Blanchard, G. F.. University of La Rochelle, gblancha@ifremer.fr
Guarini, J. F.. Centre de Recherche en Ecologie marine et Aquaculture de L'Houmeau,
Gros, P. Centre de Brest, phgros@ifremer.fr

 
A THEORETICAL SCHEME OF MICROALGAL PRIMARY PRODUCTIVITY: THE CASE OF MARINE INTERTIDAL MUDFLATS
 
We propose a theoretical scheme of microphytobenthos productivity, which is specific to marine intertidal mudflats. This model is based on the most relevant processes which allow to work out a consistent conceptual framework. Spatially, microalgae can move vertically from complete darkness to full sunlight over a few hundreds microns and within a few minutes because of their active behavior towards light. Temporally, the succession of photic exondation periods and aphotic submersion periods - because of the high turbidity of the water - on the intertidal mudflats, combined together with the nycthemeral cycle, gives rise to predictible movements of microalgae towards and away from the photic zone, respectively. From a behavioral standpoint, finally, microalgae appear to switch around continuously from an aphotic sub-system to a photic sub-system - in both ways due to a reversal of the phototaxy, each status being well defined by its own set of processes. Thus, such characteristics basically define a new type of marine productivity system for which there has not been yet a theoretical overview which is nevertheless necessary to appraise its role in the functioning of littoral ecosystems. We present both the conceptual scheme and the frame of the mathematical model.
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: SS46TH1693S