Light available to the seagrass <italic>Zostera marina</italic> when exposed to currents and waves

Abstract

Aquatic organisms are regularly exposed to varying degrees of hydrodynamic forces such as currents and waves. Seagrasses, which are rooted in the sediment, have flexible leaves, allowing them to sway back and forth with waves and deflect with currents. Furthermore, seagrasses can acclimate to local hydrodynamic forces exerted upon them by changing their morphology, which may benefit the organism via reduced drag, but may also bring disadvantages such as increased self-shading. We examined the interaction between water flow and morphology of the seagrass <italic>Zostera marina</italic>, and how this interaction affects light availability to the plant. We also assessed carbon and nutrient content of <italic>Z. marina</italic>, as the uptake of these constituents has been linked to hydrodynamic conditions and sediment composition. Our results indicate that local hydrodynamics and sediment composition induce morphological variation in the seagrass <italic>Z. marina</italic>, and that this variation influences light availability to the seagrass canopy.