Northwest Fisheries Science Center

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Document Type: Contract Report
Center: NWFSC
Document ID: 6588
Title: Environmental monitoring of the Manchester naval fuel pier replacement, Puget Sound, Washington
Author/Editor: Douglas B. Dey
Publication Year: 1991
Publisher: National Marine Fisheries Service
Contracting Agency: U.S. Department of the Navy, Naval Facilities Engineering Command. Silverdale, Washington
Contract Number: N62474-91-MP-00758
Pages: 60
Date: 11/01/1991

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:  

  1.   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.
  2.   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.
  3.  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.
  4.  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.