Status of the crayfish stocks in Pine Lake, King County, Washington five years after the discovery of the invasive red swamp crayfish Procambarus clarkii (Girard, 1852)

In 2005, I conducted a baseline survey of crayfish stocks in Pine Lake, King County, Washington, which was invaded by red swamp crayfish (Procambarus clarkii) during the 1990s. Irrespective of the gear type used for sampling, the invader outnumbered the native signal crayfish (Pacifastacus leniusculus). This is the first account of an invasive species of crayfish dominating the signal crayfish inside of its natural range.