A model for macroalgae and phytoplankton growth in the Venice Lagoon

Abstract

The definition and a first parameterization of a dynamic model of macroalgal growth is described, aimed at including this species and related physico-chemical variables in a more comprehensive 3-D eutrophication-diffusion, water-quality model of the Venice Lagoon. Relevant physicochemical factors affecting macroalgal and phytoplankton competition and succession have been analyzed as a function of physiological and trophic conditions. Results of simulations show that while phytoplankton response to growth factors is more intense and of shorter duration, internal nutrient storage in macroalgae stabilizes the growth process and makes macroalgal communities relatively more independent of variations of chemical and external forcing functions. The model provides results which appear to be qualitatively and quantitatively consistent with available functional in situ measurements. © 1995