Irina Izaguirre

Learn More
Shallow lakes often alternate between two possible states: one clear with submerged macrophytes, and another one turbid, dominated by phytoplankton. A third type of shallow lakes, the inorganic turbid, result from high contents of suspended inorganic material, and is characterized by low phytoplankton biomass and macrophytes absence. In our survey, the(More)
This study deals with the variation in the algal assemblages across the transversal dimension of a wetland of the Lower Paraná River from October 1998 to September 1999. The relationship between the algal composition and the physico-chemical variables is analyzed by means of Canonical Correspondence Analysis. The abundant floating macrophytes generated a(More)
The impact of the widely used herbicide glyphosate has been mainly studied in terrestrial weed control, laboratory bioassays, and field studies focusing on invertebrates, amphibians, and fishes. Despite the importance of phytoplankton and periphyton communities at the base of the aquatic food webs, fewer studies have investigated the effects of glyphosate(More)
The morpho-functional classifications of phytoplankton have been recently proposed as useful tools in the aquatic biomonitoring. In this study, we compared three different classifications in a range of different environmental conditions, a set of six shallow lakes with different stable states. The studied lakes are located in the Pampa Plain from Argentina,(More)
Nine lakes and ponds of Hope Bay (Antarctic Peninsula), with different trophic status were surveyed during four summer periods between 1991 and 1996. Some limnological features and the structure of their algal assemblages were strongly influenced by the eutrophication caused by sea-birds activity in their areas. Such differences among lakes were evidenced(More)
Two Antarctic lakes near Hope Bay were studied during summers 1998 and 1999. One of the lakes (Boeckella) is located near Esperanza Station and exhibits a meso-eutrophic condition due to the input of nutrients of a nearby penguin rookery. Its surface generally remains ice-free during the Antarctic summer (December–March). The other lake (Chico) is situated(More)
This study was conducted in a wetland on the Lower Paraná River (Argentina). Algal assemblages from a permanent shallow lake, three relict oxbow lakes (ROL) and an isolated small pond were sampled fortnightly during the spring-summer time of 1998–99. The algal assemblages strongly differed among the permanently vegetated ROLs and the shallow lake and small(More)
This 10-year field data study explores the relevance of water level fluctuations in driving the shift from a free-floating plant (FFP) to a phytoplankton dominated state in a shallow floodplain lake from the Lower Paraná River. The multi-year natural flood pulse pattern in the Lower Paraná River drove the ecosystem regime from a FFP-dominant state during(More)
The zooplankton biomass of Lake Boeckella (Hope Bay, Antarctic Peninsula) is strongly dominated by the calanoid copepod Boeckella poppei Mrázek. This work analyses the grazing impact of this copepod on the two dominant fractions of phytoplankton, pico- and nanoplankton, and on the bacterioplankton. By means of in-situ experiments using microcosms, the(More)
Phytoplankton in water samples from the lower delta of the Paraná river (Argentina) and in the gut contents of a local populaton of the Asiatic clam Corbicula fluminea was identified and counted monthly between April 1992 and March 1993. Relative abundances of algal species were generally similar in the medium and in the stomachs of clams, suggesting the(More)