The Lower Elwha Klallam Tribe, in partnership with Pacific Northwest National Lab (PNNL), has planted more than 43,000 eelgrass plants in Port Angeles Harbor over the past decade, stemming from what was originally a one-time eelgrass salvage effort.
In 2017, the U.S. Navy was building a pier on the Coast Guard base in the bay to accommodate large vessels that escort naval submarines through the Strait of Juan de Fuca.
“It was a pretty large pier and was going to have some environmental impact,” said Matt Beirne, the tribe’s natural resources director.
Mitigation projects were developed, including salvaging marine plants from the pier construction site. Eelgrass meadows, designated as critical habitat in the state of Washington, 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.
Divers from the tribe and PNNL harvested about 7,500 plants from the site in 2017, including eelgrass. Half were planted on another shoreline in the bay, and the other half were placed in outdoor tanks at PNNL’s facility to grow before being planted.
To everyone’s surprise, the number of eelgrass plants at PNNL doubled the first year. By 2019, the number had tripled, Beirne said.
Since then, the tribe, PNNL and volunteers have planted 6,000-9,000 eelgrass plants in the bay every two years. This spring was the final effort in which 17,205 individual eelgrass shoots were planted, bringing the project to 43,205 plants moved.
“The fact that we would harvest half the tank for our periodic plantings and two years later have the same number or more meant we could provide much more benefit that we initially thought,” said John Vavrinec, a senior research scientist at PNNL.
“It has been a truly exciting and rewarding project for our staff and a great collaboration with PNNL,” Beirne said.
The plantings also have benefited from the tribe’s numerous shoreline restoration projects in the bay, he said.
Over the years, the tribe has removed structures from the Ediz Hook shoreline, such as creosote, concrete and riprap, then restored the beaches with a gravel and sand mix. Some projects involved the use of sand that had accumulated on the Elwha River following dam removal.
“It has created this great positive synergy with the subtidal recolonization of eelgrass,” Beirne said. “A lot of that sand has been transported from the beach down into the shallow subtidal areas by long-shore drift processes, and that’s created this really nice habitat for natural recolonization.”
Eelgrass shoots are tied with jute twine onto rebar, which is then placed in the subtidal areas of Port Angeles Harbor so the eelgrass can create habitat for juvenile salmon and other marine life. Story and photos by Tiffany Royal
