Both lake regime and fish introduction shape autotrophic planktonic communities of lakes from the Patagonian Plateau (Argentina)

FRANCISCO, SAAD JUAN; SOL, PORCEL; JULIO, LANCELOTTI; INÉS, O'FARRELL; IRINA, IZAGUIRRE

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2018

0018-8158

Abstract Strobel Plateau hosts more than 1,500shallow lakes displaying different water regimes,which constitute the habitat for many species.Although the region is naturally fishless, many of thelakes were stocked with trout, bearing uncertaintyabout the possible effects on the ecosystem. The mainobjective of this study was to analyze the character-istics of planktonic autotrophic communities of lakesdiffering in regime (phytoplankton turbid, clear veg-etated, and clear unvegetated) and presence/absence offish. During late spring and summer, 14 water bodies were sampled in 2011 and 2013 considering differentregimes and presence/absence of fish. Besides limno-logical variables, the autotrophic communities, frompico to microplankton, were also analyzed. Differ-ences in physical and chemical characteristicsobserved among the lakes corresponded to theircurrent regime and the presence/absence of trouts.Autotrophic picoplankton and phytoplank-ton [ 20 lm abundances differed among lake typesbeing highest in fish-stocked lakes. Although the threetype of lakes presented phycoerythrin-rich pico-cyanobacteria and picoeukaryotes, only fish-stockedlakes hosted phycocyanin-rich picocyanobacteria.Moreover, fish-stocked lakes were dominated bycyanobacteria, while chlorophytes abounded in fish-less systems. Evidences that lake regime and fishoccurrence influence planktonic autotrophic commu-nities of Strobel plateau is here provided, highlightingthe intra- and interannual dynamism of the aquaticsystems.