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Nuggets of Bay-Delta news—pearls in the ocean of information—curated by the reporters and editors of ESTUARY News magazine.
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The country’s tiniest falcon—the stunning American kestrel—is declining throughout the United States, and California seems especially hard hit: Kestrel numbers during the Golden Gate Raptor Observatory’s annual autumn migration counts declined from nearly 800 in 1997 to just 300 in 2017. “Kestrels in California have been on a long downward trend since 1950 at least,” says GGRO Director Allen Fish, citing several potential reasons for the decline, including predation by other raptors. Pesticides destroy important food sources for kestrels and also sometimes poison the birds themselves. Rodenticides and insecticides work their way up the food chain and cause secondary poisoning, as do heavy metals like selenium, mercury, and lead. Loss of nesting sites is another problem: kestrels are cavity nesters and rely on old woodpecker holes and tree hollows; they do not excavate their own cavities. Very old trees are becoming harder to find in managed forests, says Fish, and dying trees with potential nesting cavities are often treated as fire tinder and removed for safety or aesthetic reasons. The Kestrel Campaign, a Bay Area volunteer group funded by Save Mount Diablo, hopes to help local kestrel populations recover by educating the public about issues like rodenticides, and installing kestrel nesting boxes on public and private land near Mount Diablo. The group installed 24 boxes last year and team leader Brian Richardson says there has been nesting activity in some of them. “Such citizen science operations, along with focused removal of poisons from our environments, together have a great chance of tipping the scales back in favor of this charismatic and useful falcon,” says Fish. LOV
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Though a tiny and low-lying treatment plant on the San Leandro shore is facing increasing regulation of nutrients and rising sea levels, it’s got a path to adaptation thanks to the region’s taxpayers. This April, the San Francisco Bay Restoration Authority awarded the first round of Measure AA grants, including $539,000 for San Leandro’s water pollution control plant. The plant, which is surrounded by blue- and white-collar communities, recently completed upgrades that allow the repurposing of a retired treatment pond. The money will pay for plans, designs, and permit applications necessary to convert the pond to a wastewater treatment marsh and buffer zone between the plant and the advancing Bay—a critical improvement, since just 16 inches of sea level rise could flood 82% of the plant’s infrastructure . “We’re so little, without the right kind of help and a push from outside forces, it would be hard to initiate this kind of project,” says plant manager Justin Jenson. “Outside forces” include the East Bay Dischargers Authority, the San Francisco Estuary Institute, and water quality regulators seeking to reduce the amount of nutrients discharged into San Francisco Bay, which are starting to cause harmful algal blooms. “We’ve seen other experimental green infrastructure systems in Discovery Bay and Oro Loma remove nearly 100% of nutrients at a much lower cost than conventional treatment,” says Baykeeper scientist and SFEI advisor Ian Wren. “Instead of getting more concrete, chemicals, and pumps, the community could see plants and beauty on our shore,” says Jenson. “The grant is a catalyst.” ARO
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Updated guidance synthesizing the best available science on sea-level rise projections and rates for California—including advances in modeling and improved understanding of the potential impact of ice loss from the Greenland and Antarctic ice sheets—is now available from the California Ocean Protection Commission. The State of California Sea-Level Rise Guidance 2018 Update is the second update to guidance originally released in 2010. It is based on the scientific findings of the OPC Science Advisory Team’s 2017 report, “Rising Seas in California: An Update on Sea-Level Rise,” which noted among other findings that California may be particularly vulnerable to sea level rise stemming from ice loss in Antarctica. The guidance “provides a bold, science-based methodology for state and local governments to analyze and assess the risks associated with sea-level rise, and to incorporate sea level rise into their planning, permitting, and investment decisions,” says OPC’s Jenn Eckerle. “It provides a step-by-step approach for state agencies and local governments to evaluate sea level rise projections and related hazard information in decision-making, and identify preferred coastal adaptation approaches to build resiliency.” The document will help cities and counties comply with a new law requiring them to incorporate climate change into their planning efforts, and assist state agencies satisfy a recent Executive Order to prepare for and adapt to climate change. CHT
Photo: Dave Revell
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Nutria — giant South American rodents—are breeding in the San Joaquin Valley and are on the brink of invading the Delta, where they could wreak havoc, as they have done in Louisiana, the Chesapeake Bay and the Pacific Northwest. According to the California Department of Fish and Wildlife, nutria have extremely destructive feeding habits that often lead to severe soil erosion, in some cases converting marsh to open water. Nutria also burrow into banks and levees, creating complex dens that extend as much as 6 meters deep and 50 meters into the bank, often causing severe streambank erosion, increased sedimentation, levee failures, and roadbed collapses. The rodents, which can weigh more than 20 pounds and are often mistaken for beavers or muskrats, were introduced to California for the fur trade in the early 20th century, but were eradicated by the 1970s. In 2017 a reproducing population was discovered in the San Joaquin Valley and nutria have now been confirmed in Stanislaus, Tuolumne, Merced, and Fresno counties, including an area near Grayson that is only about 25 miles south of the Delta. They could reach the Delta all too easily: A single female nutria can have 200 offspring, which can disperse as far as 50 miles. CDFW has launched an eradication program and is asking the public to report sightings to CDFW’s Invasive Species Program.
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Eighteen years after local stakeholders adopted the Putah Creek Accord to guarantee minimum flows and other enhancements, birdlife is flourishing in the Creek’s Riparian Reserve, highlighting the restoration of what was once a dried-up ditch. Former U.C. Davis post-doc Kristen Dybala and her colleagues recently reported in Ecological Restoration on a project that monitored populations of breeding species, mostly songbirds, at the Reserve and 13 other sites along lower Putah Creek from 1999 through 2012. Some sites had seen active restoration efforts to benefit native fish; others had not. Overall, birds seemed to respond to the modified flow regime, with positive trends for 27 species and greater community diversity. Seven riparian-dependent species showed increases in population density, among them the yellow warbler, a California species of special concern as a result of habitat loss and nest parasitism by brown-headed cowbirds. Both riparian-dependent and woodland-associated birds had faster density growth rates than species associated with human-modified areas. Putah Creek has even seen breeding attempts by the endangered least Bell’s vireo, extirpated from the Sacramento Valley more than 80 years ago. Fish monitoring studies show parallel trends. The report concludes that while further progress is possible, the Accord and subsequent actions “have been successful in making long-term improvements to the condition of the lower Putah Creek riparian system for both aquatic and terrestrial organisms.” JE
Photo: Joe Eaton
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Infrastructure improvements could provide safe drinking water to tens of thousands of Californians currently living without it, but funding such improvements remains a challenge. Many communities in rural, unincorporated San Joaquin Valley are served by water systems high in nitrates and arsenic, or private wells not subject to inspection. But according to a new UC Davis study, about 99,000 valley residents live near public systems with clean water and could access it if service extensions, piping and other infrastructure improvements were implemented. Pending state legislation would create a fund for such projects through fees imposed on water districts. While the bill faces opposition from water agencies, it is supported by groups typically at odds, including environmental advocates and farmers. “This is a problem generations in the making, and we need long-term solutions,” says Jonathan London of UC Davis’ Center for Regional Change and lead author of the report. “There is no quick fix.” A sustainable solution could end a century-long story of unsafe water in California’s rural heartland. MHA
Photo: Tracy Perkins
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Napa County voters will weigh in on the fate of the county’s remaining oak woodlands this June, when they cast ballots on Measure C, the Watershed and Oak Woodland Protection Initiative. “Ninety-five percent of oaks on the valley floor are gone and we want to do a better job reducing deforestation on the hills” initiative co-author Jim Wilson, told the Bay Area Monitor. “Our hillsides are beautiful and also filter rain, keeping water clean as it replenishes aquifers.” Most of Napa’s oak woodland loss is due to vineyard development, and the county General Plan projects that another 3,000 acres of woodland will be converted to vineyard by 2030. Current protections require that two replacement oaks be planted or preserved for every mature tree felled, and oaks on slopes steeper than 35 percent and in riparian forests along streams are protected. Measure C would increase the replacement requirement to three trees for every one felled, and extend riparian protections to the ephemeral streams that are dry most of the year but channel rainfall during storms. Beginning in 2030, the initiative would limit the total number of oaks removed. Supporters of the measure include Sierra Club’s Redwood Chapter and the Napa County League of Women Voters; opponents include the Napa Valley Vintners and the Napa County Farm Bureau—and there are local grape growers and vintners on both sides.
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Contributors:
Michael Adamson, Joe Eaton, Robin Meadows, Ariel Rubissow Okamoto, Cariad Hayes Thronson, Lisa Owens Viani
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