In many marine sessile organisms (for example sponges and stony corals) the skeleton is formed by an accretive growth process, where layers of material are secreted on top of each other in a surface normal deposition process. In many of these organisms the growth process exhibits a strong morphological plasticity due to di!erences in exposure to water movement. In general, many of these organisms tend to form thin-branching growth forms under sheltered conditions, while the growth form gradually transforms into a more compact shape when the exposure of water movement increases. In this paper, we investigate this phenomenon by combining a three-dimensional simulation model of radiate accretive growth driven by the local availability of simulated food particles and a model, based on the lattice Boltzmann method, for simulating food particle distributions caused by a combination of #ow and di!usion. In the simulations two di!erent models of a suspension feeder with accretive growth were compared. In the "rst model, the deposition process is exclusively driven by the local availability of food particles, in the second model the deposition process was determined by the combination of local amount of contact to the environment and availability of food particles. In the simulations it was found that hydrodynamics has a strong impact on the overall morphologies which develop in the accretive growth process. In the model exclusively driven by the local availability of food particles, column-shaped objects emerged under di!usion conditions, while more spherical and lobed object were found for the #ow-dominated case. In the simulations, the PeH clet number was varied independently from the Reynolds number, which was kept at a relatively low constant value. In a range of increasing PeH clet numbers, indicating an increasing in#uence of hydrodynamics, the simulated morphologies gradually transformed from thin-branching ones into more spherical and compact morphologies in the model where deposition was controlled by the local availability of food particles and the local amount of contact with the environment.