The oil production technique known as fracking is more widespread and frequently used in the offshore platforms and man-made islands near some of California's most populous and famous coastal communities than state officials believed. In waters off Long Beach, Seal Beach and Huntington Beach - some of the region's most popular surfing strands and tourist attractions - oil companies have used fracking at least 203 times at six sites in the past two decades, according to interviews and drilling records obtained by The Associated Press through a public records request. Offshore hydraulic fracturing ... occurs with little state or federal oversight of the operations. The state oil permitting agency said it doesn't track fracking. Environmental groups are calling for a moratorium on the practice. How is it that nobody in state government knew anything about this? It's a huge institutional failure," said Kassie Siegel, an attorney with the Center for Biological Diversity. "Offshore fracking is far more common than anyone realized." Little is known about the effects on the marine environment of fracking, which shoots water, sand and chemicals at high pressure to clear old wells or crack rock formations to free oil. Yet neither state nor federal environmental regulators have had any role in overseeing the practice as it increased to revitalize old wells. New oil leases off the state's shores have been prohibited since a 1969 oil platform blowout off Santa Barbara, which fouled miles of coastline and gave rise to the modern environmental movement. With no room for physical expansion, oil companies instead have turned to fracking to keep the oil flowing.