INVESTIGADORES
GOMEZ Nora
artículos
Título:
Phytoplankon of small lowland stream related to water quality and hydraulic discontinuities
Autor/es:
BAUER, D. E.; CONDE, M. E.; GOMEZ, N.
Revista:
ARCHIV FUR HYDROBIOLOGIE
Editorial:
E. Schweizerbart' sche Verlagsbuchhandlung
Referencias:
Lugar: Alemania; Año: 2002 vol. 153 p. 421 - 442
ISSN:
0003-9136
Resumen:
Abstract: The structure and dynamics of the
phytoplankton related to water quality and hydraulic characteristics
were studied in a 12 km reach of the
Rodríguez Stream, a tributary of the Río de la Plata, in Argentina. This stream
includes a small artificial pond.
Samples were taken seasonally along a year at three sites at the stream and
once at
the pond. Water quality according to
physical and chemical parameters was better at site 1 than at downstream sites.
Changes in phytoplankton assemblages
descriptors were observed with increasing nutrients and water residence
time. The spatial water quality
changes are coincident with the hydraulic discontinuity. This situation
suggests a
synergic effect among the
phytoplanktonic descriptors that were analyzed. There was a high percentage of
species
belonging to euglenoids followed by
green algae and diatoms. Loricated euglenoids were dominant at site 1,
clorococcalean greens dominated at
the pond and decreased progressively downstream, at sites 2 and 3.
Gomphonema
parvulum, Nitzchia palea and N. umbonata were abundant in the latter sites, where current
velocity
increased. Our results also show the
integrating character of the phytoplankton in this small stream where it can
reach considerable development due
to the low gradient (<10-3), and specially to the presence of the
pond.