In a few years, the low tide landscape of Oak Harbor could change. In place of mud flats, a lush green belt could swath rocks and cover driftwood. Great blue herons stalking their next meals would look for new dining spots. Other shorebirds would abandon the area as life in Oak Harbor’s mud flats disappears.
Only an unvarigated green would remain, inviting other non-native species of plants and animals to invade.
All this change would come courtesy of one plant — Spartina anglica, an invasive species from the East Coast ravaging through Washington’s coastal counties.
Locally, groups are fighting the invasion. Marine Resources Committee, Island County Noxious Weed Control Board, WSU/Island County Shore Stewards and Beach Watchers, along with People for Puget Sound, sponsor seminars, and more importantly, digs to remove the plant. Saturday, Aug. 14, people can held remove Spartina from Oak Harbor during a community dig.
Last week, Susan Horton, who heads Island County’s Noxious Weed Control Board, scouted Pioneer Way’s waterfront for Spartina.
She found plenty.
“It’s an incredibly hardy plant,” Susan Horton said as she dug a Spartina clump from an Oak Harbor mud flat.
Horton hefted the glob of grass, roots, mud, rock and shell and hauled the offending specimen off the beach.
Spartina’s dense root system traps sediment and rock, she explained, turning mud flats into salt marshes.
“It degrades habitat,” Horton said.
A mud flat might seem desolate except for a heron or two, but just below the surface, it’s an ecosystem teeming with life.
“Quite a bit lives in mudflats,” WSU/Island County Beach Watcher Heather Leahy-Mack said Tuesday.
Clams and other bivalves are probably the most recognized mudflat residents.
“But other organisms some people might not think very exciting live there,” Leahy-Mack said. Organisms including segmented worms, snails and ghost shrimp make their homes in mud, she noted.
A mud flat is “an overall ecosystem,” Leahy-Mack said. Mudflats provide critical habitat for shorebirds as well as gray whales. The bill of each species of shorebird is just the right size to probe mud and sand for tasty morsels.
Gray whales move slowly along Whidbey Island’s east side in spring and fall, scouring mudflats. These marine mammals scoop-filter vast amounts for ghost shrimp — their preferred dinner guests. For at least one group of whales that regularly ply Saratoga Passage, Whidbey’s mudflats offer a needed pit stop on their swim from Alaskan waters to those off Baja, Calif.
“Native plants and animals are adapted to life on mudflats,” Leahy-Mack said.
Because Spartina can so swiftly trap sediment, land becomes salt marsh rapidly.
“The overall ecosystem is devastated,” Leahy-Mack said.
Such devastation can be avoided by digging. But removing Spartina from mud can be difficult. Its deep, thick root system and the mass of sediment it traps creates a heavy load to haul over driftwood and up a beach.
Saturday, Horton and others invite local residents to come with shovels, boots, gloves and wheelbarrows to help remove Spartina from Oak Harbor. And volunteers without equipment will be welcomed to deliver Spartina an eviction notice.
You can dig it
Join People For Puget Sound and Island County Marine Resources Committee for Island County Dig Days Saturdays, Aug. 14 and 28, from 9 a.m. to 2 p.m. Aug. 14, volunteers will remove Spartina from Oak Harbor. Aug. 28, they will be working on Camano Island at Iverson Spit near Stanwood. Snacks and tools provided. Families are welcome. Children under 12 must have one-on-one adult supervision. RSVP to Britta Eschete at beschete@pugetsound.org.
