Researchers are applying a novel genetic technique as part of the development of an annual estimate for the number of juvenile spring-run Chinook salmon entering the Delta.
The technique, spearheaded by geneticist Melinda Baerwald from the California Department of Water Resources, allows researchers to accurately distinguish young spring-run salmon from other runs by targeting DNA sequences specific to these fish. In a paper published in San Francisco Estuary and Watershed Science, lead authors Baerwald and Peter A. Nelson explain some of the challenges of developing this estimate, called the spring-run juvenile production estimate. A key hurdle is differentiating spring-run fish from salmon that migrate during other...Read More
The Sacramento-San Joaquin Delta contains more than 50 peat islands. Most have subsided—some as much as three meters — as a result of drainage for farming, and must maintain artificial water tables below the land surface via managed pumping. According to researchers from the University of California at Santa Cruz and the US Geological Survey, these pump stations are an underappreciated source of nutrients in nearby waters, with potentially significant implications for habitat and water quality. To get a...Read More
Several projects in the lower Sacramento River and Delta have been exploring strategies for increasing the quantity and quality of food for migratory and resident fish. As part of a broader whole-ecosystem experiment that added nitrogen into the Sacramento River Deep Water Ship Channel, Leah K. Lenoch and colleagues at USGS and UC Davis looked into the channel’s hydrodynamics to explore whether the environmental conditions there hold promise for increasing the quantity of phytoplankton (the microscopic algae at the base...Read More
The path into a career is not always a straightforward one. “I hated school. I mean, hated school,” says Denise Colombano, a postdoctoral fellow and Delta Science Fellow working on fisheries research at UC Berkeley. Today, Colombano feels that it is important to talk about her story as a way of encouraging inclusiveness and opportunity within her field — and in the sciences in general. “I actually flunked ninth grade, and was attending a continuation school, when my science teacher...Read More
For the second time in four years, a proposal for a voluntary agreement between agencies and water contractors on flows into and through the Delta from the San Joaquin and Sacramento rivers and their tributaries is wending its way through the State Water Resources Control Board. The proposal, which would replace the regime outlined in the Board’s most recent update to the Bay-Delta Plan, calls for substantially less water remaining in the system than the update, but comparing the two...Read More
Morning at Suisun Marsh is a living watercolor with a soundtrack. Miles of tule and pickleweed populate the foreground, split by canals glinting silver from the sun. In May, the hills undulate across the northern boundary in classic California gold. A red-tailed hawk’s iconic hoarse screech punctuates the insectine buzz as it takes off from a powerline. At 7:40 AM, it’s already 72 degrees and there’s no trace of a breeze. I’ve come to visit the Marsh from downtown Oakland...Read More
Dutch Slough in Oakley, on the southern edge of the Sacramento-San Joaquin Delta, is less than a mile from where biometeorologist Dennis D. Baldocchi (above) grew up on his parents’ orchard and fished with pals in nearby Marsh Creek. In October 2021, the California Department of Water Resources breached the levees here, restoring nutrient-rich tidal flows to degraded ranchland. Early in the 20th century, Baldocchi’s father grew dry beans and sugar beets on the peat soils of the Delta’s Liberty...Read More
Why not richer rice fields, more wetlands, better boat launches, extended trails, even eco-tourism? ? A new survey for the Delta Islands Adaptation Project, funded by a Prop 1 Watershed Restoration Grant, wants the public’s opinion on the importance of 10 possible land-use objectives leading to the selection of one of the four islands for improvements. As your blinking cursor hovers over a satellite image of Bouldin, Bacon, Webb, and Holland Tracts, the survey lays out all that the experts...Read More
The seasonal bias suggests flows were overestimated during the summer months and underestimated during the winter. Estimates of Delta outflow use a measurement called net Delta outflow index (NDOI), which is determined by taking the amount of Delta inflow, from sources such as the Calaveras, Sacramento, and San Joaquin rivers, and subtracting Delta exports, a direct measurement, and net Delta channel depletions. A team led by TetraTech’s Paul Hutton compared NDOI estimates against measured Delta outflow at four points, as...Read More
According to a new study published in San Francisco Estuary and Watershed Science, even surveys that target the same part of the water column can come up with significantly different catches. The study’s authors analyzed decades worth of data from the California Department of Fish and Wildlife (CDFW) Fall Midwater Trawl, which spans from San Pablo Bay to the upper Delta; CDFW’s San Francisco Bay Study midwater and otter trawls, covering the South Bay to the central Delta; and the...Read More
A research team led by UC San Diego’s John Helly processed 15 years’ worth of water-use data from the state’s Department of Water Resources, reporting in the March 2022 issue of San Francisco Estuary and Watershed Science that while “the annually precipitated water supply in the Bay-Delta” varied by 30%, agricultural water use scarcely changed year to year. “The water management system maintained nearly constant agricultural water use even in periods of intense drought, with year-to-year variation of about 7%,”...Read More
West Coast salmon and steelhead populations have declined steeply in the past century – a plight that biologists have primarily blamed on habitat loss. Dams, for instance, block adult fish’s access to historic spawning grounds, and juvenile survival is impacted by streamside development and water diversions. Now, it turns out, microplastic pollution may be a much bigger factor than anyone knew just several years ago. In 2019, scientists with the San Francisco Estuary Institute and the Los Angeles-based nonprofit 5...Read More
Longfin smelt were what hooked Jim Ervin when he first learned about the UC Davis South Bay Fish Survey through a presentation at the 2012 Bay-Delta Science Conference. “They were catching them right there in our effluent channel!” recalls Ervin, a self-trained naturalist and former compliance manager for the San Jose-Santa Clara Regional Wastewater Facility. Intrigued, he contacted the researchers, rode with them on their next survey, and has been part of the project ever since, devoting more time to...Read More
Twelve years ago, scientists at UC Davis began a survey of the southern end of San Francisco Bay — the Lower South Bay — to see how fish responded to the South Bay Salt Ponds Restoration Project. They discovered an unexpectedly diverse and robust aquatic community and a previously unknown spawning ground for the longfin smelt (Spirinchus thaleichthys), listed as endangered in California and a candidate for federal protection because of its declining numbers. The team, led first by Jim...Read More
As a source of flowing water, upper Coyote Creek is unreliable at best. Though storms swell its banks in winter, Mediterranean-climate summers shrink this South Bay stream to a series of isolated pools by August. “By October right before the rains come, we’re down to these really small pools that have all the fish in them,” says retired U.S. Environmental Protection Agency ecologist Rob Leidy. Leidy and UC Berkeley fish ecologist Stephanie Carlson began monitoring the annual dry-down of upper...Read More
On a mild day between rainstorms in mid-December, wildlife biologists outfitted in rubber boots and orange lifejackets load drum after drum of precious cargo onto a small boat docked in Rio Vista, a town on the Sacramento River in the Sacramento-San Joaquin Delta. There is little fanfare but the occasion is nonetheless momentous. The shiny silver drums contain thousands of Delta smelt — finger-size imperiled fish unique to the Delta — that were raised in a conservation hatchery. Today marks...Read More
The method, being practiced along the Sacramento River, mimics the flood patterns of natural Sacramento Valley wetlands by diverting water onto floodplain farm fields, retaining it there for three weeks, and finally flushing the water—now rich with zooplankton and invertebrate protein—back into the river. Onsite studies have shown that salmon smolts grow faster when provided with this supplemental nutrition source, giving the method promise as a tool for boosting survival rates of outmigrating juveniles and, ultimately, helping sustain imperiled Chinook...Read More
Seagrass meadows, kelp forests, and even the seabed can all lock away carbon—but exactly how much is still up in the air for these and other ocean ecosystems. The Seascape Carbon Initiative, a partnership formed in late 2021 between four environmental problem-solving organizations and one independent carbon verifier, is pushing the science forward so protecting and restoring these valuable ecosystems can join mangrove forests and terrestrial forests as certifiable nature-based carbon capture projects. “Conceptually, the science is pretty good,”...Read More
“Our goal was to improve estuarine habitat by increasing net flows through the Cache Slough Complex to enhance downstream transport of lower trophic-level resources, an important driver for fish such as the endangered Delta Smelt,” write the authors—including esteemed (and recently retired) California Department of Water Resources lead scientist Ted Sommer—in the latest issue of San Francisco Estuary and Watershed Science. The pulse occurred over three weeks in July, a time when flows in the region above Cache Slough are...Read More
The CRISPR technique used to edit DNA has been formulated into a tool that can distinguish between similar-looking California fish species for conservation research. Called SHERLOCK (Specific High-sensitivity Enzymatic Reporter unLOCKing), the tool can tell the difference between species with speed and accuracy. Better yet, it is both inexpensive and can be run while researchers are in the field. “It puts the power in the hands of the field biologist to make the most informed decision versus waiting sometimes days...Read More
Nothing could be stranger than sitting in the dark with thousands of suits and heels, watching a parade of promises to decarbonize from companies and countries large and small, reeling from the beauties of big screen rainforests and indigenous necklaces, and getting all choked up.
It was day two of the September 2018 Global Climate Action Summit in San Francisco when I felt it.
At first I wondered if I was simply starstruck. Most of us labor away trying to fix one small corner of the planet or another without seeing the likes of Harrison Ford, Al Gore, Michael Bloomberg, Van Jones, Jerry Brown – or the ministers or mayors of dozens of cities and countries – in person, on stage and at times angry enough to spit. And between these luminaries a steady stream of CEOs, corporate sustainability officers, and pension fund managers promising percentages of renewables and profits in their portfolios dedicated to the climate cause by 2020-2050.
I tried to give every speaker my full attention: the young man of Vuntut Gwichin heritage from the edge of the Yukon’s Arctic National Wildlife Refuge who pleaded with us not to enter his sacred lands with our drills and dependencies; all the women – swathed in bright patterns and head-scarfs – who kept punching their hearts. “My uncle in Uganda would take 129 years to emit the same amount of carbon as an American would in one year,” said Oxfam’s Winnie Byanyima.
“Our janitors are shutting off the lights you leave on,” said Aida Cardenas, speaking about the frontline workers she trains, mostly immigrants, who are excited to be part of climate change solutions in their new country.
The men on the stage, strutting about in feathers and pinstripes, spoke of hopes and dreams, money and power. “The notion that you can either do good or do well is a myth we have to collectively bust,” said New Jersey Governor Phil Murphy whose state is investing heavily in offshore wind farms.
“Climate change isn’t just about risks, it’s about opportunities,” said Blackrock sustainable investment manager Brian Deese.
But it wasn’t all these fine speeches that started the butterflies. Halfway through the second day of testimonials, it was a slight white-haired woman wrapped in an azure pashmina that pricked my tears. One minute she was on the silver screen with Alec Baldwin and the next she taking a seat on stage. She talked about trees. How trees can solve 30% of our carbon reduction problem. How we have to stop whacking them back in the Amazon and start planting them everywhere else. I couldn’t help thinking of Dr. Seuss and his truffala trees. Jane Goodall, over 80, is as fierce as my Lorax. Or my daughter’s Avatar.
Analyzing my take home feeling from the event I realized it wasn’t the usual fear – killer storms, tidal waves, no food for my kids to eat on a half-baked planet – nor a newfound sense of hope – I’ve always thought nature will get along just fine without us. What I felt was relief. People were actually doing something. Doing a lot. And there was so much more we could do.
As we all pumped fists in the dark, as the presentations went on and on and on because so many people and businesses and countries wanted to STEP UP, I realized how swayed I had let myself be by the doomsday news mill.
“We must be like the river, “ said a boy from Bangladesh named Risalat Khan, who had noticed our Sierra watersheds from the plane. “We must cut through the mountain of obstacles. Let’s be the river!”
Or as Harrison Ford less poetically put it: “Let’s turn off our phones and roll up our sleeves and kick this monster’s ass.”
4th California Climate Change Assessment Blues
by Isaac Pearlman
Since California’s last state-led climate change assessment in 2012, the Golden State has experienced a litany of natural disasters. This includes four years of severe drought from 2012 to 2016, an almost non-existent Sierra Nevada snowpack in 2014-2015 costing $2.1 billion in economic losses, widespread Bay Area flooding from winter 2017 storms, and extremely large and damaging wildfires culminating with this year’s Mendocino Complex fire achieving the dubious distinction of the largest in state history. California’s most recent climate assessment, released August 27th, predicts that for the state and the Bay Area, we can expect even more in the future.
The California state government first began assessing climate impacts formally in 2006, due to an executive order by Governor Schwarzenegger. California’s latest iteration and its fourth overall, includes a dizzying array of 44 technical reports; three topical studies on climate justice, tribal and indigenous communities, and the coast and ocean; as well as nine region-specific analyses.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.
For the first time, California’s latest assessment dives into climate consequences on a regional level. Academics representing nine California regions spearheaded research and summarized the best available science on the variable heat, rain, flooding and extreme event consequences for their areas. For example, the highest local rate of sea level rise in the state is at the rapidly subsiding Humboldt Bay. In San Diego county, the most biodiverse in all of California, preserving its many fragile and endangered species is an urgent priority. Francesca Hopkins from UC Riverside found that the highest rate of childhood asthma in the state isn’t an urban smog-filled city but in the Imperial Valley, where toxic dust from Salton Sea disaster chokes communities – and will only become worse as higher temperatures and less water due to climate change dry and brittle the area.
According to the Bay Area Regional Report, since 1950 the Bay Area has already increased in temperature by 1.7 degrees Fahrenheit and local sea level is eight inches higher than it was one hundred years ago. Future climate will render the Bay Area less suitable for our evergreen redwood and fir forests, and more favorable for tolerant chaparral shrub land. The region’s seven million people and $750 billion economy (almost one-third of California’s total) is predicted to be increasingly beset by more “boom and bust” irregular wet and very dry years, punctuated by increasingly intense and damaging storms.
Unsurprisingly, according to the report the Bay Area’s intensifying housing and equity problems have a multiplier affect with climate change. As Bay Area housing spreads further north, south, and inland the result is higher transportation and energy needs for those with the fewest resources available to afford them; and acute disparity in climate vulnerability across Bay Area communities and populations.
“All Californians will likely endure more illness and be at greater risk of early death because of climate change,” bluntly states the statewide summary brochure for California’s climate assessment. “[However] vulnerable populations that already experience the greatest adverse health impacts will be disproportionately affected.”
“We’re much better at being reactive to a disaster than planning ahead,” said UC Berkeley professor and contributing author David Ackerly at a California Adaptation Forum panel in Sacramento on August 27th. “And it is vulnerable communities that suffer from those disasters. How much human suffering has to happen before it triggers the next round of activity?”
The assessment’s data is publicly available online at “Cal-adapt,” where Californians can explore projected impacts for their neighborhoods, towns, and regions.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.