National Status and Trends (NS&T) Mussel Watch Program provides status of and temporal trends of coastal contaminant conditions. Bivalve tissues are analyzed for a suite of about 500 legacy and emerging chemicals of concern. In addition, bivalve tissues are assessed for histopathology and gonadal index. The Program’s data, metadata and information products are managed within the guidance provided by NOAA’s Integrated Ocean Observing System (IOOS) and the National Monitoring Network, as recommended by the 2004 Ocean Action Plan. This document describes the Standard Operating Procedure (SOP) for mussel collections in Oregon State. Since 1986, Mussel Watch has established about 300 sites nationwide and 28 of these are in Washington State where the Mytilid mussels (blue mussels) are the target sentinel bivalve species. In Washington, mussels are handpicked by walking to the site at low tide.