Light is probably the single most important factor affecting bay grass growth.
There must be enough light reaching the bottom of a body of water for bay grasses to grow. In areas of high suspended solids and algae, almost all available light is absorbed and scattered by suspended solids and algae, preventing growth of bay grasses. However, when there are too many nutrients in the water, bay grasses suffer. The excess nutrients promote the growth of algae, which reduces the amount of light available for bay grass survival. Small particles in the water, like silt, scatter and absorb light as it passes through the water column.