IR Home
AME
Home
Editors
Forthcoming
Information
Subscribe
Journals
Home
MEPS
AME
CR
DAO
ESEP
Search
Subscribe
Book Series
EE Books
Top Books
Order
Discussion Forums
Home
Research
Endangered Species Programs
Institutions
International Ecology Institute
Eco-Ethics International Union
Foundation
Otto Kinne Foundation
| |
AME 17:267-278 (1999)
|
Abstract
|
![](../../../../images/hline.gif)
Nitrification rates in the NW Mediterranean Sea
Micheline Bianchi1,*, Christine Fosset1, Pascal Conan2
1Laboratoire de Microbiologie Marine, CNRS/INSU UPR 223, Université de la Méditerranée, Campus de Luminy, Case 907, F-13288 Marseille Cedex 9, France
2COM-LOB, Campus de Luminy, Case 901, F-13288 Marseille Cedex 9, France
*E-mail: m-bianchi@luminy.univ-mrs.fr
![](../../../../images/hline.gif)
ABSTRACT: During spring, ammonium oxidation and nitrite oxidation rates were measured in the NW basin of the Mediterranean Sea, from mesotrophic sites (Ligurian Sea and Gulf of Lions) to oligotrophic sites (Balearic Islands). Nitrification rates (average
values for 37 measurements) ranged from 72 to 144 nmol of N oxidised l-1 d-1, except in the Rhône River plume area where the rates increased to 264-504 nmol l-1 d-1 because of the riverine inputs of nitrogen.
Maximal rates were located around the peak of nitrite within the nitracline at about 40 to 60 m and just above the phosphacline. At 1 station, relatively high values of nitrification (50 to 130 nmol l-1 d-1) were also measured deep
in the water column (240 m). Day-to-day variations were measured demonstrating the response within a few hours to hydrological stress (wind-induced mixing of the water column) and showing the role of hydrological characteristics on the distribution of
nitrification rates. Because of the homogenous temperature (13°C) in the Mediterranean Sea, the spatial (geographical and vertical) fluctuations of nitrifying rates were linked to the presence of substrate due to mineralisation processes and/or Rhône
River inputs. We estimate the contribution of nitrate produced by nitrification to the N demand of phytoplankton to range from 16% at mesotrophic to 61% at oligotrophic stations.
KEY WORDS: Mediterranean Sea · Nitrification · Spatial variability · Short-term fluctuation · N budget
![](../../../../images/hline.gif)
Published in AME Vol.
17, No. 3
(1999) on June 18
ISSN: 0948-3055.
Copyright © Inter-Research, Oldendorf/Luhe, 1999
|