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NOAA's national marine sanctuary offices and visitor centers are currently closed to the public, and in accordance with Executive Order 13991 - Protecting the Federal Workforce and Requiring Mask Wearing, all individuals in NOAA-managed areas are required to follow Centers for Disease Control and Prevention (CDC) guidance on mask-wearing and maintaining social distances. Sanctuary waters remain open for responsible use in accordance with CDC guidance, U.S. Coast Guard requirements, and local regulations. More information on the response from NOAA's Office of National Marine Sanctuaries can be found on

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Research Technical Report

Chronic Oiling of Marine Birds in California By Natural Petroleum Seeps, Shipwrecks, and Other Sources

Henkel, L.A., H. Nevins, M. Martin, S. Sugarman, J.T. Harvey, M.H. Ziccardi (February 2014)

Marine Pollution Bulletin 79:155-163


We assessed temporal and spatial patterns of chronic oiling of seabirds in California during 2005-2010, using data on: (1) live oiled birds reported to the Oiled Wildlife Care Network (OWCN) from throughout the state, and (2) dead oiled birds found during systematic monthly beached-bird surveys in central California. A mean of 245 (±141 SD) live miscellaneous oiled birds (not associated with known oil spills) were reported to the OWCN per year, and 0.1 oiled dead birds km−1 per month were found on beach surveys in central California. Chemical fingerprinting of oiled feathers from a subset of these birds (n = 101) indicated that 89% of samples tested were likely from natural petroleum seeps off southern and central California. There was a pronounced peak during late winter in the number of oiled birds reported in southern California, which we theorize may be related to large storm waves disturbing underwater seeps.