TY - UNPB

T1 - Flexible anchored mats of artificial seagrass for restoration

AU - Villanueva Granados, Raul Armando

AU - Paul, Maike

AU - Schlurmann, Torsten

N1 - Funding information: This study was done within the framework of the collaborative project “SeaArt – Long term establishment of SEAgrass ecosystems through biodegradable ARTificial meadows,” made possible through funding by the Niedersächsisches Vorab and Ministry of Science and Culture (MWK) of the Federal state of Lower Saxony under Grant No. ZN3187. R.V. extends thanks to the Graduate Academy of Leibniz University Hannover for their sponsorship during the drafting of this paper. M.P. further acknowledges funding from the research project SeaStore (Diversity Enhancement Through Seagrass Restoration) from the German Federal Ministry of Education and Research under grant agreement number 03F0859A.

PY - 2023/6/2

Y1 - 2023/6/2

N2 - Seagrass restoration requires a sound understanding of the hydrodynamics around established meadows. Present know-how primarily stems from idealized artificial seagrass (ASG) attached to a fixed bed. With the goal of accessible field deployment for restoration, anchored prototype scale ASG mats (coconut mesh) were tested under differing wave conditions to analyze hydrodynamic interaction and assess the suitability of contemporary predictive models. Velocity structure and wave propagation were measured around one and two ASG mats (separated by a 2-m gap). The mats reduced orbital velocities by up to 16% (2 mats), whereby the average reduction was low (< 10%) compared to the non-vegetated conditions. Velocities increased above the ASG, with the gap enhancing velocity (up to 11%) instead of attenuating it. Wave decay followed an exponential decrease, further enhanced by the second mat. Current models did not capture the induced hydrodynamics for the full range of wave conditions tested, with the second mat increasing uncertainties. Wave decay models generally overestimated wave attenuation (up to 30%), except for longer wave periods. Nevertheless, for the full range of conditions, the models provide accurate insight into the expected magnitude of attenuation under field conditions. It is speculated that mat flexibility affects the surrounding hydrodynamics through inherent motion, with the gap contributing to the uncertainties.

AB - Seagrass restoration requires a sound understanding of the hydrodynamics around established meadows. Present know-how primarily stems from idealized artificial seagrass (ASG) attached to a fixed bed. With the goal of accessible field deployment for restoration, anchored prototype scale ASG mats (coconut mesh) were tested under differing wave conditions to analyze hydrodynamic interaction and assess the suitability of contemporary predictive models. Velocity structure and wave propagation were measured around one and two ASG mats (separated by a 2-m gap). The mats reduced orbital velocities by up to 16% (2 mats), whereby the average reduction was low (< 10%) compared to the non-vegetated conditions. Velocities increased above the ASG, with the gap enhancing velocity (up to 11%) instead of attenuating it. Wave decay followed an exponential decrease, further enhanced by the second mat. Current models did not capture the induced hydrodynamics for the full range of wave conditions tested, with the second mat increasing uncertainties. Wave decay models generally overestimated wave attenuation (up to 30%), except for longer wave periods. Nevertheless, for the full range of conditions, the models provide accurate insight into the expected magnitude of attenuation under field conditions. It is speculated that mat flexibility affects the surrounding hydrodynamics through inherent motion, with the gap contributing to the uncertainties.

U2 - 10.21203/rs.3.rs-2957238/v1

DO - 10.21203/rs.3.rs-2957238/v1

M3 - Preprint

BT - Flexible anchored mats of artificial seagrass for restoration

ER -