Flowering Underwater Seagrass

In the shallow waters of eastern Long Island Sound, you’ll find meadows of eelgrass—long, bright green ribbon-like strands that sway beneath the surface. Though often mistaken for seaweed, eelgrass is a flowering underwater plant that grows completely submerged and provides vital habitat for marine life.

Eelgrass produces sexually and asexually. Plants flower in the late spring when Long Island Sound’s waters warm. Then, flowers are fertilized by drifting pollen, and reproductive shoots called spathes eventually break off of the main stem and float to the surface releasing seeds. For asexual reproduction, a plant stem will send out new shoots from its nodes, sometimes creating entire eelgrass beds consisting solely of clones from the original plant.

Why is Eelgrass Important

Eelgrass provides important ecosystem services. Here are examples:

• Serves as important nursery habitat, refuge from predators, and food source for key recreational and commercial fish species.
• Prevents shoreline erosion by stabilizing sediment and reducing the intensity of wave impacts.
• Captures and stores carbon (i.e., carbon sequestration or known as blue carbon  [PDF] )
• Removes excess nitrogen from the water column (i.e., denitrification)

The Long Island Sound Eelgrass Management and Restoration Strategy provides guidance for short and long-term actions that should be taken to manage and restore eelgrass meadows in Long Island Sound and act as a resource for other estuaries in the region facing similar issues.