INVESTIGADORES
IZAGUIRRE Irina
artículos
Título:
Algal communities of a geothermally heated lagoon from Deception Island (South Shetland Island)
Autor/es:
IZAGUIRRE, I.; ALLENDE, L.; TELL GUILLERMO
Revista:
POLAR BIOLOGY
Editorial:
Springer
Referencias:
Año: 2006 vol. 29 p. 364 - 371
ISSN:
0722-4060
Resumen:
Kroner Lake, located at Deception Island
(Maritime Antarctica), is a unique geothermally heated
lagoon in Antarctica. It is declared as special site of scientific interest (SSSI) by Scientific Committee for Antarctic Research (SCAR) for its high biodiversity. A sharp
environmental heterogeneity is registered in this lagoon,
due to its connection to the sea in its southern margin,
and to the input of warm freshwater in the northern one
(because of hot springs). This study analyses the biodiversity and abundance of the algal communities (phytoplankton and benthic assemblages) and their relationship
with environmental factors. In particular, strong spatial
differences of both temperature and conductivity were
recorded. The biological studies revealed that the phytoplankton (nanoplankton and microplankton) was
dominated by marine diatom species, while the pico-sized
fraction was composed by Cyanobacteria Synechococcus-like cells. The epipelon was mainly represented by
chain and tubicolous diatoms, among which, Melosira
nummuloides was one of the most abundant species.
Filamentous Cyanobacteria were also frequently recorded in the algal mats. Kroner Lake is subject to a
strong marine influence. Phytoplankton is absolutely
dominated by marine diatoms. Spatial variations in
temperature and conductivity recorded in the lagoon
influence the distribution of the aquatic communities.
The greater abundance of pico-sized cells coincided with
the warmest site of the water body. Regarding the benthic community, the contribution of freshwater and
brackish species is comparatively more important than
for the phytoplankton, although the high contribution of
marine-derived algae was also evident.