Posted by --! on October 14, 2005 at 09:37:17:|
Sea farmers struggle to save kelp from predatory urchins By Sara Lin Tribune
Not many farmers wear wet suits to work. But Tom Ford isn't running your average ranch. Instead of a tractor, he drives a motorboat. And rather than chase away insects and rodents, he fights off prickly sea urchins. Ford's one acre lies below 32 feet of murky water off of Malibu--one of several patches off the Southern California coast where biologists from Santa Barbara to San Diego are determined to recarpet 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 percent of Southern California's once-flourishing kelp beds has vanished.
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 depleted fish population will shrink further.
`We should protect it'
"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
Since the 1960s, scientists, including academics and those from government agencies and non-profit groups, have tried to restore the kelp.
Even after El Nino storms ripped the plants out, divers kept coming back with 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 protect them from being eaten.
None of their efforts amounted to much: Only two 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 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, supports nearly 800 species ranging from sea squirts to 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 at lower temperatures. California and Alaska are the only two places in the Northern Hemisphere where giant kelp grows.
Scientists say humans also are to blame for kelp's demise because they pollute the ocean and overfish the urchins' natural predators--lobsters, sheep-head fish and sea otters.
More than 85 percent of seedlings planted are gobbled up by urchins or fish before they can mature.
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 underwater.
"Yes, it's labor-intensive, but you've also got kids learning about kelp and how important kelp is," said Natalie Cosentino-Manning, a marine ecologist with the National Oceanic and Atmospheric Administration.
Despite the challenges, Ford, the Malibu kelp farmer and director of kelp-restoration efforts for the environmental group Santa Monica Baykeeper, remains undeterred--and hopeful that he can restore 10 acres a year.
Man vs. urchin
When eight adult plants took hold three years ago off Point Dume, Ford saw his chance to tilt the scales in nature's favor.
Armed with a rake and mesh satchels, he and volunteers purged the area of purple, red and white urchins--bagging 25,000 last year alone.
The urchins--they can crawl several yards a day using hundreds of tiny sucker-like tube feet--have denuded other areas to the point that Ford swears he has seen them resort to cannibalism.
When they find a kelp bed, they feast on it like rabbits in a vegetable garden, he said. At his Malibu site, Ford recalled, there were so many urchins that "you couldn't even see the bottom. ... They were everywhere."
As added insurance, Ford dropped 5-foot-tall mesh bags loaded with kelp leaves that would release millions of spores into the water.
The eight kelp plants have multiplied into an acre.
It might not last, but Ford wants to bring back natural balance between urchins, fish and kelp, hopefully setting the stage for kelp to bounce back quicker after a devastating storm.
"A few of my detractors would say, `Forget it, man, you'll burn out on this,'" Ford said. "But if the kelp goes away, a great deal of what is our marine heritage will be gone."
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