No limit? : the multiphasic uptake of silicic acid by benthic diatoms - Université de Bretagne Occidentale Access content directly
Journal Articles Limnology and Oceanography Year : 2009

No limit? : the multiphasic uptake of silicic acid by benthic diatoms

Abstract

Silicic acid uptake kinetics for a field population of benthic diatoms were examined using a radioisotope tracer over a concentration range of 0-300 μmol L-1. The microphytobenthos half saturation constant (54 μmol L-1) and specific uptake rates (0.096 h-1) for silicic acid were well above those usually found in the pelagic environment. Silicic acid kinetics were hyperbolic only at low concentrations (< 60 μmol L-1). At higher concentrations, a second mechanism that did not suggest saturation was activated. Many benthic diatoms are motile and migrate vertically in the upper few centimeters of sediment where there are strong gradients of nutrient concentrations. The multiphasic uptake may allow them to take maximum advantage of the high silicic acid concentrations found at depth.

Domains

Oceanography
Fichier principal
Vignette du fichier
Leynaert_et_al_L_O_2009.pdf (1.22 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

hal-00451210 , version 1 (28-01-2010)

Identifiers

  • HAL Id : hal-00451210 , version 1

Cite

Aude Leynaert, Sorcha Ni Longphuirt, Pascal Claquin, Laurent Chauvaud, Olivier Ragueneau. No limit? : the multiphasic uptake of silicic acid by benthic diatoms. Limnology and Oceanography, 2009, 54 (2), pp.571-576. ⟨hal-00451210⟩
408 View
604 Download

Share

Gmail Facebook X LinkedIn More