SCIENCE NEWS: Report: Restoring Franks Tract; ‘River Jedi’; The salmon struggle for survival out of the San Joaquin River; New model of Chinook salmon populations better accounts for errors; New NOAA Fisheries plan adopts ecosystem management principles; and more …

In science news this week:

Report: Restoring Franks Tract:  “In the heart of California’s Sacramento-San Joaquin River Delta lies a 3,000-acre flooded island called Franks Tract.  Before humans diked and drained Franks Tract to grow potatoes, grains, asparagus and corn, the island was part of a vast freshwater marsh. Breaches in levees flooded Franks Tract in 1937, and farmers never reclaimed the island. Franks Tract today is a nexus point of many delta uses, ranging from duck hunting and bass fishing to fresh water supply for California cities and farms.  But the island is also a hot spot for invasive plants and predatory fishes, as well as a conduit for saltwater intrusion into waterways used to convey freshwater supplies to cities and agriculture in the Delta and other parts of California. For these reasons, Franks Tract is considered a strong candidate for partial restoration. … ”  Read more from the Department of Fish and Wildlife here:  Report: Restoring Franks Tract

‘River Jedi’: Red Bluff Fish & Wildlife Office biologists break new ground in Sacramento River juvenile green sturgeon migration research: “On a cold, dark, moonless night last December, the U.S. Fish and Wildlife boat stealthily cruised along the upper Sacramento River near Corning, California on its nightly mission to find green sturgeon.  Except for the sound of the boat engine signaling a change of location, and an occasional coyote howl heard off in the distance, most of the four-hour trip on this frigid night took place in workmanlike silence.  Even now, in June and amidst the scorching heat of another northern California summer, the chill of that winter evening remains fresh, as the crew diligently worked its unique assignment: a regular winter nighttime fish survey.  “Nighttime trawls are really rare,” said crew chief Chad Praetorius. “You have to know the river and where you’re going. You basically have to be a River Jedi.” ... ”  Read more from the US Fish and Wildlife Service here:  ‘River Jedi’: Red Bluff Fish & Wildlife Office biologists break new ground in Sacramento River juvenile green sturgeon migration research

The salmon struggle for survival out of the San Joaquin River:  “Much like old-timer tales of walking to school uphill both ways, it can seem like Chinook salmon in the Central Valley have to swim uphill both ways when migrating to and from the ocean. It’s no secret that young salmon and steelhead face a formidable obstacle course when trying to exit the Sacramento-San Joaquin River Delta toward the Pacific Ocean. A maze of natural and man-made stream channels, dead-end sloughs, predators, rip-rap-lined channels cut off from floodplains, and pumps that reverse the flow of rivers all confuse, consume, and strand juvenile salmon. Researchers and managers have long known survival is particularly low for young salmon migrating through the San Joaquin River and South Delta. However, a study published earlier this year in the North American Journal of Fisheries Management shows just how low it can be: in some years, survival is estimated to be zero – meaning no juvenile salmon from the San Joaquin River make it to the ocean (Buchanan et al. 2018).  ... ”  Read more from FishBio here:  The salmon struggle for survival out of the San Joaquin River

Site of the next major earthquake on the San Andreas fault?  “Many researchers hypothesize that the southern tip of the 1300-km-long San Andreas fault zone (SAFZ) could be the nucleation site of the next major earthquake on the fault, yet geoscientists cannot evaluate this hazard until the location and geometry of the fault zone is documented.  In their new paper for Lithosphere, Susanne Jänecke and colleagues use detailed geologic and structural mapping of the southern 30 km of the San Andreas fault zone in southern California to show that it is a highly faulted volume of rock that is 1-4 km wide and organized as a sheared ladder-like structure in the upper 3-5 kilometers of the earth. ... ”  Read more from Science Daily here:  Site of the next major earthquake on the San Andreas fault?

Less error, better forecasts: A new model of Chinook salmon populations better accounts for human and environmental error: A new NOAA technical memorandum describes a statistical framework for modeling population changes in Chinook salmon in the Columbia and Snake Rivers. Known as an integrated population model, the framework provides a way for fish biologists, managers, and industry to make better-informed decisions about fisheries management by providing more accurate estimates of future populations and their risks of extinction. The framework is more comprehensive and accurate because it better accounts for error. Traditional models don’t explicitly distinguish between process and observation error. ... ”  Read more from the Northwest Fisheries Science Center here: Less error, better forecasts: A new model of Chinook salmon populations better accounts for human and environmental error

New NOAA Fisheries plan adopts ecosystem management principles: “NOAA Fisheries’ West Coast Region, with its Southwest Fisheries Science Center in La Jolla, Calif., and Northwest Fisheries Science Center in Seattle, have released a new blueprint for how the agency will put ecosystem-based management principles into practice on the West Coast.  The draft Western Roadmap Implementation Plan (WRIP), tiered off NOAA Fisheries’ national Ecosystem Based Fisheries Management Policy and Roadmap, offers a distinctly different way of thinking about fisheries in the California Current Ecosystem. Instead of considering and managing species in isolation, fisheries managers will weigh the role of species in an ecosystem when making decisions. … ”  Read more from NOAA here:  New NOAA Fisheries plan adopts ecosystem management principles

Politically leaning influences city water policies as strongly as climate:  “Urban water conservation policies are reflecting the nation’s political polarization, with a new report demonstrating that a city’s water ordinances can be as much related to whether it leans left or right as to whether the climate is wet or dry.  Vanderbilt University environmental researchers found Los Angeles ranks No. 1 for number and strength of policies, followed by six other left-leaning California cities along with Austin, Texas. It takes until San Antonio, Texas, at No. 8 to find a right-leaning city with strong water conservation policies — probably because the amount of water it can withdraw from the Edwards Aquifer is strictly limited, said the study’s lead author, Jonathan Gilligan, associate professor of earth and environmental sciences. … ”  Read more from Science Daily here:  Politically leaning influences city water policies as strongly as climate

Dry riverbeds are contributing to climate change more than previously thought:  “A massive world-wide study of dry riverbeds has found they’re contributing more carbon emissions than previously thought, and this could help scientists better understand how to fight climate change.  Dr Nathan Waltham from the Tropical Water and Aquatic Eco-systems Research Centre (TropWATER) and James Cook University in Australia, joined scientists from 22 other countries who looked at 212 dry riverbeds on every continent on earth.  He said the contribution of intermittent rivers and streams to the process of carbon cycling — the process by which carbon is circulated around the ecosystem — is largely ignored. … ”  Read more from Science Daily here:  Dry riverbeds are contributing to climate change more than previously thought

Climate change has fish moving faster than regulations can keep up:  “The world’s system for allocating fish stocks is being outpaced by the movement of fish species in response to climate change, according to a study undertaken by an international team of marine ecologists, fisheries and social scientists, and lawyers.  “Fish fleeing warming waters will cross national boundaries and add new ‘shareholders’ to existing fisheries,” said senior author William Cheung, associate professor in UBC’s Institute for the Oceans and Fisheries and director of science for the Nippon Foundation-UBC Nereus Program, which helped fund the research. “Without a pre-agreed mechanism to accommodate these unexpected fish shareholders, we could witness more international disputes over the allocation of fisheries resources.” … ”  Read more from Science Daily here:  Climate change has fish moving faster than regulations can keep up

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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