The Lower Elwha Klallam Tribe and Pacific Northwest National Laboratory (PNNL) are restoring eelgrass beds in Port Angeles Harbor. Marine life habitat has been degraded, in part by decades of wood waste deposition.
The effort started by removing about 3,600 eelgrass shoots as part of a mitigation agreement between the U.S. Navy and the Lower Elwha Klallam, Jamestown S’Klallam and Port Gamble S’Klallam tribes. The Navy is constructing a pier in the harbor to accommodate nuclear submarine escort vessels.
If the eelgrass had not been removed, it likely would have died due to shading, said Matt Beirne, the tribe’s natural resources director. During the eelgrass salvage, surfgrass, another important native species of seagrass, was discovered under the pier that had not been known to exist within Port Angeles Harbor. About 4,000 surfgrass plants were salvaged in addition to the eelgrass.
After divers with the tribe, PNNL and Washington SeaGrant harvested the shoots, about one third of them were planted on two test plots along Ediz Hook.
One test plot was planted along the shoreline in natural conditions and the other was planted on a thin layer of sand that covers wood waste. The latter site is being studied to determine if sand caps on wood waste can improve habitat and if eelgrass can grow in such conditions. The sand cap project was completed separately by a group of local governments and corporations who are examining potential restoration projects in Port Angeles Harbor.
The rest of the shoots were transported to PNNL’s Marine Sciences Laboratory in Sequim, where they were planted in large outdoor tanks designed for eelgrass nurseries. In 2019, shoots from the tanks will be harvested and transplanted to restoration sites in the harbor.
Eelgrass meadows buffer the effects of ocean acidification, stabilize the nearshore, and are used by salmon, other fish, invertebrate species, marine mammals and birds for foraging, spawning and rearing.
“Planting these shoots in other areas of the harbor that have been formerly degraded by log rafting, wood waste and other activity will benefit from eelgrass added to these areas,” Beirne said.
Another purpose of the project is to restore eelgrass on state-owned aquatic lands to contribute to the Puget Sound Partnership’s goal of increasing eelgrass by 20 percent by 2020.
The tribe has participated in other restoration projects within Port Angeles Harbor, including restoring nearly a mile of Ediz Hook shoreline since 2012 and by removing old dock structures and pilings and replacing them with clean sand and gravel, dune grass and woody debris.
Watch a video on how eelgrass is planted in the tanks at PNNL.