Monday, August 30, 2010

Kelp Restoration Works - Implications for Blue Carbon

IUCN's report titled 'The Management of Natural Coastal Carbon Sinks' cites kelp's potential for climate mitigation. Good news, kelp restoration works! 

(Good news also for all the kelp forest critters and associated fisheries)

Massive artificial reef grows like wild

By Mike Lee (, August 18, 2010.

Large beds of giant brown kelp are thriving in the artificial reef built off the coast of San Clemente north of the San Onofre Nuclear Generating Station.

A major initiative to boost sea life appears to be paying off in the coastal waters near San Clemente, where power companies spent $46 million to build what is touted as the nation’s largest artificial reef.

Large beds of giant brown kelp are thriving in the artificial reef built off the coast of San Clemente north of the San Onofre Nuclear Generating Station.

Large beds of giant brown kelp are thriving in the artificial reef built off the coast of San Clemente north of the San Onofre Nuclear Generating Station (image credit Eduardo Contreras).

Independent monitoring by scientists at the University of California Santa Barbara shows that the reef reached nine of 14 benchmarks during its first year of operations. Power company officials said Wednesday they are poised to meet the other standards, perhaps this year.

The Wheeler North Reef is part of a piecemeal strategy by ocean advocates for using artificial reefs to boost habitat for marine creatures, improve fishing and provide more opportunities for divers. It was required by the California Coastal Commission to make up for the ecological damage done by the San Onofre Nuclear Generating Station in North County, which is owned by Southern California Edison, San Diego Gas & Electric Co. and Riverside.

On Wednesday, Edison showed off the giant kelp forest that has grown over the past several months and highlighted the first UCSB monitoring report. Kelp forests sometimes are called the “rain forests of the sea” because they support hundreds of species of marine life.

“We are really well on the way to having duplicated a very complex ecosystem on a large scale,” said David Kay, head of environmental projects for the company. “You look offshore and you see this massive area of kelp canopy floating on the surface. … This is an amazing accomplishment.”

As he talked, the 174-acre reef spread out below a company helicopter for about two miles south of the San Clemente pier.

From the air, it’s obvious where Edison placed boulders at depths of about 30 feet because wavy tendrils of brown kelp — anchored to the rocks below — carpet the ocean’s surface like giant strands of hair. A few fishing boats bobbed in the gentle swells at the edge of the shimmering marine forest while seabirds rested and fed on the matted kelp.

Before the artificial reef was constructed, “Nothing was there,” Kay said. “You don’t have to be a scientist to say kelp density turned out pretty good.”

Ecologist Stephen Schroeter of UCSB’s Marine Science Institute was more reserved, but his assessment was upbeat.

“They have done a really nice job,” said Schroeter, part of the reef monitoring team that regularly dives at the site. “It looks like it’s on a hopeful trajectory.”

He said some of the unmet benchmarks may prove challenging, particularly one that sets the amount of fish in the reef by weight. The goal is 28 tons; only 16 tons were observed in the first year.

Despite the positive trendline, Schroeter urged caution about the widespread use of a similar approach.

“There may in fact be other places where artificial reefs may be a very useful mitigation measure, and we are learning important lessons about how you might want to go about doing that,” he said. “But I don’t think it’s a recipe for making kelp up and down the coast.”

The roots of the Wheeler North Reef go back to 1974 when the California Coastal Commission issued a development permit for units 2 and 3 of the nuclear plant. Years of monitoring led to new permit conditions to make up for ecological harm done by the plant.

They include restoration of the San Dieguito marsh, financing of a marine fish hatchery and construction of an artificial reef to replace kelp beds harmed by the plant.

The reactors are cooled by a system that each day takes in the volume of seawater equal to one square mile 14 feet deep, according to a UCSB analysis. The water is heated by the plant and released through pipes in the ocean. The discharge plume has redistributed sediment, decreasing the amount of light that reaches the kelp growing directly offshore of the plant.

UCSB researchers said cloudy water offshore caused a substantial reduction in the kelp forest, resulting in losses of fish and invertebrates.

The new reef is north of the nuclear plant near San Clemente. It started in 1999 as a 22.4-acre experimental project designed to guide construction of a larger reef.

“We don’t want to have to go back and redo things,” said Kay at Edison.

The rocks, quarried at Catalina Island, are roughly the size of medicine balls and scattered in a single layer on the sand, not piled on top of each other.

Kay said the goal was to create a dynamic ecosystem in which the boulders are jostled during storms so they can clear out patches of old-growth kelp and create a natural mosaic.

“To get giant kelp coming back generation after generation, there always needs to be bare rock on the reef, and you are only going to get that if you have an unstable reef,” he said.

So far, the rocks have performed as Kay hoped. The first of UCSB’s annual reports said the rocks were not sinking into the sand — a possible threat to the reef. It also said that fish abundance and diversity at Wheeler North was similar to or greater than natural reefs nearby. The study team didn’t find evidence of invasive species harming the reef.

“Generally, things are going well,” said Susan Hansch, chief deputy director at the Coastal Commission. “The kelp is flourishing.”

She warned that Edison is not in the clear yet. “They are going to be monitoring and responsible for these mitigation sites for a long time,” she said.

Kay is hopeful that the reef will meet all its performance targets this year without additional intervention by Edison. The company is responsible for the reef for at least 40 years, though Kay expects it to last for centuries.

“It goes on its own at this point,” he said. “We are just watching it grow.”


California Coastkeeper Alliance - Restoring Southern California’s Kelp Beds 

Santa Monica Baykeeper - Kelp Restoration Project