Artificial Seaweed Stems Erosion at Beach : Controversial Experiment Is Apparently Paying Off in Long Beach

For 30 years Barbara Poppler has lived in her shingle house by the sea. And for 30 years, from her living room window, she has watched the beach shrink and grow and shrink again.

Mostly it shrank. The waves washed away the beach, no matter how many times dredging boats picked up sand from the ocean floor and spewed it back to the shoreline--and despite the jetties and the offshore breakwater designed to prevent erosion.

On occasion, Poppler has had to climb a ladder from her front porch onto a beach that was merely a narrow sand spit 15 feet below. Just two years ago, the neighbors helped pile sandbags at the ends of the streets, trying to hold back the Pacific.

The Beach Is Back

But those days may be gone for good. The beach is back, and Poppler’s windows now frame a view of sunbathers relaxing on a wide expanse of sand where the waves once broke.

Long Beach officials give most of the credit to artificial seaweed, an unusual--and controversial--experiment in erosion control. Long Beach is the first city on the West Coast to “plant” the seaweed, in this case 1,500 plastic devices that mimic the waving action of seaweed.

However, both the U.S. Army Corps of Engineers and the state of California have declined to use the “seaweed” because its effectiveness has not been conclusively proved.

But in Long Beach, city officials were desperate.

Efforts to hold a 2,100-foot section of shoreline on the east end of town had failed repeatedly. The city was spending $100,000 to $150,000 a year for emergency beach protection, and the pressure from worried homeowners was mounting.

Now, 15 months after the seaweed was installed, Long Beach officials are proclaiming their $60,000 experiment a success. And inquiries about the innovative technique have poured in from as far away as Florida, Hawaii, North Carolina and Australia--and from Carlsbad, a town of 40,000 in northern San Diego County.

‘Legitimate Tool’

“It is not a panacea,” said Public Works Director James Pott. “But I’m through monitoring this thing now. I’m satisfied that it is a legitimate beach erosion management tool.”

Each piece of the fake seaweed consists of several 4-foot-long, finger-like fronds of plastic, anchored at the bottom by tubes filled with sand or polystyrene. Some of the fronds are equipped with round, white flotation devices that look like miniature Ping-Pong balls.

The theory behind the artificial seaweed is simple: The anchor keeps it in place on the ocean floor while the fronds float up and wave gently, calming the currents under the surface and allowing sand suspended in the water to drop down. Instead of being carried far out to sea, the sand piles up at the shore. The seaweed does not create a new beach; it keeps the existing sand in place.

In April, 1983, after the city spent $840,000 to widen the beach, the seaweed was placed several hundred feet offshore of the troublesome section--2,100 feet of East Beach, on the seaward side of the peninsula adjacent to Orange County. The site runs roughly from 56th Place to 72nd Place south of Ocean Boulevard, where Poppler and about 200 other families live.

East Beach has historically eroded faster than the rest of the local shoreline, partly because it is east of the federal breakwater that protects other parts of the Long Beach coast.

Plea for More

Pott says East Beach has not lost a discernible amount of sand since the last replenishment. He is recommending that the city spend another $50,000 to plant more artificial seaweed there.

“If it’s done again, the beach will recede at still slower rates,” Pott said. “If we can reduce the need to replenish the beach to once in a blue moon, we will have a fairly stable beach.”

That would be a first. Since World War II, the city had tried 200-foot-long timber groins to hold the sand and relied unsuccessfully on a U.S. breakwater about three miles offshore to sap the strength of the ocean waves.

For 30 years, the beach was periodically replenished with sand from the harbor or Alamitos Bay. Teen-agers who grew up on East Beach remember the dredges depositing sand on the shore regularly, interrupting their use of the beach.

“It was a never-ending battle until recently,” said Karl Zittel, a 17-year-old who has grown up in the area.

Erosion Rate

City records describe an average erosion rate on East Beach of 5 to 10 feet each year from 1957 to 1978. Within that period, it dropped to 2 to 7 feet per year from 1974 to 1976 and then rose to 40 to 50 feet each year from 1976 to 1978, periods in which the city experienced severe storms. The dredges just couldn’t keep up.

Clamoring for Relief

By 1979, residents were clamoring for relief. “We were throwing literally hundreds of thousands of dollars on the beach and we couldn’t keep the sand there,” said City Council member Jan Hall, whose 3rd District includes East Beach.

“We needed something that was technically workable but also acceptable in the community,” Hall said.

East Beach residents opposed seawalls that would protect homes but concede the loss of the beach for recreational activities; and they opposed building more jetties that would not ensure the degree of protection they sought. Building another breakwater would cost about $2 million--$1 million more than was available.

The city decided to try placing “bird’s eye” sand--actually tiny gravel--on the beach after a consultant said its weight would keep it from being easily washed away. The consultant recommended placing the “bird’s eye” at the ocean’s edge to form a dike.

‘Pebble Beach’

The project was nicknamed “Pebble Beach” and the gravel was installed in the fall of 1980. But during the severe winter of 1980-81, storms breached the dike. Beach maintenance crews later mixed the “bird’s eye” with the other sand.

At this point, Public Works Director Pott heard about the seaweed theory. Planting real seaweed was out of the question--”it grows on a rocky bottom and we have a sandy bottom,” he said.

He investigated the use of artificial seaweed at Cape Hatteras, N.C., and along Lake Michigan in Illinois. Officials in those areas reported that sand loss had slowed but weren’t sure if the “seaweed” deserved full credit.

Pott was leery but considered giving it a try. Hall agreed to test constituents’ reactions. She went to meetings at residents’ homes, bringing a sample of the artificial seaweed.

At Least Safe

“I called it a hula skirt; I’d hold it up and show them my hula skirt,” Hall recalled. “We all decided that it was at least safe. If it didn’t work, at least it wouldn’t hurt the environment when we tried it.”

Response was favorable. “We had to give Jim Pott credit” for trying something new, said Don Utter, past president of a homeowners’ group in the East Beach area. “He took an awful lot of flak about the ‘bird’s eye’ on the beach and he was willing to take another gamble.”

Elsewhere, beach erosion experts have not been as ready to gamble.

For example, the state recently refused a request from the Carlsbad City Council for $150,000 for an artificial seaweed program there. Consequently, a matching allocation from the council has been delayed, said Carlsbad City Manager Frank Aleshire.

Unwilling to Risk It

“Everybody knows it’s still an experiment and the state was unwilling to take the risk,” Aleshire said.

The U.S. Army Corps of Engineers has not endorsed the seaweed technique, either.

“I personally don’t think that that beach grass will maintain the sand,” said Donald G. Spencer, chief of the corps’ shore protection section in Los Angeles.

“Normally we consider harder structures for beach erosion control on the Pacific. We have a very severe wave environment on the open Pacific Coast.”

He also noted that because of the mild winter, the hold of the seaweed on East Beach sand has yet to be tested by a severe storm.

Pott is well aware of that. “I don’t care,” he said. “We know what we’ve seen.” Divers checking the seaweed last month had to dig through four feet of sand that had piled up to find the plastic “plants.” So Pott is convinced that even if a storm washes the sand away, the artificial seaweed will trap it again, slowly rebuilding the beach.

“It heals itself,” he said.

Once-frustrated East Beach residents seem to be converts too. Said Poppler: “I haven’t been swimming yet this year, but my friends say the beach has a real good slope to it under the water. Usually, we have some potholes out there where the sand’s been washing away.

“When they were putting that stuff out there, I thought, ‘Another dumb idea,’ ” she added. “But it worked.”