Such a project, peninsula resident Linda McCullough said, "would be an experiment, because no one knows what's going to happen."
Even some sea life could be displaced. Waters inside the breakwater now serve as a nursery for young fish, mimicking the function of long-gone coastal wetlands, said Robert J. Hoffman, an expert at the National Marine Fisheries Service. Full surf could mean more habitat for mature fish, but less for their young.
Wave scientists say there is little precedent to suggest how the surf would change without the Long Beach breakwater.
"I've heard of dams coming down. I've never heard of a breakwater," said coastal oceanographer Reinhard Flick, who studies waves and beaches at the Scripps Institution of Oceanography, part of UC San Diego.
The beaches would change shape as waves shifted the sands, experts said.
Water quality would probably improve because the breakwater would no longer force dirty water from the mouth of the Los Angeles River back against the coast, and the waves would scour and clean the beaches, said civil engineer Hendrik Tolman, who does wave predictions at the National Oceanic and Atmospheric Administration. Sea foam created when the waves break can increase the water's oxygen content, further cleaning it, he said.