Publication
Hydrodynamics in Indo-Pacific seagrasses with a focus on short canopies
Publisher:
Walter de Gruyter GmbH
Date:
22-11-2018
DOI:
10.1515/BOT-2017-0037
Abstract: Seagrass hydrodynamic regimes are important to understand and also to guide seagrass restoration, which is of great interest in Indonesia because of environmental threats to the exceptionally high seagrass species richness. Hydrodynamic regimes influence the physical stability of seagrass beds, sedimentation rates, and the advection of nutrients and food to seagrasses and associated organisms. In a flume, we determined the effect of canopies of Cymodocea rotundata , Enhalus acoroides , Halodule uninervis , Syringodium isoetifolium and Thalassia hemprichii on water velocity, turbulence, turbulence intensity and shear velocity. The taller canopies of Enhalus and Cymodocea slowed water flow, but the shorter canopies ( cm) had little effect. Seagrasses did not influence turbulence and turbulence intensity (turbulence normalized to mean velocity) but they reduced shear velocity U*. Our results indicate that Enhalus is a good candidate for transplantation in terms of reducing mean water flow and shear velocities, but that Halodule should also be considered as it also reduced shear velocities and it spreads quickly after transplantation. Our results extend the understanding of seagrass-hydrodynamic relationships to include very short canopies, unlike the taller canopies studied to date.