Home Archived April 8, 2019
USGS Pacific Coastal and Marine Science Center
Pacific Coastal and Marine Science Center

Fate of Dredge Disposal Material and Polluted Sediment, Offshore Honolulu, Hawaii

Maps & Images
Raw Data


Perspective look at Mamala Bay
Perspective overview of western Mamala Bay between Ewa and Diamond Head. The scale across the bottom of the image is approx. 12.5 km. The vertical exaggeration is 5x. This image was created from multibeam data collected in 1998.


For more than a century, material dredged from Pearl and Honolulu Harbors has been dumped in Mamala Bay off Oahu, Hawaii. Human activities add other materials to the bay as well: wastewater from Honolulu and its suburbs, shipyard contaminants and lead paint from ships, agricultural fertilizers leached from fields. It is not known how the dredged material and contaminants are affecting the environment.

In 1991, the USGS began studying the dredged material in cooperation with the U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency (EPA). Our initial studies focused on mapping the material's distribution and thickness, determining its physical and chemical makeup, assessing its effect on seafloor life, finding out whether it is being moved by currents, and ultimately determining the fate of dredge material and associated contaminants. The results of our studies are available through this web site and a series of reports and publications.

index map
Index map of study area.



Of general interest, enter here for finished products including images, maps, photos, and other viewable files of the dredge disposal site in Mamala Bay.


For those who want to read about the project, enter here for publications and reports including USGS Open File Reports, online papers and abstracts, and other bibliographical references of interest.


For the down and dirty, here is the raw data including core descriptions, geochemical data, arc format files, shipboard metadata, and much much more.


This area includes links to the USGS and all of our partners in this project.

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For more information, please contact:
Mike Torresan

U.S. Geological Survey
2885 Mission Street
Santa Cruz, CA 95060

U.S. Department of the Interior | U.S. Geological Survey
Path: mamalabay/
More information: Contact USGS
Content last modified in ~2000