What Is Eelgrass?

Zostera, more commonly known as eelgrass, is a genus of seagrass native to coastal waters. Many ecologists consider eelgrass to be a vital component of coastal ecosystems, as it provides food and shelter for dozens of species, both large and small. Unfortunately, eelgrass is susceptible to wasting diseases and environmental changes, and is believed to be in decline throughout much of its natural habitat. In North America, many restoration programs exist to preserve this important seagrass and the many creatures who depend on its existence for survival.

A very plain and easily overlooked plant, eelgrass resembles ordinary land grass. Consisting of several shoots spreading out from a central root, Zostera can grow into vast seafloor jungles that provide nutrition, homes, and camouflage for many different species. Despite its essential role in the presence of coastal ecosystems, the grass is extremely susceptible to a type of pathogenic illness known as eelgrass wasting disease. In the 1930s, approximately 90% of all beds were damaged or destroyed by the wasting disease, which continues to affect some beds in the 21st century. Many of the conservation programs dedicated to the preservation of the grass seek to restore the health of wasted beds after an outbreak of the illness.

Within the gently undulating jungles of this marine plant, a wealth of life and activity occurs. Eelgrass beds are visited by a variety of grazing species from both the murky world below the water and the flourishing world above. Swans, green turtles, snails, and crabs prefer to snack on the tasty grass itself, while sea slugs, periwinkles, and marine flatworms opt to munch on the bacteria and sponges that grow on the blades of grass. Bay scallops grow safe from predators beneath the protective layer of grass, and were nearly wiped out following the 1930s grass epidemic. Even seahorses find shelter and food in the marine forest, wrapping their tails around the sturdy central root in order to stay in place during rough waters.

Like most marine plants, eelgrass also serves a vital function in the preservation of the ocean itself. Through photosynthesis, the grass helps reduce harmful chemical increases in both the water and the air. The grass also absorbs potentially dangerous elements such as nitrogen from waste water runoff, using the fuel provided by the mineral to grow. Eelgrass also traps and cements particulate matter into its beds, which can help prevent over-sedimentation in the water itself.

The many important functions of this simple plant have lead many ecologists and environmentalists to call for serious protective action to ensure its survival. By educating boaters and divers about proper behavior around grass beds, some conservation groups hope to reduce external human-caused damage to the grass. Other groups focus on monitoring the health of plants, isolating infected specimens, and re-populating depleted beds. Conservation groups are particularly popular along the North American Atlantic coast, where the grass is considered vital to the prosperity of the fishing industry.