Spatial and temporal interaction between sediment and microphytobenthos in a temperate estuarine macro-intertidal bay
|Author(s)||Orvain Francis1, 2, Lefebvre Sebastien1, 3, Montepini J.1, Sebire M.1, Gangnery Aline4, Sylvand B.5, 6|
|Affiliation(s)||1 : Univ Caen Basse Normandie, BIOMEA CNRS FRE3484, F-14032 Caen, France.
2 : CNRS, Museum Nat Hist, CRESCO, UMR BOREA 7208, F-35800 Dinard, France.
3 : Univ Lille1, Sci & Technol, CNRS, Lab Oceanol & Geosci, Stn Marine Wimereux,UMR 8187, F-62930 Wimereux, France.
4 : IFREMER, Lab Ressources Halieut, Stn Port En Bessin, F-14520 Port En Bessin, France.
5 : GEMEL Normandie, Stn Marine Luc Sur Mer, F-14530 Luc Sur Mer, France.
6 : Univ Caen, F-14032 Caen, France.
|Source||Marine Ecology-progress Series (0171-8630) (Inter-research), 2012 , Vol. 458 , P. 53-68|
|WOS© Times Cited||30|
|Keyword(s)||Benthic diatoms, Benthos, Coastal ecosystems, Intertidal flats, Baie des Veys, Normandie, Spatial pattern, Geostatistics, Kriging|
|Abstract||Intertidal flats of the estuarine macro-intertidal Baie des Veys (France) were investigated to identify spatial features of sediment and microphytobenthos (MPB) in April 2003. Gradients occurred within the domain, and patches were identified close to vegetated areas or within the oyster-farming areas where calm physical conditions and biodeposition altered the sediment and MPB landscapes. Spatial patterns of chl a content were explained primarily by the influence of sediment features, while bed elevation and compaction brought only minor insights into MPB distribution regulation. The smaller size of MPB patches compared to silt patches revealed the interplay between physical structure defining the sediment landscape, the biotic patches that they contain, and that median grain-size is the most important parameter in explaining the spatial pattern of MPB. Small-scale temporal dynamics of sediment chl a content and grain-size distribution were surveyed in parallel during 2 periods of 14 d to detect tidal and seasonal variations. Our results showed a weak relationship between mud fraction and MPB biomass in March, and this relationship fully disappeared in July. Tidal exposure was the most important parameter in explaining the summer temporal dynamics of MPB. This study reveals the general importance of bed elevation and tidal exposure in muddy habitats and that silt content was a prime governing physical factor in winter. Biostabilisation processes seemed to behave only as secondary factors that could only amplify the initial silt accumulation in summer rather than primary factors explaining spatial or long-term trends of sediment changes.|