Bio-irrigation in simple diagenetic models: A study in the northwestern Adriatic

In the process of setting up a benthic-pelagic coupled model for the
northern adriatic Sea, the OMEXDIA model has been used to analyze
through model calibration, pore-water profiles and in-situ flux data in
that area. Both enhanced biodiffusive and non-local exchange formalisms
were tested to represent the impact on bioirrigation on pore water solute
profiles and benthic fluxes. Bayesian calibration procedure revealed that
only the non-local exchange formalism allows to render simultaneously
the pore water solutes profiles and fluxes at the sediment water interface
when inorganic carbon, oxygen, nitrate, ammonium and phosphate dy-
namics are considered jointly. While the enhanced-biodiffusive formalism
is convenient to compare diffusive and total benthic fluxes of a single vari-
able (derived from solutes profiles and incubation chambers respectively),
it is not suited for multivariate modelling purposes. We evidence that the
impact of bioirrigation on benthic-pelagic coupling strongly differ accord-
ing the the chosen formalism, in particular in terms of the N:P ratio of
remineralised fluxes.