The 2023 Annual International Workshop on Physical Processes in Natural Waters (PPNW2023). This year the conference was held in Brescia, Italy, in the period 19-23 June 2023 and hosted by Università degli Studi di Brescia.

The PPNW workshops focus on physical processes in inland and coastal waters and their interaction with biogeochemical, atmospheric, and groundwater processes. PPNW is an open workshop that actively seeks collaboration with related fields such as physical oceanography, atmospheric sciences, and engineering.  This moderate-sized meeting of 40-60 participants is designed to provide a collaborative atmosphere with an effective balance of presentations and time for discussion.

Within this context, Dr. Serra, in collaboration with Dr. Colomer and Dr. Barcelona, contributed to PPNW 2023 with an oral presentation entitled “Stem stiffness behaviour in an oscillatory flow submerged canopy patch”. Dr. Serra et al. presented findings on the behavior of seagrass canopies in oscillatory flow environments. Their study highlights the ecological significance of seagrasses in coastal systems, where they play a crucial role in sheltering the seafloor from waves and currents, improving water quality, providing habitat, sequestering carbon, and stabilizing sediment. Despite their importance, seagrass meadows have been in decline due to human activities such as anchoring, dredging, trawling, and sewage outflow, leading to fragmented landscapes that alter coastal hydrodynamics.

The research focused on understanding how different structural characteristics of seagrass patches, such as plant flexibility and patch length, influence hydrodynamic interactions. Laboratory experiments conducted in an oscillatory flume demonstrated that flexible plants tend to move with the flow in the upper canopy layer, while rigid plants exert significant drag along their entire stem length, leading to higher turbulent kinetic energy production. This distinction suggests that rigid plants are more common in sheltered areas, whereas flexible plants thrive in exposed areas with strong flow energy. The study also explored how varying wave frequencies affect the behavior of flexible and rigid plants.

These findings provide valuable insights into the resilience of seagrass meadows and their ability to adapt to changing environmental conditions. Understanding the optimal patch length scales, meadow densities, and plant distributions can help in the conservation and restoration of these vital coastal ecosystems. The research underscores the need for continued efforts to protect and restore seagrass habitats to maintain their ecological functions and benefits.