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LOS ANGELES — Overfishing of the world’s seas may be causing a ripple effect that can devastate the ecosystems on which future catches depend, according to a study released Monday. 

“The overwhelming weight of evidence from available fishing data points to the severe, dramatic and sometimes irreversible consequences of fishing on marine ecosystems,” said the report released at an oceans conference in Santa Barbara. 

The report calls on the United States to protect ecosystems by comprehensively zoning waters for industrial, commercial fishing or recreational uses rather than making piecemeal closures of certain fishing grounds. 

The report comes on the heels of last week’s decision by the California Fish and Game Commission to declare 130 square miles of ocean around the Channel Islands off-limits to fishing, beginning next year. The ban aims to protect individual marine species by preserving their entire ecosystem. 

In the past, state officials had attempted to do that by setting size or catch limits or enacting seasonal closures. 

The report for the Pew Oceans Commission took a comprehensive look at other studies of fishing. Worldwide, 25 percent to 30 percent of all fish stocks currently being caught are being overfished to some degree and another 40 percent is at risk of soon being overexploited, the report said, citing a 1999 study. 

A report to Congress last year from the National Marine Fisheries Service found that about one-third of the 304 U.S. fishing stocks for which the status was known were being overfished, the study. 

“Even populations that show no immediate impact from being fished may (through their loss) cause disproportionate declines in abundance of species that forage upon them,” the report said. 

Global overfishing is masked somewhat because new technology allows fishermen to go after previously unreachable fish and because, as one species declines, commercial fishers turn to other ones lower down on the food chain, the report said. 

Current fishing procedures also destroy important habitat where fish breed and grow up, such as corals, seagrasses and sponge beds, the study said. 

In addition, fishing can decimate populations of seabirds, turtles, sharks and other species that are caught inadvertently. 

“For centuries, we have viewed the oceans as an infinite resource beyond our capacity to harm. We now know that this is not true,” Leon Panetta, chairman of the Pew Oceans Commission, said in a statement. 

The study concluded that the United States needs to overhaul its fishing laws, which it called cumbersome and unenforceable, to concentrate on protecting ecosystems rather than single species.