Introducing biofouling effects in a lagrangian-tracking particle 3d model

One of the most challenging problems in the study of oceanographic pollution is the fate of macroplastics. A good understanding of the litter pathway since the moment they enter the sea is essential to reduce environmental hazard, also to withdraw them before they become microplastics. For this purpouse we use a Lagrangian tracking model to evaluate the dispersion and accumulation in coastal zones of marine macroplastics.\ 3-dimensional model, named MOHID-Lagrangian tool, is prepared to estimate particle trajectories given a hydrodinamic field. Also it includes windage effects, coastal beaching or waves effect through Stokes drift. To take into account the effects of algae and mollusc attaching to our lagrangian particles we added a biofouling term. This term modify the sinking velocity of particles by increasing its density. We relate the variation of this density to the attached biofilm growth, interpreting this as a function of ambient algal concentration, encounter rate and other algae properties.