Vertical biomass distribution drives flow through aquatic vegetation

Abstract

Seagrass meadows represent important ecosystems providing many services, which have been disappearing, mostly due to anthropogenic reasons. Restoration attempts require deep understanding of the hydrodynamics involved, as well as the role of the biomechanical traits of the plants. This study analyzes the utilization of artificial elements as seagrass surrogates and their effect on flow. The surrogates are tested against a unidirectional current in a circular track-flume at velocities of 5, 10, 20 and 30 cm/s for three different vertical biomass distributions to assess the influence of biomechanical traits. Results show that the vertical biomass distribution plays an important role in the reduction of current velocity. The low shoot density tested also proved to be enough to onset current reduction utilizing artificial elements. This proves that ecosystem services such as sedimentation and energy dissipation are reproducible with artificial elements, and can be used as means for restoration and protection.