Seasonal modulation of microbially mediated carbon fluxes in the northern Adriatic Sea — a model study

A model study of the seasonal changes in the food web structure of the northern Adriatic Sea is presented. A 1–D ecosystem coupled model (POM/ERSEM) forced with climatological functions has been applied at two different station locations in the northern Adriatic Sea, one under the direct influence of the Po river inflow and one representing a more open sea situation. The ability of the model to reproduce the main physical and biogeochemical patterns allows us to study the underlying carbon fluxes, which determine these features. Analysis of the seasonal carbon-transfer pathways among the main trophic levels shows a possible seasonal modulation at both stations, but a different food web development. It seems that the prevailing path could be related to the seasonal variability of the water column (nutrient input and/or vertical stratification). Moreover, results from this numerical experiment suggest that the northern Adriatic shallow coastal area has a predominantly multivorous food web and has significant microbial recycling, even if this latter pattern is not so evident as in open sea areas.