|
By
David Reyes
Los
Angeles Times
September 13, 2006
The recent restoration of the Bolsa Chica wetlands may be
killing off a grove of eucalyptus trees that appears to be
under attack by seawater that has been allowed to flow back
into a far corner of the marshlands.
The stand of trees is in the northern lowlands of Bolsa Chica,
where ocean water from nearby Huntington Harbour has been
permitted to pour back in but isn't properly flowing back out
with the tide.
The seepage of seawater is apparently unrelated to — and
physically separated from — the inlet recently cut from the
ocean to the wetlands that replenished a huge portion of the
marshlands with salt water for the first time in more than 100
years.
Dozens of eucalyptus, which were healthy several months ago,
are now dead or dying in and near the Bolsa Pocket, a 42-acre
area in the northeast corner of the wetlands.
Environmental activist Mark Bixby said he first noted the
problem in early summer after restoration officials let ocean
water back into the Pocket.
"It was supposed to be a 'muted tidal area,' " Bixby
said. "But now it's a stagnant pond. There's water in
there all the time."
He said he hoped federal restoration officials would install
an underground barrier for the Pocket to protect other trees.
Such an effort was undertaken to protect other areas near the
Wintersburg Channel, which runs alongside the wetlands.
Biologists hired by Hearthside Homes, which is building more
than 350 bluff-top homes on the mesa above Bolsa Chica, agree
that seawater intrusion is probably the cause of the tree
deaths, said Ed Mountford, a Hearthside vice president.
"This doesn't affect us because it's not on our
property," Mountford said. "It's state property
below ours, and when we were made aware of the situation, we
wanted to make sure that the seawater doesn't migrate
underground too far."
Federal officials don't deny that more water than expected has
filled the Pocket. But they add that there is no "solid
evidence" that points to the restoration work as the
cause of the dead and dying trees.
In the affected area, the soggy soil has caused trees to lean
over and die as their roots are exposed. Their leaves are
brown instead of their natural green hue, Bixby said.
"There is some accuracy with [the assertion of] the
Pocket not performing as expected," said Robert Hoffman,
a National Marine Fisheries Service biologist who is on the
restoration project's steering committee. "But there were
dead trees in that area before the restoration. We would have
to look at photographs, before and after," to make an
assessment. "Those trees were stressed before our project
started."
The groundwater level in the wetlands is high to begin with,
Hoffman said.
Homes that back up to the main wetlands have had backyards
flooded during winter storms, which prompted federal
restoration officials to install a protective water barrier 30
feet deep in some areas, Hoffman said.
"Our charge was not to worsen the groundwater
situation," he said. "There's water moving out from
inland and water moving in from the ocean in that area. There
was, during preparation, a legitimate concern about
this."
Hoffman said he had not visited the eucalyptus grove. But he
said restoration officials intended to assess the area and
"fix it up," which means digging and removing
sediment that is blocking the water from flowing back out of
the Pocket.
In addition, they can adjust the flow of ocean water with tide
gates near Warner Avenue, Hoffman said. "It's tough to
get things to work exactly right the first time," he
said. "Things don't always work exactly to plan."
Bixby says that may not be enough. He said the eucalyptus
stand also serves as habitat for birds such as the
white-tailed kites and the endangered California gnatcatcher.
"I wonder what environmental agencies and others would
think when they hear that a decision made by federal officials
may have destroyed the habitat for sensitive species," he
said.
The recent restoration efforts capped a three-year,
$147-million state project to reclaim a portion of the
880-acre wetlands that, for years, had been used for oil
drilling.
Once slated to be developed into an oceanfront housing tract,
the wetlands were spared by environmentalists who lobbied for
both money and political support to restore the marshland.
Although fresh water — mostly urban runoff carried in flood
channels — has long drained into the marshland, ocean water
had, until Aug. 24, been blocked from reaching the area.
It was the most significant and visible step in the long,
ambitious effort to revive the degraded wetlands.
The flow of ocean water — cut off by members of a duck
hunting club in 1899 — is expected to help transform the
saltwater marshes into a major wildlife sanctuary.
*
|
