San Francisco Bay is becoming less opaque as the sediments power-washed into the Estuary by miners so long ago gradually disperse. This lets sunlight penetrate deeper into the water, creating more favorable conditions for the kind of problematic algal blooms that can shut down crab fisheries and keep people and their pooches out of the water. Scientists have collaborated on some new computer models, however, that may help them predict where and when nutrients, like nitrogen and phosphate from discharges and runoff, may exacerbate the situation.
“It’s still a turbid estuary,” says the San Francisco Estuary Institute’s Dave Senn. “But there’s been a relaxation of some of the things keeping a lid on algae growth.”
Scientists at SFEI are collaborating with the US Geological Survey and a Dutch research institute to build and share new, open-source, state of the art models of local nutrient dynamics based not only on hydrology but also on physics, chemistry, and biology. This ambitious modeling endeavor is being funded by the Regional Monitoring Program and the San Francisco Bay Nutrient Management Strategy.
Senn says the new models will be important tools for quantifying how excess nutrients influence water quality today, as well as for forecasting conditions under future scenarios, like what could happen to algae growth if sediment concentrations go down by another 50 percent. The models can help investigate the effects of seasonal and spatial variations in turbidity, the mixing by the strong tides in the Bay, and how the abundance of grazing organisms like clams keep algal growth in check.
The models will also help wastewater managers answer questions about actions they might take to mitigate or prevent impairment of the Bay in certain areas, and to identify nutrient concentrations that will be protective of ecosystem health, says Senn. Data on past algal blooms and other events are being used to calibrate and validate the models, which can then be re-run to test various management strategies, says SFEI’s Rusty Holleman.
“If you see in the observational record that one day chlorophyll was alarmingly high in a spot, and then two months later not there at all, you could do a lot of reasoning based just on those observations,” says Holleman. “But if we can replicate that in a model, we can pick apart the factors and then test hypotheticals.”
Other specific issues the models could help elucidate are the spatial influence of nutrient loads from each nutrient source, including wastewater outfalls and nonpoint sources like storm drains and creeks, and how sloughs and ponds at the margins of the Bay affect water quality, among many others.
East Bay Dischargers Authority General Manager Mike Connor says information gleaned from the new models could also help wastewater managers figure out if some parts of the Bay will need to be managed differently than others. “Right now the North and South Bays have very similar nutrient levels but very different chlorophyll responses. We suspect the newly restored salt ponds in the South Bay may be acting as little reactors that grow algae and then feed it back into the Bay, but these kinds of processes may work differently in the North Bay. The models will allow us to test different potential management strategies without having to do giant experiments in the Bay.”
The Regional Water Board’s Tom Mumley says his agency is developing nutrient water quality objectives and permit implementation requirements. “Given the significant costs of potential current and future nutrient management scenarios, our modeling investments will definitely yield decision dividends.”
Ultimately, say Connor and Senn, the modeling results could be used to help structure a nutrient credit or trading system for wastewater dischargers in the Bay, similar to carbon trading. But a key difference is that the atmosphere is well mixed with carbon from emissions around the globe — while the Bay is not well mixed. “You’re not going to influence summertime nutrient levels in South Bay by adjusting the inputs in Suisun Bay,” says Senn. “But that’s where the modeling can be really helpful; it takes into account nutrient inputs from each location and their transport and biogeochemical reactions when estimating how they contribute to nutrient concentrations in space and time.”
Lisa Owens Viani is a freelance writer and editor specializing in environmental, science, land use, and design topics. She writes for several national magazines including Landscape Architecture Magazine, ICON and Architecture, and has written for Estuary for many years. She is the co-founder of the nonprofit Raptors Are The Solution, www.raptorsarethesolution.org, which educates people about the role of birds of prey in the ecosystem and how rodenticides in the food web are affecting them.
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When a team of fish biologists was tasked with restoring spring-run Chinook salmon in the San Joaquin River in 2006, none of them quite knew where to begin. The thirsty farms that crowd the river on both sides had taken almost all the water out of it most years since...
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.
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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.