In February 1991, the Habitat Investigations Program of the Coastal Zone and Estuarine Studies (CZES) Division, in cooperation with the U.S. Navy, began monitoring to assess environmental conditions at the project site before, during, and after pier replacement. Major elements evaluated included water quality, eelgrass distribution and density, juvenile salmonid migrations, and fish abundance. We concluded the following, based on investigations in this first year:
- Water quality measurements, including those taken during dredging operations and pier construction, were unexceptional in range and magnitude, and revealed no long-lasting effects of pier replacement activities on dissolved oxygen, salinity, temperature, or turbidity.
- The distribution and density of eelgrass near the fuel pier were probably not affected to any measurable extent by dredging in February and March 1991. However, completion of the new fuel pier and removal of the old fuel pier are likely to affect eelgrass distribution and density and, consequently, the outmigration of juvenile salmonids through the area. Eelgrass should be monitored regularly throughout and after completion of the fuel pier replacement project because changes in eelgrass distribution and density are readily detectable and can be explicit indicators of important effects of the pier on juvenile salmonid migrations.
- Spring beach-seine sampling on both sides of the Manchester fuel pier clearly indicated the presence of migratory juvenile chum, coho, and chinook salmon. Fish size and presumed direction of travel suggest that some portion of the juvenile salmonid stocks using the area are successfully migrating through or around the fuel pier. Cutthroat and rainbow (steelhead) trout were also caught near the fuel pier but were considerably less abundant than other salmonids.
- Twenty-seven fish species were collected by beach seining. Of the 22 non-salmonid species captured, many are suspected predators of juvenile salmonids, including the 5 most numerous non-salmonid species caught: shiner perch, striped seaperch, Pacific staghorn sculpin, English sole, and starry flounder.