Contaminant Trends in the Southern California Bight: The Coast is Cleaner

Mearns, Alan J.; ,

Contaminant Trends in the Southern California Bight: The Coast is Cleaner

by Alan J. Mearns, NOAA, Seattle, United States,

Document Type: Proceeding Paper

Part of: Coastal Zone '93

Abstract:

Data from local, regional and federal coastal monitoring programs were used to assess long-term trends and spatial extent of chemical contamination in sediments, shellfish, and fish of Southern California and northwestern Baja California, Mexico. The highest concentrations of most contaminants including radionucleides, metals, chlorinated hydrocarbons, and petroleum hydrocarbons occurred during the 1960s and early 1970s. Levels of most contaminants have since declined, in some areas by as much as 99 percent. Decreases are commensurate with atmospheric and wastewater source control programs initiated during the 1970s. Metals, other than lead (Pb) and silver (Ag), were never a regional problem in terms of resource contamination. With one exception, remaining 'hot spots' are in harbors and marinas while most water outfall areas are now free of significant or serious chemical contamination. The 'path forward' should focus on management of the remaining hot spots, improved resolution and coordination of contaminants, and resource-use monitoring and implementation of an Integrated Coastal Management approach as suggested by the National Research Council ((NRC), in press).

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