On any given morning, bird watchers and plein-air artists admire the Upper Newport Bay and its avian denizens. Joggers and cyclists pause to take it all in, and kayakers paddle through the shallow water. Aside from the occasional passing airplane, the trill of birds dominates the soundscape.
But something is wrong.
Silt-laden urban runoff from San Diego Creek has clogged the bay, forming mudflats that choke out the tides. Islands created during previous dredgings as nesting areas for endangered birds are becoming peninsulas instead, providing a highway for predators, including coyotes, foxes and others.
The estuary is on the verge of becoming a meadow.
Now, after years of urging from naturalists who flock to the state ecological reserve -- which biologists consider one of California's environmental gems -- the bay will get a much-needed dredging. Earlier this week, Orange County supervisors signed off on a $38-million dredging project to prevent the mud-choked bay from turning into grasslands.
"We're very pleased this is finally happening," said Jack Keating, a founding member of the Newport Bay Naturalists & Friends. "We have to have the dredging to allow it to function as an estuary."
The 752-acre reserve is one of the largest in Southern California and is considered among the finest bird-watching sites in North America. During the winter migration season, as many as 35,000 birds visit the bay at any one time.
The Irvine Co. had plans to develop the bay into a marina, but Newport Beach residents Frank and Frances Robinson led an effort, beginning in the 1960s, to preserve the estuary. After a drawn-out court battle, the state purchased Upper Newport Bay and designated it a wildlife sanctuary in 1975.
The bay is home to at least six rare or endangered species: the light-footed clapper rail, brown pelican, Belding's savannah sparrow, the black rail, the peregrine falcon and the California least tern.
Dredging is crucial to the health of the estuary, said Dennis Kelly, a professor of marine science at Orange Coast College in Costa Mesa.
"Mudflats are a great thing, but the trouble is, we're talking about mudflats that are silted to the point that they're not really mudflats anymore," he said. "They're beginning to grow plants, and so now you basically have a roadway out to the islands."
The bay, which is connected to Newport Harbor, was at a tipping point, Kelly said. "If it were to go on like this for another year, you'd start losing birds," he said.
Because the bay is shallow and wide, the runoff carried down San Diego Creek slows as it washes into the estuary. The dirt and debris from inland cities settles in the upper bay.
Each year, more sediment flows into the bay than is flushed out by the tide, leading to a build-up of the mudflats. Last winter's unusually heavy rains exacerbated the problem.
For those who regularly venture into the bay, the results are easy to see.
Steering a small pontoon boat into the Upper Newport Bay on a sunny Friday afternoon, Billy Whitford, of the Newport Aquatic Center, keeps his craft centered in the narrow waterway. Even at high tide, brown mudflats are inches beneath the green water. Birds perched on the mud look like they're standing on water.
"At low tide, there's just a little ribbon of water," he says. "If you don't know where you're going in here, you'll get stuck."
As the boat glides deeper into the estuary, red-beaked, black and white birds called skimmers fly low over the water, hunting for fish. Mullet leap out of the water in graceful arcs, while a flock of tiny sandpipers fliesby, turning and showing their white bellies. Waist-high patches of grass sprout from the shallow water -- the first sign that a meadow is forming.
"[The estuary is] pretty magnificent to think about, but boy if they don't do something, we're sunk," Whitford said. "It'll just fill in and become pastureland."
The dredging will be done by the U.S. Army Corps of Engineers, which will share the cost. The project will likely begin in early fall and continue for two years.
The bay has been dredged at least twice before, in the 1980s and in 1998. County officials have planned the current dredging for five years, but federal funds became available only this year.
An estimated 2.1 million cubic yards of sediment will be dumped at sea, and an island set aside for the least terns will be relocated closer to the harbor's lower basin. Known to bird watchers as Skimmer Island, it is the larger of the bay's two sand patches -- the other is known as Tern Island. Skimmer Island must be relocated to make way for deepening of a sediment basin off Jamboree Road.
Plans also include restoration of wetlands and mudflat habitat along Northstar Beach, Shellmaker Island and part of the upper basin known as Bullnose.
Roughly one-third of the project's funding will come from Proposition 12 funds administered by the California Coastal Conservancy.