According to the San Francisco Examiner, dredge mining of shoals near Angel and Alcatraz islands and throughout Suisun Bay is robbing the bay of sand that keeps San Francisco's Ocean Beach from eroding.
Partly as a result of sand mining, the 10-mile stretch between southern Ocean Beach and Point San Pedro near Pacifica is eroding faster than any other section of coastline in California, according to the U.S. Geological Survey. The findings are based on models of tidal currents and sediment flow showing that some of the sand that erodes from the Sierra and eventually passes through the Golden Gate is deposited on coastal beaches.
In October, the California State Lands Commission granted a dozen 10-year sand-dredging leases – nine in the central bay and three in Suisun Bay – to two companies, Hanson Marine Operations of Pleasanton and Jerico Products of Petaluma. A nonprofit environmental group, San Francisco Baykeeper, countered with a lawsuit in November, claiming that the project's environmental impact report didn't properly assess the effects of mining activity on coastal erosion.