After investing millions of dollars to restore the Skokomish estuary, the Skokomish Tribe is monitoring the habitat to measure its success.
The tribe purchased and restored nearly 400 acres in the estuary starting in 2007, after the property operated as a farm and a private hunting club for nearly 80 years.
“Salmon need estuaries to grow,” said Lisa Belleveau, the tribe’s habitat biologist. “If they don’t have a healthy estuary to grow in before they head out to the ocean, their likelihood of being able to survive ocean conditions and return as adults is low.”
The tribe has been collecting data for more than a decade of data following the restoration of the estuary. Annually from 2011-2020, and now every other year, the tribe has been observing changes happening in the estuary, including sediment levels and types of vegetation.
The tribe monitors 15 sites (3 plots per site) throughout the estuary and in reference marshes, observing the plants present, salinity levels in the soil, and how the estuary has increased or decreased in elevation according to the height of the sediment.
“Sediment helps build elevation that creates an environment capable of supporting salt marsh vegetation,” Belleveau said.
The biggest takeaway has been how fast things have changed and adapted in the estuary, she said.
After the first four years of monitoring, by 2015 the estuary vegetation had started to resemble adjacent reference marshes and continues to do so, she said.
Preliminary analysis of the data includes determining plant species that are tolerant of varying salinity levels and elevations and where they like to settle, she said.
She’s also looking at the effects of salt water submergence time on vegetation in the restoration areas versus reference areas, areas on the east and west side of the estuary that were not diked or farmed.
Some plants can handle a certain amount of saltwater submersion while some can’t, helping Belleveau better understand the various vegetation communities she’s observing and why some plants are flourishing and others are not.
As for the salmon using the estuary, overall, the data suggests that fish are utilizing the restoration areas, said Kevin Swager, the tribe’s finfish biologist.
“We do find most of the salmonid species in those areas,” he said.
Skokomish habitat biologist Lisa Belleveau, left, and habitat technician Shae Holy monitor vegetation growth and sediment deposit in the Skokomish estuary. Photo and story: Tiffany Royal
