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

Results acquired to date show the effectiveness of integrated assessment. Sidescan sonar shows that the dredged material is characterized by isolated, high-backscatter, circular to subcircular footprints interpreted as individual disposal events. The footprints are concentrated over the sites and form a high-backscatter blanket that covers the low-backscatter native sediment mantling the seafloor. These data imply that much of the disposed material reaches the seafloor, and does not completely disperse in the water column.

Box cores and x-radiographs differentiate the dredged material from the native sediment. Dredged material comprises a heterogeneous mixture of cohesive, olive-gray mud that is mixed with sand to cobble-size rubble, which is responsible for its high-backscatter character. Low backscatter native sediment is a beige, bioturbated, muddy carbonate sand, generally devoid of coarse clasts. Bioturbation is ubiquitous in native sediment, and in some instances is present in the overlying dredged material. This implies that at least some organisms are capable of surviving in the dredged material. Video and still photographs and some 3.5-kHz profiles show that much of the seafloor is covered by a variety of wavy bedforms, ranging from symmetrical to asymmetrical ripples. The bedforms show that current activity, possibly internal waves, may be a mechanism for secondary transport. Photography also shows that the bottom is littered with a variety of debris types including wire, barrels, military ordnance, refuse, and carbonate reef debris.

The chemical analyses conducted on seafloor sediment and dredged materials do not yield definitive results, but generally, analyte concentrations are low to nondetectable. In some instances specific contaminants exhibit higher concentrations in native sediment, relative to dredged material and vice versa. In other instances certain analytes show both higher and lower concentrations in both native sediment and dredged material. Conclusions regarding the biological analyses are pending completion of those studies.

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