Malibu Lagoon Analyzed Four Years After $6.6 Million Restoration

A Snowy Egret takes flight over the Malibu Lagoon while a Blue Heron rests on land in the distance.

From 2012-13, the Malibu Lagoon underwent a nine-month-long restoration process initiated by California State Parks. Twelve acres of wetland near the mouth of Malibu Creek were drained, wildlife was trapped and relocated, heavy equipment scooped out a thousand tons of trash and fill, channels and bridges were removed, banks were reshaped and native vegetation was replanted. The reconfigured lagoon netted two additional acres of wetlands.

Today, four years later, nonprofit The Bay Foundation is preparing to publish the fourth annual Malibu Lagoon Monitoring Report in July (a little late this year because heavy winter rain hampered testing activities). The monitoring will continue until next year, for a total of five years, when the project’s overall success will be assessed. 

The Malibu Times accompanied several staff members on a walk around the lagoon to take a look behind the curtain at how reports are collected. 

Watershed Programs Manager Melodie Grubbs has been coming out to the lagoon monthly and donning a wetsuit to measure oxygen levels, water temperature, salt, turbidity (cloudiness due to particles in the water) and pH in the six- to eight-foot-deep water. Staff also download data from eight automatic data collection stations that continuously monitor algae, nutrients and sediments. Measurements taken during rainy season breaches to the sea are noted. 

“The dissolved oxygen levels in the water keep increasing every year since the restoration and have stayed at high levels post restoration,” Tom Ford, executive director of The Bay Foundation, said. “In addition, there’s decreased stratification, meaning there’s increased mixing of the water from top to bottom, which benefits fish and other wildlife. Another sign of increased health is more benthic invertebrates [organisms with no backbone that live on the bottom or in the sediment, like crabs, starfish, sea urchins, worms and microorganisms], with more pollution intolerant species.”

Ford also reported the amount of sediment decreased and nutrients aren’t accumulating the way they used to. 

“The sediments are flushing out with the tidal cycles when the lagoon is breached,” he said. “The restoration is working. It’s been a dynamic several years and it’s become a dynamic system. We’re very pleased with the results so far — it’s been a categorical success.”

While acknowledging that the lagoon resembled a mud pit when it was first restored because of all the newly planted native vegetation around the edges that stubbornly refused to grow for about the first three years, they’re pleased that plant growth has finally taken off.

When asked why the lagoon became green with thick algae growth in the year or two after restoration, Ford said the earthwork involved in restoration churned up a lot of buried nutrients that caused the algae blooms. “It took time for those nutrients to flux out,” he explained. 

Staff pointed out that, although not directly part of the restoration, native birds, such as western snowy plovers and endangered California least terns were nesting nearby on a section of sand that has been fenced off by State Parks, hoping to keep beachgoers and roaming dogs out. The plovers had not been seen nesting in LA County since 1949 and are listed as federally threatened.

Rosie Dagit, senior conservation biologist for the Research Conservation District of the Santa Monica Mountains, works with a team to conduct lagoon fish surveys for the foundation. 

“All of the native fishes [including the tidewater goby and the jumping striped mullet] have returned with multiple age classes, indicating successful reproduction,” Dagit described in an email. “We documented the first-ever adult steelhead trout in May 2014 — remarkable! Overall, the fish are responding well to the new configuration, with native species dominating non-natives — the reverse of pre-construction conditions.”

Dan Cooper of Cooper Ecological Monitoring, who surveys bird species for The Bay Foundation, has experienced mixed results since the lagoon restoration. 

“We did have twice as many [birds] using the lagoon in 2015-16 as 2013-14, but I’m not sure if it’s due to the lagoon or what’s happening with the three most numerous species there in general — California gulls, brown pelicans and elegant terns,” he emailed. 

“The number of species dipped hard after the first year because the area had so little vegetation, but has been creeping back up,” he continued. “The restoration has increased the habitat for lagoon-dwelling birds that like open water, but it came at the expense of the more threatened marsh-dwelling birds because so much [marsh] vegetation was cleared out.”

Cooper expressed concern about grassland/open-country species like Western Meadowlarks, “which peaked in 2015 with 55, but were down to just a few in 2017,” he wrote. “On the plus side, urban-favoring species like starlings and pigeons are down, and that’s good.”

Editor’s note: This story has been updated, following a request by The Bay Foundation.