Willapa National Wildlife Refuge
The Willapa Bay estuary contains more than 80,000 acres of valuable intertidal mudflats and native salt marsh habitat. Nestled within this important estuary is 14,000 acre Willapa National Wildlife Refuge, which is home to more than 250 bird species and annually hosts some of the largest populations of shorebirds on the West Coast. Audubon Important Bird Areas located partly or entirely within the boundaries of Willapa Refuge include Shoalwater Bay (also known as South Willapa Bay) and Ledbetter Point.
The refuge is threatened by an invasive cordgrass, Spartina alterniflora, which rapidly infests intertidal mudflats and salt marshes. The cordgrass forms dense monospecific stands that trap sediments and alter hydrologic processes. Mudflats are crucial habitat for shorebirds, waterfowl, clams, crabs, and oysters. In the past decade alone, Spartina has taken over 11,000 acres of the Willapa Bay estuary, and is expanding at the alarming rate of 20 percent per year. Already, Willapa Bay has the largest Spartina infestation of any estuary on the Pacific coast.
Threat to Birds
Conversion of intertidal mudflats and native saltmarsh habitats to stands of Spartina threatens to devastate imperiled shorebird populations that rely on the increasingly rare coastal mudflats as their last remaining habitat. The Spartina infestation represents a particularly acute threat to already-declining populations of the Short-billed Dowitcher, an Audubon WatchList species. Other WatchList species harmed by the Spartina infestations in Willapa Bay include Pacific Golden-Plover, American Golden-Plover, Whimbrel, Marbled Godwit, and Red Knot.
A Success Story
This refuge’s succesful fight against invasive species has been due to a communitywide effort of the refuge staff, the oyster industry, and elected officials and others. The refuge was given $7 million over six years for eradication efforts. The amount of cordgrass, Spartina alterniflora, in the refuge has gone from a staggering 11,000 acres to less than 100 acres. Refuge staff are still working to eliminate Spartina completely. Since reducing invasives, Willapa has seen the return of several shorebirds and other wildlife.