Teresa Serra has directed the Final Master's Project of Aina Barcelona, entitled “Sediment trapping by a model flexible submerged vegetation in an oscillating flow”, defended on 19 October 2018. This study has been conducted within master's degree in Oceanography and Marine Environmental Management of the University of Barcelona, and of the FragmentUm Project.

In this study, Aina Barcelona explains that vegetation in coastal habitats (mangroves, saltmarshes and seagrass beds) acts as ecosystem engineers for their ability to modify the local hydrodynamic conditions and has an important protection function for the coastline. Aquatic vegetation reduces sediment resuspension and increases sediment retention stabilizing the bed by absorbing the kinetic energy and reducing the wave velocity. The study aims to (1) describe the role of submerged flexible canopy models in trapping sediment particles from allochthon sources under oscillatory flow, (2) quantify the effect of the plant leaves on trapping sediment particles, (3) determine the role of the canopy density on the sedimentation of particles on the bottom (4) determine the distribution of the suspended sediment particles for different hydrodynamic conditions. Laboratory experiments were carried out in a flume using five different canopy densities (0, 127, 318, 637 and 955 plants·m²), two frequencies (0.7 Hz and 1.2 Hz) and eight wave amplitudes (1.2, 1.5, 2.0, 2.2, 4.5, 4.7, 5.0, 5.6 cm). This work shows that the cover of meadows does not affect the sedimentation within the canopy bed, but instead it determines the balance between the suspended sediment that remains on the water column inside the canopy and the sediment trapped by the leaves. The denser the canopy the greater the percentage of particles trapped by the leaves. Moreover, for TKE above 0.36 cm2s-2, corresponding to covers above 52%, the trapping by the leaves of small and medium size particles has not the same concentration, being greater for small particles than for large particles.

This research was funded by the University of Girona, through the grant MPCUdG2016-006 and by the Ministerio de Economía, Industria y Competitividad of the Spanish Government through the grant CGL2017-86515-P.