SCIENCE NEWS: Assessing portfolios of actions for winter-run salmon in the Sacramento Valley; Reading the bones: ancient chinook salmon DNA challenges modern assumptions; Salt marshes trap microplastics in their sediments; and more …

Assessing portfolios of actions for winter-run salmon in the Sacramento Valley

We may be entering a time when more mechanistic understanding can be used to estimate effects of habitats and flows on fish populations and health, and help design ecosystem restoration efforts.  An integrated portfolio approach to protecting and restoring winter-run salmon would begin with a model estimating the effectiveness of a set of restoration actions on juvenile salmon out-migrating populations. The recently-published Winter-Run Habitat-based Population model (WRHAP) does just this.  A summary of this model is presented in this blog and the accompanying video. … ”  Read more from the California Water Blog here:  Assessing portfolios of actions for winter-run salmon in the Sacramento Valley

Reading the bones: ancient chinook salmon DNA challenges modern assumptions

Knowing the historic range of an imperiled species, prior to human disturbance, is critical information for population recovery actions. Historic accounts and museum collections help scientists piece together where species occurred in the past, but even these resources may represent a shifted baseline, or a time when populations were already being affected by human activities. This can lead to debate over official range maps, which play a large role in guiding management. One such debate has arisen about the tributaries of the San Francisco Bay. Although Chinook salmon (Oncorhynchus tshawytscha) currently spawn in these watersheds, they are officially regarded as non-native. However, a recent analysis of archaeological samples from a Native American midden in the city of Santa Clara dating back more than 200 years has provided evidence that the Chinook range may have in fact extended to the southern end of San Francisco Bay (Lanman et al. 2021). This study demonstrates the potential power of ancient DNA (aDNA) analysis combined with archaeological specimens to reexamine preconceived notions about even the most intensively studied species. … ”  Read more from Fish Bio here: Reading the bones: ancient chinook salmon DNA challenges modern assumptions

New challenges and historical insights – salmon science at the 2021 Bay Delta conference

The recent 2021 Bay Delta Science Conference included a session specifically dedicated to salmonid research in California’s Central Valley, which provided an update on recent studies related to Chinook salmon (Oncorhynchus tshawytshaw) and steelhead (O. mykiss). The presentations revealed that even with extensively studied species like salmon, researchers are continually achieving new insights that can help improve tools for monitoring, management, and recovery. The session began with a presentation by NOAA scientist Rachel Johnson, who described the response to thiamine (vitamin B1) deficiencies in Chinook salmon. In 2020, these deficiencies caused reproductive failure in spring, fall, and late-fall runs, leading to concerns of a similar impact to winter-run, and prompting the creation of a thiamine research team to investigate impacts and potential mitigation strategies.  … ”  Continue reading at FishBio here: New challenges and historical insights – salmon science at the 2021 Bay Delta conference

Owens Pupfish Given New Chance

A species of fish once declared extinct has not only survived but is expected to thrive thanks to a five-year effort to restore habitat and translocate more than 700 Owens pupfish.  In early April biologists from the California Department of Fish and Wildlife (CDFW) and U.S. Fish and Wildlife Service, Reno Office (USFWS) moved the pupfish from five different habitats in the Owens Valley to the River Spring Lakes Ecological Reserve in Mono County. These fish, once surviving in under an acre of habitat, now have several square miles of marsh to live in. Prior to the translocation, CDFW completed the removal of non-native fish from the reserve to ensure the future of the pupfish. ... ”  Read more from the Department of Fish and Wildlife here: Owens Pupfish Given New Chance

DISB REPORT: The Science of Non-native Species in a Dynamic Delta

The Delta Independent Science Board (Delta ISB), which provides scientific oversight of programs that support adaptive management, has finished its review on the science of non-native species in the Sacramento-San Joaquin Delta (Delta).  The review highlights the importance of anticipation – getting ahead of non-native species invasions for prevention and mitigation – as non-native species threaten Delta ecosystem services and the ability to protect, restore, enhance, and define the Delta ecosystem. The Delta ISB encourages a more ecosystem-level, forward-looking, integrated approach to non-native species science in the Delta with specific consideration of climate change. The review offers seven specific recommendations.”  Click here for the DISB report.

New ‘Swiss Army knife’ cleans up water pollution

Phosphate pollution in rivers, lakes and other waterways has reached dangerous levels, causing algae blooms that starve fish and aquatic plants of oxygen. Meanwhile, farmers worldwide are coming to terms with a dwindling reserve of phosphate fertilizers that feed half the world’s food supply.  Inspired by Chicago’s many nearby bodies of water, a Northwestern University-led team has developed a way to repeatedly remove and reuse phosphate from polluted waters. The researchers liken the development to a “Swiss Army knife” for pollution remediation as they tailor their membrane to absorb and later release other pollutants. ... ”  Read more from Northwestern University here: New ‘Swiss Army knife’ cleans up water pollution

Salt marshes trap microplastics in their sediments, creating record of human plastic use

Plastics are everywhere. From cell phones to pens and cars to medical devices, the modern world is full of plastic— and plastic waste. New research from scientists at the Marine Biological Laboratory (MBL) Ecosystems Center found that some of that plastic waste has been accumulating in salt marshes for decades. The study was published in Environmental Advances.  Salt marshes are the link between the land and open ocean ecosystems, and — in a way —between urban environments and the wild ocean. Microplastics (plastic particles smaller than 5 millimeters) tend to float on the water surface, but salt marshes fill and empty with the tides, so particles that would normally float get trapped within branches and roots and settle into the marsh soil. ... ”  Read more from the Marine Biological Laboratory here: Salt marshes trap microplastics in their sediments, creating record of human plastic use

What happens after dam removals

Maine’s Penobscot River has more than 100 dams, many of which are aging and no longer serve their original purpose. Removing dams is becoming more common, with the purposes of addressing hazards posed by these aging dams, returning natural river flow and function, or both.  For Atlantic salmon and other species of sea-run fish, the last 200 years of dammed rivers and disconnected streams have, combined with historic fisheries and lower marine survival, spelled decline, and for Atlantic salmon, disaster. The storied Atlantic salmon runs had fish returning in the thousands to Northeast rivers. They are now limited to just a few rivers in Maine, with fewer than 2,000 fish returning each year. These runs are heavily reliant on hatchery-raised fish. The Penobscot River is home to the largest remaining population of endangered Atlantic salmon in the United States. Dams have been identified as one of the primary factors in the decline of Atlantic salmon. … ”  Continue reading at NOAA Fisheries here: What happens after dam removals

From radioactive rain to hitchhiking tardigrades, particulates in precipitation have big implications for ecosystems

A single raindrop may seem insignificant to the human eye, but a closer look will reveal a diverse community of organisms and non-living materials that could have major implications for understanding how ecosystems work, according to a new research paper from University of North Texas ecosystem geographer Alexandra Ponette-González.  “Every little rain or fog droplet is a world of its own containing potentially beneficial or harmful things for ecosystems,” said Ponette-González, an associate professor in the College of Liberal Arts and Social Sciences Department of Geography and the Environment. “The nature and composition of that droplet changes as it moves through the plant canopy.”  Ponette-González, along with research collaborators at Georgia Southern University and the Cary Institute of Ecosystem Studies, shines a magnifying glass on the microscopic materials that land on and flow through plants with water in a paper published in Frontiers in Ecology and the Environment, the Ecological Society of America’s flagship journal. … ”  Continue reading at the University of Texas here: From radioactive rain to hitchhiking tardigrades, particulates in precipitation have big implications for ecosystems

Coastal flooding increases Bay Area traffic delays and accidents

Almost half of the world’s population currently lives in cities and that number is projected to rise significantly in the near future. This rapid urbanization is contributing to increased flood risk due to the growing concentration of people and resources in cities and the clustering of cities along coastlines.  These urban shifts also result in more complex and interconnected systems on which people depend, such as transportation networks. Disruptions to urban traffic networks from flooding or other natural disasters can have serious socioeconomic consequences. In fact, what are defined as indirect impacts from these types of events, such as commute-related employee absences, travel time delays and increase in vehicular accident rates, could ultimately outweigh the more direct physical damage to roads and infrastructure caused by severe flooding. … ”  Read more from Stanford University here: Coastal flooding increases Bay Area traffic delays and accidents

President Biden’s Fiscal Year 2022 budget makes significant investments in USGS initiatives

The Biden-Harris administration today submitted to Congress the President’s budget for fiscal year 2022, including $1.6 billion in proposed funding for the U.S. Geological Survey, an increase of $326.9 million or 25 percent above the 2021 enacted level. This proposal would fund investments to unleash science and combat climate change while laying the foundation for economic growth, creating good-paying jobs and ensuring that those benefits accrue to marginalized and overburdened communities.  “The Interior Department plays an important role in the President’s plan to reinvest in the American people. From bolstering climate resiliency and increasing renewable energy, to supporting Tribal nations and advancing environmental justice, President Biden’s budget will make much-needed investments in communities and projects that will advance our vision for a robust and equitable clean energy future,” said Secretary Deb Haaland. … “Read more from the USGS here:  President Biden’s Fiscal Year 2022 budget makes significant investments in USGS initiatives

Featured image: NASA JPL image of the Delta

The Sacramento-San Joaquin River Delta, CA (or California Delta) has an area of about 3000 km2, and provides a large fraction of all the water used in California. The Delta drains about 50&percnt of the water coming from the Sierra Nevada Mountains, and channels it through San Francisco’s Golden Gate to the Pacific Ocean. Thousands of miles of levees now carefully control the Delta’s flow, to maximize water use. The image combines a false color infrared composite (with vegetation depicted in red) with a colorized thermal infrared band to show the water temperature for the larger water bodies. Warmer temperatures are red and yellow, cooler water temperatures are blue and green. The image was acquired July 3, 2012, covers an area of 46.5 by 57.5 km, and is located at 38.1 degrees north, 121.3 degrees west. … ”  Read more from NASA JPL here:  NASA JPL image of the Delta (above)

Maven’s XKCD Comic Pick of the Week …



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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