The summer boating season is a wonderful time for families and visitors to enjoy time on the water together; however, most of the floating eelgrass is due to boat propellers and anchors dragging through the grass.  Boat propellers chop it into large quantities all over the river, as the grass is up to four (4) feet tall with up to 15 leaves per plant.  Dragging anchors through the seagrass tears it out by the roots, damaging the grass beds and adding to the volume of floating grass in the river.
In the fall, as days get shorter and sunlight is less plentiful, you will see additional floating grass appear.  The grass directs its energy into growing rootlike structures called rhizomes increasing the spread of new grass plants and will release most of their leaves, much like an oak or maple tree.