Toxins Flock to Beads in a Scientific Tea Bag

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19
Mar

Toxins Flock to Beads in a Scientific Tea Bag

By Ashleigh Papp When a New Zealand scientist shared a novel method to test water quality in the early 2000s that didn’t involve harvesting shellfish, UC Santa Cruz’ Raphael Kudela and his team of researchers quickly adopted the idea. After some fine-tuning, they named their new technique Solid Phase Adsorption Toxin Testing (SPATT, for short). The technique takes advantage of custom-built plastic, or resin, beads that are designed to absorb specific things. “It looks a lot like a tea bag,” says Kudela. So far, SPATT has been used to measure water quality from the Santa Cruz Wharf to the Berkeley Marina and at the mouths of the San Joaquin and Sacramento rivers.
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19
Mar

Tracking Curlews Cross-Country

This winter, Jay Carlisle, director of the Intermountain Bird Observatory, teaming with Nils Warnock of Audubon Canyon Ranch and netting expert David Newstead of Coastal Bend Bays and Estuaries Program, caught two long-billed curlews and outfitted them with transmitters. Those birds may reveal where the wintering curlews on the California coast and Bayshore are coming from.“It’s such a habitat generalist that adapts well to humans,” Carlisle notes...
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19
Mar

Network Listens for Passing Salmon

It’s a cold morning in early February, and Chris Vallee of the U.S. Geological Survey is motoring upriver along Steamboat Slough. Vallee and his team are here to maintain an array of hydrophones used to track migrating native fish. The work is part of a multi-agency effort to provide more timely and detailed information about the movements of salmon, steelhead, and sturgeon in the Central Valley.
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05
Mar

Jan Thompson has always been most interested in what happens down at the bottom of the Bay.

The zone of interaction between the critters in the oozes and the water column above—where specks of sediment, nutrients, and fish food cycle through clam siphons into the Estuary—is the particular specialty of this US Geological Survey scientist. “I’m most proud of the research I’ve done establishing a solid connection between bivalve grazing and phytoplankton growth,” she says. When USGS first hired Thompson, who retired in October 2019, most women in the Menlo Park office were secretaries. She’s since trained dozens of female and minority scientists, and also received the Survey’s first ever diversity award. “I learned a lot from hiring a bunch of kids who weren’t like me,” says Thompson, who describes herself as “middleclass white bread.” As a...
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05
Mar

Rainer Hoenicke is optimistic about the changes he saw in his five years as the Delta Stewardship Council’s Science Director.

“People are coming to the table and realizing we need to be anticipating and forecasting how to adapt,” he says. Prior to joining the Science Program, Hoenicke served for nearly a decade as deputy and executive director of the San Francisco Estuary Institute, where he managed two Boards of Directors and reorganized the Institute’s program areas. “I felt challenged to do something different,” he says of the move, “since the Delta is much more controversial territory.” In Hoenicke’s eyes, the capstone to his career came in October 2018. The U.S. Bureau of Reclamation increased its science allocation for California, and it and the Council were able to use pre-existing proposal submittal and evaluation infrastructure developed by the California Department of...
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22
Jan

A new system for treating agricultural drainage water in the Delta could also help rebuild subsided islands.

The approach—known as a Chemically Enhanced Treatment Wetland—combines chemical treatment with natural wetland processes; researchers tested it on Twitchell Island, which features corn and rice crops, as well as wetlands. They dosed agricultural ditch water with dissolved organic material (DOM), then treated it with a coagulant to precipitate the DOM, forming flocculant. The resulting water then passed though treatment wetlands, where the flocculant settled and blended with plant detritus in the sediment. The study, reported in the September 2019 San Francisco Estuary and Watershed Science, found that the combined system removed drinking water contaminants including dissolved organic carbon, disinfection byproduct precursors, and methylmercury. Another possible benefit is subsidence reversal: the researchers found that sediment and carbon accreted about four times...
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22
Jan

Manmade features in the Delta, including riprap-armored banks, water diversion pipes, pilings, and woody debris, may be sending juvenile native fishes into the jaws of finned invaders.

“We know from a decade of doing survival studies that migrating juvenile salmon are dropping out of the system pretty much everywhere in the Delta,” says UC Santa Cruz fisheries biologist Brendan Lehman. “Physical habitat features are potentially aggregating predators and prey in ways detrimental to salmon smolts and steelhead.” The scientists report in the December 2019 San Francisco Estuary and Watershed Science that artificial light and submerged aquatic vegetation pose the most severe and widespread risks to native fishes. Plants like Brazilian waterweed form dense underwater mats across vast reaches of the Delta. These mats have nurtured a rise in predatory bass populations and force prey fish into exposed channel centers. The artificial lighting pervasive along docks and buildings...
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22
Jan

Levels of pyrethroid insecticides spike sharply in the North Delta’s Cache Slough during winter rainstorms, rendering the water so toxic that it decimates laboratory populations of a half-inch crustacean called Hyalella azteca.

However, according to a study reported in the September 2019 San Francisco Estuary and Watershed Science, Hyalella collected in the wild from Cache Slough are resistant to pyrethroids. Genetic analysis revealed that, collectively, Hyalella in the slough have four mutations for pyrethroid resistance. They also have a fifth mutation for resistance to organophosphates and likely carbamates, two additional major classes of pesticides that are applied extensively on agricultural and urban lands. “Hyalella are special,” explains co-author Helen Poynton, a molecular ecotoxicologist at the University of Massachusetts in Boston. “They reproduce quickly and have a short life span, which makes them highly adaptable.” Pesticide interests have seized on findings of pyrethroid resistance in Hyalella elsewhere in the wild to argue that...
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22
Jan

Researchers hope new computer models will help clarify the effects of entrainment on the population of endangered Delta smelt.

Entrainment at the South Delta pumps of the State Water Project and the Central Valley Project has been a concern for years, but disentangling its impact on the dwindling smelt population from those of other environmental and water management factors isn’t easy, and operational differences between the SWP and CVP facilities complicate analysis. Now, US Fish and Wildlife Service statistician Will Smith has developed computer models for entrainment effects on different smelt life stages, part of a larger Delta Smelt Life Cycle project being rolled out this month; his model of adult smelt entrainment was published in the December issue of San Francisco Estuary and Watershed Science (a separate model for postlarval smelt will appear in another journal). “Adults exhibit...
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22
Jan

While the acreage of wetland restoration projects is growing throughout the Delta, scientists are still working to understand how best to help these areas become fully functioning, complex habitat as quickly and successfully as possible.

A study published in September’s San Francisco Estuary and Watershed Science shed light on some essential questions about what triggers seed generation in wetland habitat. “Wetland restoration practices can be enhanced by a solid understanding of basic plant life history and species ecology,” says co-author Taylor Sloey of Yale-NUS College in Singapore. The researchers looked at three questions: what seeds are present in the seed bank (the viable seeds that accumulate naturally in the soil), and how exposure to cold and flood affects their germination. The study was based on seed bank samples taken from wetlands on the Delta’s Liberty Island. Though the island was drained and farmed throughout most of the 20th century, it has been naturally recolonized by...
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22
Jan

A recent test found more than 250 chemicals in the Delta’s Cache Slough, but “Dr Doom” says figuring out what they all are, and their concentrations, is beside the point in our efforts to understand stressors on native fish resilience.

“Knowing the effect on the fish is more informative than knowing which chemicals may be causing it,” says UC Davis’ Richard Connon (whose colleagues gave him his sinister title), referring to taking an ecological rather than regulatory perspective on fish health, and also to the less obvious sublethal effects of contaminants on fish behavior and reproduction. Connon is the lead author of a wide-ranging journal article in the December 2019 issue of SFEWS on how to better focus contaminants research in the Delta, and how to use more advanced tools to get at the synergistic and additive effects of multiple contaminants and stressors. Despite decades of monitoring, gigabytes of available data, and significant regulatory oversight, there remains “major uncertainty” on...
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05
Dec

Speakers discuss forward-looking science in a rapidly changing environment, and the neuroscience of persuading people to care about climate change.

Climate Change Planning Mark Gold made the ultimate comment in his opening plenary at the State of the Estuary Conference: “The age of incrementalism, and not moving forward in a bold way, is not getting it done in terms of climate change.” Gold, deputy secretary for ocean and coastal policy for the California Natural Resources Agency, outlined the state’s newly revised strategic plan for a bluer economy, coastal resilience, and rapid response to fisheries emergencies. Following his talk, Geeta Persad of the Union of Concerned Scientists reviewed various challenges facing California. “Climate change is going to fundamentally transform where and when California gets its water,” she said. Later, the Delta Stewardship Council’s Yumiko Henneberry asked a panel of scientists what...
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05
Dec

Not So Picky Marsh Mouse

The endangered salt marsh harvest mouse (informally “Salty”) is a poster child for tidal marsh restoration in San Francisco Bay. But recent research, presented by University of California at Davis postdoc Katie Smith in a State of the Estuary conference session on tidal wetlands, suggests we’ve misinterpreted what the mouse needs. “It’s been managed as a habitat specialist,” she said, based on assumptions that it requires tidal wetlands and a diet of pickleweed. However, hours of mouse-tracking around the Bay show that it also thrives in managed wetlands and eats a variety of plants, including non-native species. Although restoration projects have created high-tide refuges for the mice, Smith’s preliminary data suggest other rodent species exclude them from those sites. That...
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05
Dec

Speakers discuss issues facing Estuary wildlife and their wetland habitats, as well as drones and other new tools that will help future management.

Fish and Wildlife Check-up State of the Estuary Conference presentations featuring decades of data on fish, ducks, seabirds, and cetaceans revealed both hopeful and alarming trends. “The loss of federal funding for the midwinter waterfowl survey, usually conducted using small aircraft, has researchers looking at drone-based alternatives,” said waterfowl biologist Susan De La Cruz of the US Geological Survey. The overall community condition of the Estuary’s fish (abundance, distribution, diversity, proportion of native to non-native species) has declined, reported the National Resources Defense Council’s Christina Swanson, citing the 2019 State of the Estuary Update, Bay Study and other surveys. The breeding success of California least terns and Brandt’s cormorants reflects the status of the forage fish they feed on, according...
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19
Sep

Drones Pilot Vegetation Mapping

By Michael Hunter Adamson In the world of conservation, as attested to by multiple speakers at a late summer UC Davis event, drones, or UAVs (unmanned aerial vehicles) may be the vehicle of choice for mapping the future of invasive plant management in the Delta. The California Department of Water Resources began using UAVs in earnest after the Oroville dam failure in the winter of 2017, when drones offered visuals no one could get near on the ground. The Blacklock Ranch, a leveed island in Suisun Marsh, offers a more current example of how drones are now being employed at restoration sites. “We are using our UAVs and multispectral [red, blue, green, and infrared spectrums, for example] capabilities to map...
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08
Aug

Invasive clams and freshwater exports from the Delta have created dramatic and unsustainable changes in the San Francisco Estuary’s foodweb over the past 50 years.

 A study by UC Davis researchers found a 97% decline in phytoplankton, the microscopic foundation of the food chain. “Understanding the causes for the decline in the pelagic [water column] community is essential so that efficient solutions can be implemented,” says Bruce Hammock, a research scientist at the UC Davis School of Veterinary Medicine’s Aquatic Health Program. The invasive clams (Potamocorbula amurensis), originally from Asia, have been over-consuming phytoplankton and zooplankton for more than 30 years, and have long been understood to account for part of the fish population’s decline; the new study investigated the additional effects of exports. Beginning in the 1940s, fresh water from the Delta has been pumped by the federal Central Valley Project and the State...
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08
Aug

New shoreline strategies piloted in Puget Sound could help young fish in urbanized estuaries elsewhere.

When Seattle rebuilt its seawall in 2017, they hoped to make the hardened shoreline a little less daunting for the young salmon that hug it closely on their journey to the ocean. Project managers took a three-pronged approach. First, they added texture and complexity into the new concrete seawall to encourage invertebrates, food for the young fish, to settle in nooks and crannies and on horizontal “shelves” built into the wall. Mussels, ecosystem engineers, have settled on the shelves and attracted many other organisms. Next, they installed a habitat “mattress” in the seafloor in front of the wall. This horizontal structure of mesh-covered rocks lifts the seafloor, calms waves, and encourages the growth of kelp and invertebrates for the salmon....
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17
Jun

Tailing a Thrush

By Joe Eaton Researchers like Point Blue Conservation Science ecologist Tom Gardali have equipped Swainson’s thrushes, weighing just over an ounce, with tiny, one-gram GPS tags. If recovered, the tag shows the thrush’s exact winter destination, information vital to border-crossing conservation efforts. “You only get a few readings,” says Gardali, “and you still need to get the tag back. But GPS goes to a spot on the map. This is Holy Grail stuff.”  Sierra/Cascade thrushes were presumed to migrate to Mexico like their coastal cousins. When researchers included thrushes from Mount Lassen and Lake Tahoe in their GPS tracking, they learned otherwise. “The mountain birds are going from Mexico to Panama, possibly as far as Columbia.”
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06
May

Louise Conrad sees the Delta Stewardship Council’s science program, which she now leads, as poised to shift into a new gear – from breaking down the science landscape and building a new foundation for Delta science to actually doing it.

 “With the update of the Delta science plan done, we can now can sink our teeth into some topical issues our scientists can be passionate about, such as aquatic invasive vegetation, microcystis and climate change, for example,” says the former Department of Water Resources (DWR) fish biologist. Conrad grew up in Philadelphia and developed an interest in conservation on summer road trips to western national parks in their family’s Dodge Ram. “My mom sewed us individual seat covers with pockets for entertainment items,” she says.  She is pleased to be part of an agency with so many women in leadership positions and with such a broad mandate. At DWR, she says, legal mandates required them to focus on water project...
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23
Apr

New Video: USGS Investigates 50-Year Mystery of San Francisco Bay

Between April 1969 and March 2019, USGS conducted 1,167 boat-based sampling cruises to better understand changing conditions in San Francisco Bay — producing data used by scientists around the world. Meet four scientists and the captain of the March 14, 2019 cruise, and watch them plumb the Bay depths, drag nets, filter samples, and explain their work.
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