Microstructure of microphytobenthic biofilm and its spatio-temporal dynamics in an intertidal mudflat (Aiguillon Bay, France)

Microphytobenthos in Shallow Arctic Lakes: Fine-Scale Depth Distribution of Chlorophylla, Radiocarbon Assimilation, Irradiance, and Dissolved O2

“…Our fine-scale analysis of the vertical distribution of sediment chl a (Fig. 1) is in qualitative agreement with similar high resolution measurements from coastal marine environments that show a maximum chl a concentration in the surface 1 mm of sediment with continuously decreasing or reduced but constant chl a concentrations with increasing sediment depth below 1 mm to 5 or 10 mm (MacIntyre and Cullen, 1995;Herlory et al, 2004;Cartaxana et al, 2006). A chl a maximum in surficial marine sediment may be attributed to settling of suspended material from overlying water prior to core processing (MacIntyre and Cullen, 1995).…”

Does sediment grain size affect diatom grazing by harpacticoid copepods?

“…We estimated that an average of 125,000 diatom cells/copepod would correspond to food limitation, so there was suYcient food available in our experimental units. There were no data on diatom concentration in the Weld situation, however it is well known that diatom bioWlms are well-established on intertidal mudXats (e.g., Bellinger, Abdullahi, Gretz, & Underwood, 2005;Decho, 2000;Herlory, Guarini, Richard, & Blanchard, 2004) though these bioWlms are very variable depending on light conditions (pers. observ.…”

“…The EPS matrix of bioWlm forms sticky coatings on individual sediment particles and detrital surfaces, which act as a stabilizing anchor to buVer cells and their extracellular processes during frequent physical stresses (e.g., changes in salinity and temperature, UV irradiation, desiccation) (Decho, 2000). Especially intertidal mudXats, where the test harpacticoid species were collected from, are known for these extended bioWlms of microphytobenthos (e.g., Bellinger et al, 2005Decho, 2000Herlory et al, 2004).…”

Endogenous versus environmental control of vertical migration by intertidal benthic microalgae

“…This rhythmic behaviour has been considered a key adaptation to the sedimentary intertidal habitat (Seroˆdio & Catarino, 2000;Mitbavkar & Anil, 2004). Upward migration allows the microalgae to reach the illuminated layers of the sediment and photosynthesize, which is of crucial importance because of the periodic disturbance caused by tidal resuspension and subsequent burial in aphotic layers of the sediment (Herlory et al, 2004;ChulHwan et al, 2006;Mitbavkar & Anil, 2006). On the other hand, downward migration may help microalgae to avoid grazers (Buffan-Dubau & Carman, 2000), minimize resuspension into the water column (Kingston, 1999b), promote access to carbon or nutrients Kromkamp et al, 1998;Kingston, 1999bKingston, , 2002, or facilitate sexual reproduction (Saburova & Polikarpov, 2003).…”