The mechanical treatment occurred at the Dow tidal marsh therefore one control and one treatment area was setup for consistent monitoring before and after the shredding (Madsen 1997).Water from the San Joaquin River flows into the tidal marsh as the Bay tide fluctuates posing as a potential variable for change in water quality. The water quality data collected at the Antioch Marina pier acts as a reference for comparing the water quality within the tidal marsh and the connected San Joaquin River. Samples were taken from the pier at three specific sites.