INVESTIGADORES
FERREYRA Gustavo Adolfo
artículos
Título:
The genus Pseudo-nitzschia (Bacillariophyceae) in continental shelf waters of Argentina (Southwestern Atlantic Ocean, 38-55°S)
Autor/es:
ALMANDOZ, G., M.E. FERRARIO, G.A. FERREYRA, I.R. SCHLOSS, J.L. ESTEVES AND F. PAPARAZZO
Revista:
Harmful Algae
Editorial:
Elsevier
Referencias:
Año: 2007 vol. 6 p. 93 - 103
Resumen:
The distribution pattern of Pseudo-nitzschia species, associated phytoplankton flora and its relationships with main environmental
factors were studied for the first time in continental shelf surface waters of the Argentine Sea (Southwestern Atlantic Ocean,
38
558S). Both qualitative and quantitative samples, collected during summer and fall 2003, were examined using light and
scanning electron microscopy. Results indicated that the genus Pseudo-nitzschia has a wide distribution along the studied area. It
was present at low densities, with infrequent peak abundances and appeared most frequently as a minor component of the diatom
populations that typically develop on the continental shelf of the Argentine Sea. Moreover, phytoplankton communities were
numerically dominated by unidentified phytoflagellates (5 mm) throughout almost all samples analyzed. Eight Pseudo-nitzschia
species were identified in our study: P. australis, P. fraudulenta, P. heimii, P. lineola, P. pungens, P. cf. subcurvata, P. turgidula and
P. turgiduloides. Of these, P. heimii, P. lineola and P. turgiduloides are new records for the Argentine Sea. Their presence in the area
is attributable to the influence of southerly cold water masses. Spatial and temporal variations of the environmental parameters
recorded in the study area generally determined the distribution of Pseudo-nitzschia species. P. pungens and P. australis were widely
distributed and reached high densities, especially in waters with elevated temperatures and salinities (around 15 8C, 33.8 psu) and
low nutrients concentrations. On the other hand, P. heimii, P. lineola, P. turgidula and P. turgiduloides showed a more restricted
distribution, with lower densities in relatively cold, less saline (8 8C, 32.45 psu) and nutrient-rich waters. From the Pseudo-nitzschia
species found throughout this survey, P. australis, P. fraudulenta, P. pungens and P. turgidula are known as domoic acid (DA)
producers around the world, but there is little information on the potential toxicity of these species in Argentina.
# 2006 Elsevier B.V. All rights reserved.