Effects of wave-driven plant reconfiguration on light availability to seagrass

Seagrasses are considered foundation species in marine and estuarine ecosystems by contributing biomass, habitat, and damping waves and currents. Globally, seagrass health and primary productivity are particularly threatened by factors that affect light availability, such as shading by algae, self-shading, and increased water column turbidity. This study focuses on how plant motion and reconfiguration lead to shading of an individual plant and its neighbors, and how wave/flow conditions, plant flexibility, and plant density affect light availability along a seagrass blade. We use a simple ray-optics shading model with the numerical model developed by Luhar and Nepf (2016) for a flexible blade under wavy flow to understand how phase-resolved plant behavior affects light availability as a function of vertical location in the water column. The results help us understand whether certain flow events or plant properties lead to increased shading, and what conditions are optimal for maximizing the light exposure to seagrass' photosynthetic tissue.