Science news: From salt ponds to salt marsh; New resource published on the structure and function of CA’s ecosystems; Rice fields for salmon fry; DNA evidence shows that salmon hatcheries cause substantial, rapid genetic changes; and more …

SF Bay SatelliteIn science news this week: From salt ponds to salt marsh; New, definitive resource published on the structure and function of California’s ecosystems; Rice fields for salmon fry; DNA evidence shows that salmon hatcheries cause substantial, rapid genetic changes; Reconnected rivers; Common Conquerors: The takeover of the common carp; Pesticide mixtures may increase health risks but are still unregulated by California; Rising seas slowed by increasing water on land; The fate of sediment when freshwater meets saltwater; February 2016 El Niño update: Q & A…and some Thursday-morning quarterbacking; Global impacts of El Niño and La Niña

From salt ponds to salt marsh:  “In the south end of San Francisco Bay, researchers and conservationists are working to restore ancient natural history at the same time as they preserve some more recent history. One decade into this fifty-year challenge, the results are impressive.  Before humans started building settlements and cities along the shores of San Francisco Bay, one of the world’s largest estuaries was surrounded by some of the world’s most extensive wetlands. Tidal marshes around the Bay served as natural water filters, with vegetation and shellfish improving the water quality by drawing out nutrients and algae from the sediment-rich water. They were the nurseries and nesting grounds for hundreds of fish, shellfish, and bird species. These marshes also provided a physical line of defense against storm surges and other weather-induced flooding, as well as rising seas. The landscape was a haven for shorebirds and water fowl, salmon and trout, and seals. … ”  Continue reading at NASA’s Earth Observatory here:  From salt ponds to salt marsh

New, definitive resource published on the structure and function of California’s ecosystems: Ecosystems of California (University of California Press, 2016) is a new comprehensive reference of California’s ecological abundance featuring contributions from 149 experts including 19 with ties to UC Santa Cruz.  Co-edited by Erika Zavaleta, Pepper-Giberson Chair in Environmental Studies at UC Santa Cruz and Harold Mooney, Paul S. and Billie Achilles Professor in Environmental Biology, emeritus, Stanford University, the book examines California’s unique ecosystems through the lenses of past, present, and future.  “It’s about where we’ve come from and how things got to be the way they are,” Zavaleta said. … ”  Read more from Phys Org here:  New, definitive resource published on the structure and function of California’s ecosystems

Rice fields for salmon fry: Any sushi lover will tell you that salmon and rice are an ideal combination.…. Aptly named the Nigiri project, after the fish and rice sushi combo, the experiment has run the last four years in cooperation between the California Departments of Fish and Wildlife and Water Resources, University of California Davis, California Trout, US Bureau of Reclamation and NOAA.  The program is based at the Knaggs Ranch in California’s Yolo County, on the Sacramento River flood plain. ... ”  Read more from Hatchery International here:  Rice fields for salmon fry

DNA evidence shows that salmon hatcheries cause substantial, rapid genetic changes:A new study on steelhead trout in Oregon offers genetic evidence that wild and hatchery fish are different at the DNA level, and that they can become different with surprising speed.  The research, published today in Nature Communications, found that after one generation of hatchery culture, the offspring of wild fish and first-generation differed in the activity of more than 700 genes.  A single generation of adaptation to the hatchery resulted in observable changes at the DNA level that were passed on to offspring, scientists reported. … ”  Read more from Phys Org here:  DNA evidence shows that salmon hatcheries cause substantial, rapid genetic changes

Reconnected rivers:Steelhead can live in the Salinas River watershed, but their ability to access this habitat depends largely on the rain forecast and river water levels. While the main-stem Salinas River is not ideal habitat for adult steelhead spawning, small reaches of suitable habitat exist in Santa Margarita, Nacimiento, and possibly San Antonio rivers in some years, as well as in Estrella Creek. Plentiful, good quality habitat exists in the Arroyo Seco River, but this river sometimes flows underground (see Fish in a Dry Stream), which is a nonstarter for migrating fishing. Thanks to monitoring data we’ve collected at the Salinas River weir, we know that adult steelhead migrate after naturally occurring freshets in river flow produced by heavy rainfall in the Salinas Valley’s drainage basin. Adult steelhead can begin their migration in either the ocean (when there is an opening in the estuary sandbar), in the Salinas River lagoon (fish with an estuary-run life history), or in Elkhorn Slough. Each of these migration origins poses challenges to making the difficult journey upstream to spawn. … ”  Read more from the FishBio blog here:  Reconnected rivers

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Common Conquerors: The takeover of the common carp:  “Some introduced species have managed to become truly global in their reach. One species we are sure to encounter whether working in the waterways of Asia or Central California is the common carp (Cyprinus carpio). This prolific fish has established substantial populations well beyond its native range of Eurasia thanks to a long history of introductions. While not as devastating as other invasive species, many consider common carp a nuisance due to their ability to rapidly reproduce and their voracious omnivorous appetite. As recently as 2014, the common carp has been considered among the top 100 of the world’s worst invaders, and is the third most frequently introduced species worldwide, whether as ornamental pond inhabitants in the form of brightly colored koi, or to supplement fisheries in reservoirs to feed local communities. … ” Read more from the FishBio blog here:  Common Conquerors: The takeover of the common carp

Pesticide mixtures may increase health risks but are still unregulated by California:A UCLA study has found that the state agency responsible for protecting Californians from the dangers of pesticides is failing to assess the health risks likely posed by pesticide mixtures, which are believed to be more harmful than individual pesticides.  The report was published by the Sustainable Technology and Policy Program, which is based in UCLA School of Law and the UCLA Fielding School of Public Health. It recommends the California Department of Pesticide Regulations do more to protect people from the dangers of exposure to multiple pesticides. … ”  Read more from Science Daily here: Pesticide mixtures may increase health risks but are still unregulated by California

Rising seas slowed by increasing water on land: New measurements from a NASA satellite have allowed researchers to identify and quantify, for the first time, how climate-driven increases of liquid water storage on land have affected the rate of sea level rise.  A new study by scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California, and the University of California, Irvine, shows that while ice sheets and glaciers continue to melt, changes in weather and climate over the past decade have caused Earth’s continents to soak up and store an extra 3.2 trillion tons of water in soils, lakes and underground aquifers, temporarily slowing the rate of sea level rise by about 20 percent. … ”  Read more from NASA here:  Rising seas slowed by increasing water on land

The fate of sediment when freshwater meets saltwater: Two recent USGS investigations have measured sedimentation rates along the barely perceptible slope of rivers as they empty into estuaries. The findings of these studies have important implications for the restoration of estuaries — for example, the Chesapeake Bay — and their resilience in the face of sea level rise. The studies compared the sedimentation rates found in upriver tidal freshwater swamps (located at the furthest inland reach of tides) to the rate found in brackish water marshes downstream at the lowest reaches of the rivers. “Sediment trapping in tidal freshwater wetlands is critical for protecting the water quality of estuaries and enhancing the resilience of those wetlands to sea level rise,” said Scott Phillips, USGS science coordinator for the Chesapeake Bay. “These wetlands help reduce nutrients and contaminants from reaching the Bay and also provide critical habitat for waterfowl.”  … ”  Read more from the USGS here:  The fate of sediment when freshwater meets saltwater

How climate change will affect Western groundwater resources: By 2050, climate change will increase the groundwater deficit even more for four economically important aquifers in the Western U.S., reports a University of Arizona-led team of scientists.  The new report is the first to integrate scientists’ knowledge about groundwater in the American West with scientific models that show how climate change will affect the region.  “We wanted to know, ‘What are the expectations for increases and decreases in groundwater as we go forward in this century?'” said lead author Thomas Meixner, a UA professor and associate department head of hydrology and water resources. “In the West, 40 percent of the water comes directly from groundwater.” … ”  Read more from the University of Arizona here:  How climate change will affect Western groundwater resources

February 2016 El Niño update: Q & A…and some Thursday-morning quarterbacking: Despite getting a little boost from some strong winds across the tropical Pacific Ocean in January, the warmer-than-average ocean temperatures that drive El Niño have likely peaked. Now that we’re looking out from the other side of the mountain, let’s answer some questions.  So is this the strongest El Niño on record, or what?  This is definitely one of the strongest three going back to 1950.  It’s hard to say definitively what single El Niño is the strongest, because there are a lot of different ways to measure strength. … ”  Read more from the ENSO blog here: February 2016 El Niño update: Q & A…and some Thursday-morning quarterbacking

Global impacts of El Niño and La Niña:El Niño and La Niña are the opposite phases of ENSO (pronounced en-so), which is short for El Niño-Southern Oscillation. Operating in the tropical Pacific Ocean, ENSO is Earth’s singlest most influential natural climate pattern.  El Niño and La Niña alternately warm and cool large areas of the tropical Pacific—the world’s largest ocean—which significantly influences where and how much it rains there. The primary location of moist, rising air (over the basin’s warmest water) is centered over the central or eastern Pacific during El Niño and over Indonesia and the western Pacific during La Niña. … ”  Read more from Climate.gov here:  Global impacts of El Niño and La Niña

Maven’s XKCD Comic Pick of the Week …

 

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About Science News and Reports: This weekly feature, posted every Thursday, is a collection of the latest scientific research and reports with a focus on relevant issues to the Delta and to California water, although other issues such as climate change are sometimes included. Do you have an item to be included here? Submissions of relevant research and other materials is welcome. Email Maven

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