ZUNINO, J.; LAGOMARSINO, L.; MANCINI, M.

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2015 vol. 752 p. 47 - 64

0018-8158

We investigated nine Pampean shallowlakes (Argentina) across a moisture gradient (meanannual precipitation 1,000?500 mm), under the frameworkof a network project of lakemonitoring whosemainobjective was to analyse the responses of ecosystems todifferent stressors associated with human activities. Wepostulate that species bloom in different shallow lakeswill be determined mainly by local optical features,nutrients and salinity. We analysed the phytoplanktonstructure during the warm season 2012?2013, identifyingthose species and functional groups that proliferate in thelakes. Most lakes showed high phytoplankton biomass,except a saline lake located in the driest part of thegradient and an inorganic turbid lake. In some lakes,cyanobacteria blooms occurred in summer, persistinguntil autumn. Small colonial cyanobacteria and smallfast-growing chlorophytes were abundant in most turbidenriched and anthropogenically impacted systems. Lowestspecies and functional diversity occurred in the salinelake.Multivariate analysis indicated that the phytoplanktonstructure was mainly defined by conductivity,transparency and variables associated with the trophicstate, also reflecting the importance of the geographicallocation. Our results evidenced the vulnerability of mostshallow lakes in the region to water level fluctuations,eutrophication and canalization.