Day

December 15, 2021
15
Dec

Scientists in the Central Valley are honing a novel way of giving young salmon the nourishing benefits of wintertime floodwaters without undertaking costly floodplain restoration work.

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 runs.     Jacob Katz, a California Trout biologist helping lead the project, explains that flushing river water over dry land and then back into the river effectively “reenergizes the food web,” allowing terrestrial carbon to flow into the water where...
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15
Dec

Hot off the press, Sacramento County Breeding Birds: A Tale of Two Atlases and Three Decades of Change raises red flags for some of the county’s wetland species.

Breeding bird atlases use field observations to record possible, probable, or confirmed nesting in uniform-sized blocks within a county or state. Biologist/artist Tim Manolis led a Sacramento County atlas project in 1988-93, but the results were never published. When Edward Pandolfino of Western Field Ornithologists heard about it he suggested repeating the effort and packaging the two data sets together. The second Sacramento atlas, covering 2016-20, followed the lead of recent state atlases in the eastern US in using data uploaded to the birding app eBird to supplement targeted observations. “It’s a lot more efficient, and lets everybody get involved,” says Pandolfino, lead author of the publication.   Overall avian species richness didn’t change significantly, but distributions did for many...
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15
Dec

A new partnership is pushing to tally the “blue carbon” in marine and coastal ecosystems.

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,” says Steve Crooks, the lead wetlands and coastal management scientist for Silvestrum Climate Associates, which is one of the organizations working to accelerate the research. “But when you actually get down to the detail of trying to develop market mechanisms...
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15
Dec

A large pulse of water sent through the Yolo Bypass in summer 2016 boosted phytoplankton biomass and food web conditions in Cache Slough and the lower Sacramento River, a new report confirms.

 “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 often negative (meaning they go “upstream”) due to agricultural diversions and low freshwater inflow. Producing the pulse, which increased downstream flows from about negative-two cubic meters per second to a peak of 15 cubic meters per second in the Toe Drain...
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15
Dec

New Way to Sleuth Out Fish IDs in the Field

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 or weeks for lab results,” says Melinda Baerwald, an environmental program manager with the California Department of Water Resources. Traditionally, scientists wishing to verify the identity of a salmon or a smelt had to send samples of fish tissue to...
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