K1-95-HW: Cruise Report 1995 - Preliminary results.

Phase III: Sediment Chemistry and Biological Sampling Survey

M.E. Torresan, M.A. Hampton, J.H. Barber, Jr., and F.L. Wong

U.S. Geological Survey Open-file Report 95-839

1995

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards. Any use of trade names is for descriptive purposes only and does not imply endorsement by the USGS.

Summary 1, 2
Introduction
Study Area
Previous Studies
  Designation
  Monitoring 1, 2
Methods
  Vessel
  Navigation
  Sampling
  Subsampling 1, 2
Results
Acknowledgments References 1, 2

Figures
1 Location
2 Box corer

Tables
1 Stations
2 Samples
3 Analyses
4 Bioassay

Appendices
1 Box Cores
2 Custody: Quanterra
3 Custody: Batelle

Contact:
M.E. Torresan
M.A. Hampton

Infobank
K1-95-HW

Phase 1, conducted in 1993, inventoried the seafloor via remote sensing. Sidescan sonar and subbottom profilers characterized the seafloor in and around the disposal sites, and the resulting products reveal the character and extent of the dredged material. These data were used to plan Phase 2 in 1994, a sampling program that employed subbottom profilers, video and still photography, and seafloor sampling to ground truth the sonar mosaic and identify the seafloor substrates responsible for the various acoustic signatures on the sonar images and subbottom profiles. Box coring provided the samples necessary to distinguish dredged material from native sediment, and for the chemical analyses used to determine contaminant concentrations. Phase 3 studies conducted in June of 1995 consisted of box core sampling for chemical and biological analyses. Specific studies include: infaunal taxonomy and population density, bioassay/bioaccumulation, sediment chemistry, and post-disposal resuspension and transport.

The 1995 survey, conducted June 14 through 17, resulted in the collection of 39 box cores from 20 different stations. Multiple box cores were composited at 7 different locations occupied in 1994, to provide the material required for the 7 bioassay and bioaccumulation analyses currently underway (Figure 1). Seventeen of the 20 stations occupied provided the biological samples for the benthic infaunal identification and population density study conducted by Dr. Julie Brock of the University of Hawaii, and the sediment chemistry analyses conducted (and completed) by Quanterra Environmental Laboratories (Figure 1). Seven of the 20 stations occupied in 1995 were occupied in 1994, and provide the data for direct comparison of sediment chemistry at the same sites from two consecutive years. The sum total of the data collected from all three phases of the monitoring program will provide the U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency with the information required to make informed decisions as to the management of the South Oahu disposal site in Mamala Bay.

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