IMIS | Flanders Marine Institute
 

Flanders Marine Institute

Platform for marine research

IMIS

Publications | Institutes | Persons | Datasets | Projects | Maps
[ report an error in this record ]basket (0): add | show Printer-friendly version

Export fluxes of organic carbon and lipid biomarkers from the frontal structure of the Alboran Sea (SW Mediterranean Sea) in winter
Tolosa, I.; LeBlond, N.; Marty, J.-C.; de Mora, S.; Prieur, L. (2005). Export fluxes of organic carbon and lipid biomarkers from the frontal structure of the Alboran Sea (SW Mediterranean Sea) in winter. J. Sea Res. 54(2): 125-142. dx.doi.org/10.1016/j.seares.2005.04.002
In: Journal of Sea Research. Elsevier/Netherlands Institute for Sea Research: Amsterdam; Den Burg. ISSN 1385-1101, more
Peer reviewed article  

Available in  Authors 

Keywords
    Biomarkers; Chlorophylls; Fatty acids; Particulate flux; Particulate organic matter; Sterols; Mediterranean [Marine Regions]; MED, Alboran Sea [Marine Regions]; Marine

Authors  Top 
  • Tolosa, I.
  • LeBlond, N.
  • Marty, J.-C.
  • de Mora, S.
  • Prieur, L.

Abstract
    The concentrations and fluxes of total mass, particulate organic carbon (POC), chlorophyll-a equivalent and lipid biomarker classes were measured in large sinking particulate matter collected in winter 1997/98 at two water depths (100 and 300 m) in the Almeria-Oran frontal zone (SW Mediterranean). Three water masses, comprising the Frontal Atlantic jet, the anticyclonic Atlantic gyre and the surrounding Mediterranean waters, were investigated over two days, using free-drifting sediment traps that collected at intervals of 7-9 h to evaluate night-day variations. Fluxes of mass, POC, chlorophyll-a and lipids out of the euphotic zone varied spatially, ranging from 136 to 1430 mg m-2 d-1 for mass, 21 to 105 mg m-2 d-1 for POC, 0.1 to 1 mg m-2 d-1 for equivalents of chlorophyll-a, and 1.2 to 6 mg m-2 d-1 for lipids, with the highest export rates measured in the Atlantic gyre downstream and the lowest in the jet core. All fluxes showed a decrease with increasing water column depth, but the flux difference between the sediment traps at 100 and 300 m depths was most pronounced in the gyre downstream, where the higher fluxes in the shallow trap were a consequence of the accumulation of relatively fresh phytoplanktonic material from the frontal zone. At the Mediterranean site, the relatively low mass fluxes coincided with relatively high organic carbon and lipid concentrations. Lipids comprised 20% of POC in particles leaving the euphotic zone of the Mediterranean site and only 6 to 10% in the frontal zone. In contrast, POC in particles transiting through the mesopelagic zone (at 300 m depth) comprised 6% of lipids at the Mediterranean site and up to 19% in the jet core of the Atlantic-modified water mass. These results demonstrate a strong decoupling between the shallow and deep traps in the frontal zone, denoting the presence of a transfrontal secondary circulation. In contrast, an important vertical export of the particulate organic matter with no influence of lateral advections was clearly observed in the Mediterranean waters. No substantial variation in flux and lipid composition of large particles was observed between day and night-time collection in the frontal and Mediterranean areas, indicating that the export flux resulted mainly from passive sedimentation of phytoplanktonic material.

All data in IMIS is subject to the VLIZ privacy policy Top | Authors