Title of article :
Phosphorus diagenesis in sediment of the Thau Lagoon
Author/Authors :
Pierre Anschutz، نويسنده , , Gwénaëlle Chaillou، نويسنده , , Pascal Lecroart، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
Abstract :
We describe the depth distribution of phosphorus in relation to the distribution of major redox species (dissolved O2, NO3
, NH4
þ, Mn, and Fe,
and particulate S, organic C, reactive Mn- and Fe-oxides) in modern sediments of two stations in the Thau Lagoon. Sediments close to the oyster
bank zone are enriched in organic carbon and are highly bioturbated, while those outside the bank are less bioturbated and organic carbon levels
are lower. In all sites, early diagenesis follows the well-accepted depth sequence of redox reactions of organic matter mineralization. The upper
sediments of the station enriched in organic carbon contain high amounts of reactive particulate organic phosphorus that arrives at the sediment
surface through biodeposition. Only a part of this phosphorus is released to the bottom water after mineralization, since more than 50% of total P
is buried as an authigenic phosphate mineral. In the middle of the lagoon, outside the oyster bank zone, organic matter seems to be much more
refractory, but the distribution of the major redox compounds indicates that this organic matter is partially mineralized. A portion of the phosphate
and ammonium released during mineralization does not escape the sediment, since the concentration gradient is close to zero between 1
and 25 cm depth below the sedimentewater interface. Pore water N and P are likely fixed by biological uptake. The characterisation and
magnitude of this process require further study.
Keywords :
Phosphorus , sediment , Early diagenesis , Thau lagoon
Journal title :
Estuarine, Coastal and Shelf Science
Journal title :
Estuarine, Coastal and Shelf Science