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Efforts to Restore Kelp Suffering Growing Pains

Sea urchins and El Nino are factors. But scientists press on to repopulate a critical marine habitat.

October 03, 2005|Sara Lin | Times Staff Writer

Not many farmers wear a wetsuit to work. But Tom Ford isn't running your average farm. Instead of a tractor he drives a motorboat. And rather than chase away insects and rodents, he fights off prickly sea urchins.

Ford's 1 acre lies below 32 feet of murky water off Malibu -- one of several patches off the Southern California coast where biologists from Santa Barbara to San Diego are determined to re-carpet the ocean floor with giant kelp, a leafy, golden-brown seaweed that has largely disappeared from the region.

But for all the millions in private and public funds spent since the 1960s, experts say, the effort may be in vain. Over the last half-century, nearly 75% of Southern California's once-flourishing kelp beds have vanished, particularly off Los Angeles and Orange counties.

Like coral reefs and tropical rain forests, kelp is a critical habitat, its floating canopies providing shelter and foraging grounds for marine life. Without it, biologists say, Southern California's already depleted fish population will shrink even further.

"If you go into a kelp forest, the place is swarming with fish," said Paul Dayton, a marine ecology professor at Scripps Institution of Oceanography. "Take out that kelp and the fish won't go extinct, but they'll be much rarer because they don't have the habitat.... We should protect it just on the grounds that it's for our grandchildren."

Since the 1960s, scientists -- including academics and those from government agencies and nonprofit groups -- have tried to restore the kelp.

Even after El Nino storms ripped the plants out, divers kept coming back with tens of thousands of seedlings. When that didn't work, they scattered spores. They even tried warding off marauding urchins and fish by draping giant nets over baby kelp beds to try to protect them from being eaten.

None of their efforts amounted to much: Only 2 acres of kelp were restored in Southern California from 2001 to 2004, say environmental groups that spent $2.5 million in state and federal grants.

"Little programs to help plant a little kelp here and there is like putting a finger in a hole in a dike to hold back water," said Scripps ecologist Ed Parnell. "How much effect can a few divers replanting a few kelp plants here and there [have] in the face of El Nino?"

Kelp, algae that can grow in depths of 30 to 80 feet and to even greater lengths, is the second-most diverse marine community, supporting nearly 800 species ranging from sea squirts to sheephead fish and sea scallops. Even gulls and sand crabs reap benefits when tangled clusters of kelp wash ashore.

Harvested worldwide, kelp can be found in paper, beer and cosmetics. The kelp byproduct algin, for example, prevents ice crystals from forming inside ice cream and keeps the foamy top on beer from dissolving.

But in the last 50 years, frequent episodes of warm-water El Nino have devastated kelp, which thrives in colder temperatures. California and Alaska are the only two places in the Northern Hemisphere where giant kelp grows.

Scientists say humans are also to blame for kelp's demise by polluting the ocean and overfishing the urchins' natural predators -- lobsters, sheephead fish and sea otters. Vast stretches of ocean bottom have become "urchin barrens," where 3- to 5-inch urchins litter the landscape.

But replanting the rocky seafloor with kelp isn't easy. More than 85% of seedlings planted are gobbled up by urchins or fish before they can mature.

Kelp diver Mike Curtis should know. In 1988, he planted 700 inch-tall seedlings off Crystal Cove State Park between Newport Beach and Laguna Beach. Within a week, every seedling except two was eaten -- one was probably spared because it was in a hard-to-reach crevice.

Curtis kept at it every week, bringing down seedlings grown on ceramic tiles meant to simulate rock. After a year, when a decent kelp bed had taken root, he moved on. He returned two years later only to discover a barren seafloor.

"Ours just went belly up," said Curtis, a senior scientist with MBC Applied Environmental Sciences, a Costa Mesa firm that often does kelp restoration for developers. "The best you can do ... is bring some more spores into the area and hope ... that natural cycles come in and do the rest."

With no underwater scarecrow to keep fish and urchins away, a colleague, ecologist Chuck Mitchell, tried to fix the problem by fencing off his kelp beds with giant fish nets.

But fish died in the netting, attracting hungry crabs that crawled in to eat the dead fish. The net also became a magnet for floating debris.

"It was a maintenance nightmare," Mitchell recalled. "You can expend huge amounts of money trying to bring kelp back to an area without doing much good."

Despite kelp restoration's mixed results, federal scientists put stock in the project's educational success. Thousands of schoolchildren learn about kelp as they help grow seedlings in the classroom that are later put down underwater.

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