CENTRAL PARK, Wash. - New Zealand mudsnails were recently discovered in the lower Chehalis River approximately 2.0 miles south of Central Park and approximately 2.5 miles east of Cosmopolis. This is the first discovery of New Zealand mudsnails in the Chehalis River Basin.
The invasive species was found at the Washington Department of Natural Resources Blue Slough Access area.
The NZMS were found in mud around a spring at the site. The New Zealand mudsnails were collected during low tide, the site is inundated with water at high tide. The site is tidally influenced and the water is brackish. The extent of introduction is unknown.
The collectors also sampled at the Washington Department of Fish and Wildlife boat ramp, just up steam of the Blue Slough site, adjacent to the SR107 bridge (about RM 13.2). No New Zealand mudsnails were found. The Chehalis River is brackish here as well.