Biogeochemical modeling of the Marano and Grado lagoon (Italy) adding a benthic-pelagic coupling

The Marano and Grado Lagoon, situated in the northeastern coast of Italy, is a shallow coastal ecosystem of significant ecological value at both regional and international levels. The effects of human activities related to local socio-economic development, alongside climate variability, necessitate a deeper understanding of the lagoon's trophic dynamics and the development of effective management strategies. In this study, we present a multi-year analysis of the biogeochemistry of the Marano and Grado Lagoon, utilizing both observational data and a high-resolution coupled physical-biogeochemical model that incorporates explicit benthic-pelagic interactions. This model integrates the transport model SHYFEM (available at https://github.com/SHYFEM-model/shyfem) with the biogeochemical model BFM (Biogeochemical Flux Model, bfm-community.eu/). The biogeochemical component simulates processes in both the water column and sediments, also ensuring their coupling. We conducted ten-year simulations for the physical-chemical properties (2006-2015) and five-year simulations for the biogeochemical processes (2010-2014). Our findings reveal that the distributions of the pelagic biogeochemical state variables align reasonably well with the observed data, while the concentrations of benthic state variables are consistent with established characteristics of the lagoon benthic environment.