Eelgrass (Zostera marina)
Eelgrass native to Whatcom County marine waters has green, grass-like blades
about 1/2 inch wide and 3 feet long. Eelgrass is found submerged (underwater)
or floating primarily in colonies. These colonies are referred to as eelgrass
"beds". Eelgrass is actually a flowering plant, not a seaweed.
grows in the muddy or sandy substrate of the shallow sub-tidal
zone, down to a depth of approximately 22 feet in the Northwest.
Eelgrass grows throughout the Puget Sound, the Pacific and Atlantic
Coasts, and in Europe. In Whatcom County, eelgrass is found along
much of the shoreline, particularly near Point Roberts, Drayton
Harbor, Birch Bay, Lummi Bay and around Portage Island.
commonly reproduces by means of vegetative propagation. In this
type of propagation, the plant sends out rhizomes (horizontal,
underground stems) that send up new shoots of eelgrass. In this
way, eelgrass spreads quickly over a small area, just like the
grass in our lawns. Eelgrass can also spread by seed, which is
a slower method of reproduction, but can broadcast offspring over
a greater distance.
provides valuable forage, spawning and refuge areas for a number
of other marine species. Eelgrass fills an important function in
the marine foodweb at two levels. Eelgrass is directly consumed
by organisms such as waterfowl, urchins, worms, snails, and microorganisms.
In addition, many other species (such as salmon, crabs, and heron)
consume the organisms that live in the eelgrass colonies.
Eelgrass provides a spawning
habitat for Pacific herring, which lay their eggs on the blades
of eelgrass. Eelgrass beds are also a critical nursery area for
juvenile salmon and cod which seek protection within the beds from
Colonies of eelgrass provide
a protected habitat for many marine species seeking refuge from
potential predators. Eelgrass can also protect animals from overheating
caused by exposure to solar rays in shallow water during low tides
and in shallow areas. On tidelands, animals bury themselves underneath
mats of eelgrass to avoid dehydration.
Economic Value: Eelgrass
has historically been used for a variety of human needs such as
food, basket weaving, compost, bedding, insulation and high-grade
paper. Most industries stopped processing eelgrass in 1930-31 when
the Wasting Disease nearly wiped out eelgrass populations along
the Atlantic Coast of North America and Europe.
One of the most important
current economic values of eelgrass in Whatcom County is the habitat
provided for salmon, herring and shellfish, which are or have been
commercially harvested in Whatcom County.