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Please use this identifier to cite or link to this item: http://hdl.handle.net/1834/1464

Title: Estudios ecológicos en el Golfo San Jorge y adyacencias (Atlántico sudoccidental). Distribución, abundancia y variación estacional del fitoplancton en relación a factores físico-químicos y la dinámica hidrológica.
Other Titles: Ecological studies in San Jorge Gulf and adjacent areas (SW Atlantic). Phytoplankton distribution, abundance and seasonal variation in relation to physico-chemical factors and hydrology.
Authors: Akselman, R.
Theses advisor: Carreto, J.I.
ASFA Terms: Phytoplankton
Abundance
Trophic relationships
Cysts
Seasonal variations
Seasonal thermocline
Plankton surveys
Environmental effects
Issue Date: 1996
Abstract: This study was based on four seasonal cruises during 1984 and 1985. It revealed a thermo-haline frontal system formed by the advection of the Coastal Water mass flowing in two branches, one running towards the coast and the other mid-shelf directed. The thermocline developed between late spring and autumn results in a low inorganic nutrient concentration in the upper layer. Nonetheless in winter, a vertical homogeneity and high nutrient concentration were observed. Phytoplankton development presented a typical temperate-seas annual cycle. In winter, reduced populations were dominated by diatoms. The highest biomass concentration in the cycle coincided with the spring blooming, to which Thalassio sira anguste-lineata,Alexandrium tamarense, Heterocapsa triquetra and Prorocentrum micans were associated. Summer concentration decreased sharply with dinoflagellates being dominant, and a minor increase followed in autumn owing to diatom populations. Usually diatom growth was linked to the frontal region. The quali-quantitative flora composition denote this gulf as a southern transitional area with a dominance of temperate-cold communities. A high dinoflagellate cysts richeness and encystment were detected in spring. Trophic relations in the microplankton community were identified, and a spatial coupling of predator-dinoflagellates and photosynthetic prey-dinoflagellates was noted. Consumption and grazing and prey selectivity indexes were also estimated.
URI: http://hdl.handle.net/1834/1464
Appears in Collections:Tesis En Ciencias Marinas

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