What happens once wetland structure and function has been restored? How quickly do birds, fish, and other creatures begin using the new habitat, and which species are first responders? How valid are our assumptions about which habitat types are best for focal species? Three speakers wrapped up the restoration session on Wednesday afternoon with considerations of those questions.
First up, Sarah Estrella of the California Department of Fish and Wildlife discussed the status of the northern salt marsh harvest mouse (Reithrodontomys raviventris halicoetes) in Suisun Marsh. Listed as endangered since 1970, the rodent is “characterized by cuteness,” reddish-brown fur, and a docile disposition. “In the past, there was thought to be a strong association between the mouse and pickleweed,” she said. “Those of us working in the marsh suggested they were not so limited in habitat.” A two-year mark-and-recapture study compared abundance, reproduction, and survival in pickleweed versus mixed vegetation (bulrush, fat hen, alkali heath, and others), and in tidal marsh versus diked wetlands. Among other results, harvest mouse densities were found to be higher in mixed vegetation than in pure pickleweed, at least in tidal areas, and higher in diked than in tidal marsh. However, tidal marshes did have higher post-winter survival. A more recent telemetry study challenged another assumption: “We had assumed they move up in elevation at high tide. Instead, they primarily remain in emergent vegetation over standing water when the tide comes in.” Estrella noted that the draft US Fish & Wildlife Service recovery plan covering the mouse calls for extensive conversion of diked wetland to tidal: “Even though diked wetland supports higher densities, it’s considered lower-quality habitat due to its artificial state. Additonally, many habitat models used in environmental documents fail to recognize the spectrum of vegetation types the mice thrive in.” Her recommendation: “Habitat management efforts should include mixed vegetation types, both tidal and diked wetlands, and areas where sea level rise can be accommodated.”
The most conspicuous inhabitants of wetlands, birds are easier to monitor than mice—and their responses can help reveal unintended consequences of restoration and inform adaptive management. Catherine Burns of the San Francisco Bay Bird Observatory reported on three studies of avian reactions to the South Bay Salt Pond Restoration Project. California gulls (Larus californicus), whose populations have increased exponentially in the South Bay, prey on the eggs and nestlings of other birds, including sensitive species. Burns reported that the breaching of Pond A6 in the Alviso complex displaced one of the largest gull colonies. That eased predation pressure on a nearby colony of Forster’s terns (Sterna forsteri), where chick survival increased. Snowy plovers (Charadrius nivosus) pose a different kind of management dilemma, since they nest on salt pannes that will be converted to tidal marsh. “The South Bay project aims to increase plover numbers while decreasing preferred breeding habitat, packing more of them into a smaller area,” Burns explained. Plovers are also vulnerable to gulls and other predators. The good news: nests in experimental plots covered with oyster shells show higher survival rates. As for one downside of restoration, Burns reported that analysis of Forster’s tern eggs confirm concerns that the process would mobilize mercury in pond sediments. From 2010 to 2011, mercury concentrations in tern eggs increased by an average 74 percent in restored ponds as compared with reference ponds, and exceeded toxicity thresholds 100 percent of the time. However, mercury levels in American avocet (Recurvirostra americana) eggs at the same sites did not change. “It’s been challenging,” she summed up. “We need to analyze the responses of a variety of waterbirds. It’s not going to be easy to sort out all these responses. We’re really learning a lot through monitoring.”
The session’s final speaker, UC Davis fish biologist James Hobbs, gave an update on how fish are using South Bay salt ponds that have been reconnected to the Bay. Bottom line: “The restored ponds are quickly used by fish”—and over 85 percent of the 30,000-plus fishes sampled were native species. Restoration has provided over 1,800 acres of new subtidal habitat. Since 2010, Hobbs and his crew have been surveying recently breached ponds at Bair Island, the Alviso/Coyote Slough complex, and Eden Landing, using trawls and hook-and-line angling. Numbers and diversity are highest at Alviso, the largest complex, and lowest at Eden Landing, breached only in 2010. Although the species mix varied among the sites, Pacific staghorn sculpins (Leptocottus armatus) were the most abundant in all three. Hobbs also reported seasonal changes in the species assemblage, with more pelagic types in winter. Overall, fish that can tolerate low dissolved oxygen are more abundant. The survey documented the highest abundance of mysid shrimp, the favored prey of the threatened longfin smelt (Spirinchus thaleichthys), in the Estuary. Leopard sharks (Triakis semifasciata) are visiting the Eden Landing pond: “The pond breaches serve as predator hotspots, which is good as long as the predators are native. Pond production is translating up the food chain, providing benefits to fish in the Bay.”
Bird & Fish Numbers Up
Mercury News -Leopard Sharks in Salt Ponds
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By Ariel Rubissow Okamoto
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.”
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.