Sea level rise has complex ramifications for the entire Los Angeles coastline — especially Ballona

By Sharon Zhang

A king tide swallows the lifeguard tower on Mother’s Beach

In the late 1800s, the landscape of Los Angeles encompassed 14,000 acres of sprawling wetland habitat. Alkaline meadows covered what’s now the path of the 10 Freeway between La Cienega and Crenshaw boulevards; the water table was shallow, making for moist earth. Meadows stretched, unbroken, from the southeastern boundary of L.A. County up to Beverly Hills. Salt flats and salt marshes covered the coastal expanse of Venice and the entirety of Marina del Rey.

Now all that’s left of the once ubiquitous wetland habitat in Los Angeles is the Ballona Wetlands Ecological Reserve, some 600 acres of protected habitat bordering the marina and Playa del Rey.
A concrete levee installed decades ago on Ballona Creek restricts water from flooding the area, drying the wetlands. It’s hard to imagine the historic wetlands now — especially in Marina del Rey, created by dredging subaqueous sediment and dumping it into the adjacent wetlands.

As the only wetlands in Los Angeles proper, Ballona is critical for wildlife. Audubon California has documented more than 300 bird species there, both permanent residents and migratory visitors. For the least tern, fist-sized shorebirds with black “caps,” Ballona serves as a foraging ground while they nest on Venice Beach. Birds are threatened, then, when homeowners on the edges of the wetlands let pets run free in their backyards and beyond.

“You can imagine the devastation cats can do to the bird population and lizard population. They’ll clear out a perimeter around the property,” said Richard Brody, who manages the Ballona Wetlands for the California Department of Fish and Wildlife. Brody often has to go door to door educating those living around Ballona about the ecological significance of their backyards; they may move in next to the wetlands, but think only about the view. Recently, a resident on the edge of the reserve was painting her apartment, washing her brushes and throwing the toxic water into the reserve.

And there’s more than a hint of bitterness when Brody tells me he spends a lot of time on the job “kick[ing] homeless people out” of the wetlands. He’s chased away countless illegal campers and trespassers — people doing drugs and huffing glue and even bicycle chop shop operators — then cleans up after they leave. “That’s what my biology degree has been reduced to,” he said.

Over the years, the wetlands have been subject to the gradual buildup of stressors such as litter, human encroachment and invasive species. The Department of Fish and Wildlife, Coastal Conservancy and the Bay Foundation have been working on conservation plans for the wetlands, promising to release a years-overdue environmental study this summer.

They’ve previously discussed the possibility of clearing away some of the sediment dumped into the wetlands during the creation of Marina del Rey as well as removing the concrete levees along Ballona Creek. Those ideas have faced staunch resistance, however, from environmental groups such as the Sierra Club, who argue that lowering the land to allow tidal flow into the wetlands is destructive to existing habit. Creating one habitat at another’s expense, critics say, is not restoration.

With impending sea level rise, though, flooding parts of the wetland will become inevitable.


This CoSMoS-COAST map shows low-lying areas that will be at high risk of storm-related flooding due to rising seas Image courtesy of Nick Sadrpour / USC Sea Grant

The sea is expected to rise between three and six feet by 2100. By that same year, between 31% and 67% of beaches in Southern California will be completely eroded if nothing is done to protect them. But sea level rise is often brushed off as an issue for the far future.

“Rising sea levels — it’s such a long-term process. For a lot of people, it’s not the first thing they think about with climate change. Because it’s not affecting me today, tomorrow,” said Nick Sadrpour, a science and policy specialist at USC Sea Grant. “However, we know the impacts will be severe so we are planning now to minimize the risks. Cities are using the CoSMoS-COAST tool to help identify vulnerable locations and assets.”

CoSMoS-COAST stands for Coastal Storm Modeling System – Coastal One-line Assimilated Simulation Tool; it’s a U.S. Geological Survey sea level rise and coastal erosion model that communities like Venice and Santa
Monica have been taking data from in order to update local coastal programs with regard to rising seas.

To help people visualize what sea level rise might look like, Sea Grant organizes walks on the coast on days with exceptionally high tides, called king tides. These occur around the winter solstice in December and this winter came as high as seven feet one inch above the mean tide line — on the high end of sea level rise predictions for the next century. Tour participants are encouraged to take pictures. In one from January 2015, the elevated floor of the lifeguard tower on Mother’s Beach in Marina del Rey sits just inches above the waterline.

Scientists and coastal planners are considering options to mitigate the effects of sea level rise and erosion. In Santa Monica, the Bay Foundation is conducting a dune restoration project to test the success of softscaping — a term that describes more natural solutions than hardscaping, such as sea walls. Last December the Bay Foundation seeded the site with native plans. They’re “seeing thousands of little seedlings right now,” said Melodie Grubbs, who manages watershed projects for the organization. “It’s really exciting.”

Over time, mini dunes, or dune hummocks, will form around the plants. Commonly found on the East Coast to protect against storms, the dunes will help absorb wave action and work as a natural wall between the sea and a sidewalk, parking lot, house — whatever’s on the other side.

The issue, though, is that not every beach is as wide as those in Santa Monica. With the project site in place and the Bay Foundation’s goal that two of three acres of dune habitat will be restored, there is still plenty of room for beachgoers to relax. In places with narrower beaches, this sort of softscaping isn’t an option.

“What works in Malibu isn’t going to work for Venice; what works for Venice isn’t going to work for Long Beach,” Sadrpour said. “Those really local decisions are going to have to be made by those communities.”


As for Ballona, as the sea rises and floods the existing wetland basin over the years, wetland habitat will be created on what is now hilly meadow upland habitat. Wetland habitat, which comprises only a quarter of the Ballona Reserve now, about 153 acres, will expand in size.

“As sea level rise occurs, we’ll lose some of the wetlands we have but we’ll gain wetlands along the perimeter,” Brody says. “We can still maintain a few hundred acres of habitat even as we lose some down closer to wetland fringe or tidal fringe” — by which he means the current habitat by the coast and creek.

For peregrine falcons, savannah sparrows and other federally protected birds that use the Ballona wetlands as habitat, sea level rise could create more nesting and feeding area. Inland-dwelling shorebirds like least terns and western snowy plovers may benefit from an increase in habitat as well, but terns and plovers will also lose critical beach habitat with sea level rise.

Researchers don’t know if shorebirds can move freely from inland to coastal habitats, so it’s unclear whether coastal dwelling shorebirds will be able to use the newly-created wetlands as habitat.

But the birds are unlikely to leave their historical habitats, says Kimball Garrett, ornithology collections manager at the Natural History Museum in Los Angeles. “These seabirds are so philopatric,” — meaning that they tend to return to where they were hatched to nest — “it’s not like ‘Oh, we’ll just pick up and leave.’… They’re not that plastic,”
he said.

Shorebirds stand to lose a lot of habitat as the sea floods areas that they normally nest on. For instance, western snowy plovers typically nest on open beach. They “rely on being cryptic,” said Garrett, so they scatter their nests, which blend into the sand. Federally designated as a threatened species, the plovers already face problems of human disturbance and predation. But because of rising seas, many of the plovers’ critical habitats will be partially underwater. A critical habitat in Malibu Lagoon, for example, will be almost entirely underwater with six feet of
sea level rise.

When they’re not tied to a nest, shorebirds may be able to feed in inland habitats like the wetlands, said Garrett. But when historical nesting areas are underwater, snowy plovers — pale, apple-sized birds whose chicks are as small as a thumb — will be in trouble. And with so much uncertainty surrounding the future of the coast and the wetlands, it’s not clear as to whether the species will survive. Part of that future may become clearer when the long-awaited environmental review for the state’s Ballona Wetlands restoration plans is released later this year.

Garrett hopes that coastal planners don’t wait around, though, to protect species. “I always worry that we get too focused on climate change,” he said, “at the expense of also addressing correctible things that are happening right now, impacting habitats and populations.”

 

Sharon Zhang recently graduated from USC, where she served as the science and tech editor for USC Annenberg Media.

Save

Share