Publications des scientifiques de l'IRD

Rodier Martine, Le Borgne Robert. (2008). Population dynamics and environmental conditions affecting Trichodesmium spp. (filamentous cyanobacteria) blooms in the south-west lagoon of New Caledonia. Journal of Experimental Marine Biology and Ecology, 358 (1), p. 20-32. ISSN 0022-0981.

Titre du document
Population dynamics and environmental conditions affecting Trichodesmium spp. (filamentous cyanobacteria) blooms in the south-west lagoon of New Caledonia
Année de publication
2008
Type de document
Article référencé dans le Web of Science WOS:000255448300003
Auteurs
Rodier Martine, Le Borgne Robert
Source
Journal of Experimental Marine Biology and Ecology, 2008, 358 (1), p. 20-32 ISSN 0022-0981
The present description of Trichodesmium spp. population dynamics and associated environmental variables is the first one using a very short sampling interval (2-3 days). Such a strategy allows a fine description of changes involving the population density and characteristics. It also tends itself to interpreting those changes from past environmental conditions. During the two surveys, 2 and 5 month-long, T. erythraeum dominated the Trichodesmium population, with temporary occurrence of T. thiebautii and five blooms could be described. These events appeared at temperatures >24 degrees C and followed, in all cases, nitrate, soluble reactive phosphorus and chlorophyll a enrichments, with a 3-7 day time lag. Low wind speed (<4 m s(-1)) was not a prerequisite for Trichodesmium bloom developments as long as temperatures exceeded 26 degrees C. As abundance increased during the bloom, so did the number of filaments (trichomes) in colonies and their buoyancy, leading to a clear positive biomass gradient from the bottom to the surface. A simple model, using variable growth rates, showed trichome ascent would be responsible for 87-99% of concentrations at 0.5 m, with Trichodesmium net growth rates ranging from 0.11 to 0.38 d(-1). Finally, rapid trichome density declines could be ascribed to nutrient depletion and massive surface death following ascent.
Plan de classement
Limnologie biologique / Océanographie biologique [034]
Identifiant IRD
fdi:010042557
Contact
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