Divers work to save dwindling kelp fields

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Posted by on June 10, 2005 at 22:14:57:

MALIBU – At 35 feet down in Santa Monica Bay, there's enough visibility on one gray, overcast morning for Tom Ford to actually see what he is doing.

He's showing volunteer diver Sandy Stewart the proper way to survey substrate – the ocean bottom's pebbles, boulders, reef and sand – essentially looking for anything rocky enough on the ocean floor to play host to kelp.

As the scuba divers make their way across the ocean floor, they encounter a few members of the red, white and purple menace.

Urchins, that is. And if you're a giant kelp, they are a menace.

Near where Ford and Stewart are diving, giant kelp reaches up and makes a gentle 90-degree turn along the surface to form a shadowy canopy of root beer-brown stalks and blades.

In all that massive reach of algae, there's one part the bottom-dwelling urchin seems to be interested in: the kelp's holdfast, right at the base. A surfeit of hungry urchins, nibbling away at the crucial holdfasts, can lay waste to a kelp forest.

But within the complex tangle of ecosystem and habitat, the spiny urchin – purple, red or white – can't take the blame for the decimation of the coastal kelp forests.

"It's kind of like the deer devouring the forest once the wolves are gone," Ford said. "The urchin didn't get the memo that it was supposed to stop reproducing."

And not only are the urchins' predators vanishing, but climate changes that alter water temperature also affect kelp, as do storms that can rip the strands right off the rocks. In recent years kelp forests off the largely pristine Channel Islands have rebounded from damage in the 1990s compared with mainland kelp, suggesting that coastal development and urban runoff play a major role in suppressing kelp growth.

Some people want to give kelp a chance.

So biologists like Ford and volunteers like Stewart are working as part of an ongoing project to restore kelp forests from Santa Barbara to San Diego, and thus open the door to the rich diversity of fish and invertebrates that populate kelp habitat.

Overseen by the California Coastkeeper Alliance, the project is currently funded by a three-year, $600,000-plus grant from the National Oceanic and Atmospheric Administration and another $600,000 from the California Coastal Conservancy.

Ford, whose wet suit is emblazoned with a green capital "K" for Captain Kelp, is a marine biologist for the Santa Monica BayKeeper. Among other things, he manages the replanting of kelp beds off Malibu and the Palos Verdes Peninsula – the Los Angeles County portions of the restoration project.

For the regional project, the Coastkeeper Alliance operates a lab on Terminal Island that is a kind of in vitro fertilization center for giant kelp. Spore-bearing blades are brought there and induced to emit those spores, which are nurtured into growths that can be transplanted to one of the restoration sites along the coast.

Ford has tried growing the lab-bred transplants at his Malibu site near Escondido beach, but didn't have much success. However, last year, when the transplants didn't flourish, he tried a different method of seeding the potential kelp beds.

Divers replanted by taking pod blades, putting them in mesh dive bags and anchoring the bags in prime spots on the ocean floor, allowing them to distribute spores.

But before any of that could take place, Ford and his volunteers had to remove and relocate 17,000 urchins.

"When we first got out here in 2003, we couldn't even see the rocks."

Usually there aren't that many urchins, and the substrate can be surveyed without having to pluck off all the spiny creatures first. Eventually, the urchins must be relocated, and the young kelp is moved in, or seeding bags are placed.

A new stand of kelp about 200 yards long floats off Malibu thanks to the placing of seed bags about a year ago. Kelp can grow several feet a month if it gets the light and nutrients it needs, and if the urchins don't prey upon it.

Kelp stands suffered in the '90s with El Niño's warm water, canopy-ripping storms and a flourishing of urchins.

About 80 percent of the historical kelp forest off Southern California has disappeared, according to California Coastkeeper.

One of the urchin's most able predators is the sea otter, but under wildlife management agreements, the animal is not permitted to stay in Southern California waters. Sheephead fish and lobsters eat urchins, but to become adept at consuming urchins, they need to be big, and the biggest sheephead and lobster have been fished out, Ford said.

There is another predator. California commercial divers landed more than 11 million pounds of red urchins in 2003, mostly for export to Japan. The urchin eggs are sold at home and abroad in markets and restaurants as "uni."

Commercial divers mostly go after the red urchins because they are generally larger and thus more desirable in the marketplace, said Peter Halmay, president of the Sea Urchins Harvesters' Association. But Halmay believes it may be possible to develop a fishery for purple urchins as well.

"Having good kelp is a necessary part to the urchin fishery. Growing kelp is a good idea," Halmay said.

Development of the red urchin fishery in the 1970s and '80s is credited with expanding kelp beds, Ford said, so it's possible that a thriving purple urchin market could have the same effect.

As long as they aren't too numerous, urchins are an important part of the kelp habitat. Ford said that small fishes, shrimp, juvenile urchins and abalone hide in the urchin's spines for protection.

At the Terminal Island lab housed at the Southern California Marine Institute, a layer of reddish-brown slime coats piano key-size pieces of unglazed tile.

Project coordinator Dirk Burcham tends the long, narrow trays of seawater kept under fluorescent grow lights.

In addition to helping to nurture the buds that will be taken out to several sites in the ocean from San Diego to Santa Barbara, Burcham also oversees the educational and public outreach of the restoration project, which includes sending representatives to classrooms to teach about kelp, and maybe even take around a few "eco-cart" aquariums, units where kelp can be grown in the classroom.

In the ocean, kelp prefers a rocky or hard ocean floor, although it will grow in certain soft-bottom areas. When there's kelp, there's more life, more for divers to see.

"A kelp forest is infinitely more interesting, that's why a lot of people like it. There's more fish, that's why fishermen like it," he said.

California is one of the few places in the world where giant kelp grows.

Off the Palos Verdes Peninsula's Long Point and Point Vicente, the survey dives have recently begun, in depths of 35 to 50 feet, not far from shore. In these preliminary expeditions, Ford and his volunteers found some of the rocky bottom not only devoid of kelp, but devoid of fish, too.

The kelp restoration project hopes to change that situation up and down the coast, in an era when fish stocks have been plummeting.

"Our success would be when the kelp comes back and all the fish as well," Ford said. "We're trying to make it so the community comes together."

In the year-old kelp forest off Escondido in Malibu, there's evidence of that, with sand bass, kelp bass and striped sea perch swimming through the stands where invertebrates like Kellet's whelks and sea cucumbers dwell.

For biologist and volunteers, that's the kind of scenery that makes the long boat ride and a swim in 55-degree water all worth it.

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