Reference : A descriptive study of physico-chemical characteristics of Posidonia oceanica litter acc...
Scientific congresses and symposiums : Poster
Life sciences : Aquatic sciences & oceanology
Life sciences : Environmental sciences & ecology
http://hdl.handle.net/2268/131577
A descriptive study of physico-chemical characteristics of Posidonia oceanica litter accumulation
English
Lepoint, Gilles mailto [Université de Liège - ULg > Département de Biologie, Ecologie et Evolution > Océanologie >]
Borges, Alberto mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique >]
Darchambeau, François mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique >]
Dauby, Patrick mailto [Université de Liège - ULg > Département de Biologie, Ecologie et Evolution > Systématique et diversité animale >]
Mascart, Thibaud mailto [Université de Liège - ULg > Département de Biologie, Ecologie et Evolution > Océanologie >]
Remy, François mailto [Université de Liège - ULg > Département de Biologie, Ecologie et Evolution > Océanologie >]
Champenois, Willy mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique >]
2012
No
No
International
10th International Seagrass Biology Workshop (25-30 November, Rio de Janeiro, Brazil)
from 25-11-12 to 30-11-12
World Seagrass Association
Buzos (Rio de Janeiro)
Brazil
[en] Macrophytodetritus ; seagrass ; hypoxy ; carbon cycle
[en] The Mediterranean seagrass Posidonia oceanica meadow losses every fall the major part of its leaf biomass after senescing. These phytodetritus may decay within the meadow, be buried or be exported to other habitats. They form large litter accumulations, notably on shallow water sand patches. Such accumulation host many organisms which participate to the degradation of this material. In a first step to understand the dynamics of these accumulations and of their associated biota, we have characterised their physico-chemical heterogeneity at different seasons. We measured the dissolved oxygen, nutrients and sulphide concentrations in interstitial waters from litter accumulations varying regarding their phytodetritus composition, fragmentation level and thickness. Results show that oxygen conditions were highly variable depending on litter thickness but also on local hydrodynamics. Anoxic conditions and presence of sulphide were sometimes measured, particularly in very thick litter or in degraded litter at the end of summer. Colonies of sulphur-oxidising bacteria were observed. Litter accumulations were also often enriched in ammonium and, sometimes, in dissolved phosphorus. It is not clear whether this results from the litter degradation within the accumulation or whether this is a consequence of a barrier effect between sediment and water column. Nevertheless, this makes litter accumulations particularly attractive for micro-phytobenthic producers. Litter accumulations appear as key habitats both to understand the dead-face of seagrass dynamics and its consequence for C cycle in coastal areas and to study the consequence of hypoxia on biodiversity in a natural context.
Centre Interfacultaire de Recherches en Océanologie - MARE
Fonds de la Recherche Scientifique (Communauté française de Belgique) - F.R.S.-FNRS
FRFC Dynamics of Posidonia litter accumulation
Researchers
http://hdl.handle.net/2268/131577

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Open access
Poster LEPOINT ET AL Litter ISBW10.pdfPublisher postprint3.06 MBView/Open

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.