Numerical analysis of the food web of an intertidal mudflat ecosystem on the Atlantic coast of France
Leguerrier, D.; Niquil, N.; Boileau, N.; Rzeznik-Orignac, J.; Sauriau, P.G.; Le Moine, O.; Bacher, C. (2003). Numerical analysis of the food web of an intertidal mudflat ecosystem on the Atlantic coast of France. Mar. Ecol. Prog. Ser. 246: 17-37
Food web modelling is an ideal way to describe ecosystems, because it accounts for thetotality of the relationships between its various components. One difficulty of such an approach, however,lies in the lack of data and information about some ecological relationships, resulting in underdefinedsystems. Inverse analysis can serve to complete steady-state food webs where the number ofdirect flow measurements is insufficient relative to the actual number of flows. We applied thismethod to the intertidal mudflat ecosystem of Brouage (eastern Marennes-Oléron Bay, SW France)and estimated the annual average carbon flows between the compartments of a coupled benthic andpelagic trophic food web from primary producers (microphytobenthos and phytoplankton) to toppredators (fish and birds). The resulting network was very sensitive to the primary production of themicrophytobenthos which was the most important flow in the system. Sensitivity analyses demonstratedthe need for additional data on the nekton, pelagic protozoa, and bacterial compartments. Theresulting network showed high bacterial activity, but indices resulting from network analysis showedlow cycling in comparison with other ecosystems. The meiofauna had a small biomass, but constituteda very active compartment compared to the macrofauna. Bird production was limited by macrofaunalproduction. Macrofaunal production reached the maximum allowed by the analysis. The intertidalmudflat ecosystem at Brouage is dominated by benthic production (including benthic primaryproducers, secondary producers, and predators) with an input of phytoplankton primary production.
