Researchers probe deaths of Central Valley chinook, with possible ties to ocean changes

Scientists from several fish and wildlife agencies have launched a rapid research and response effort for deficiency of thiamine, or Vitamin B1. This deficiency was recently found to be increasing juvenile mortality among Chinook salmon in California’s Central Valley.  The magnitude of its effect is not clear. However, it could be a risk to Chinook stocks, including endangered winter-run Chinook salmon and the fishery for fall-run Chinook salmon.  In early 2020, staff at state and federal salmon hatcheries in California’s Central Valley observed newly hatched offspring of adult Chinook salmon that spawned in 2019. They were swimming in corkscrew patterns and dying at unusually high rates. Researchers at the U.S. Fish and Wildlife Service’s California-Nevada Fish Health Center eliminated infectious diseases as the cause. Then, they noticed that a bath of thiamine immediately revived the ailing juveniles. … ”  Read more from NOAA here:  Researchers probe deaths of Central Valley chinook, with possible ties to ocean changes

Spring-run and fall-run Chinook salmon aren’t as different as they seem

Historically, spring-run and fall-run Chinook salmon have been considered as separate subspecies, races, ecotypes, or even as separate species of fish. A new genetic analysis, however, shows that the timing of migration in Chinook salmon is determined entirely by differences in one short stretch of DNA in their genomes.  The new findings, published October 29 in Science, mean that within a drainage basin like the Klamath River, the different runs of Chinook salmon are all part of a single diverse population. … ”  Read more from UC Santa Cruz here:  Spring-run and fall-run Chinook salmon aren’t as different as they seem

Ancient lake contributed to past San Andreas fault ruptures

The San Andreas fault, which runs along the western coast of North America and crosses dense population centers like Los Angeles, California, is one of the most-studied faults in North America because of its significant hazard risk. Based on its roughly 150-year recurrence interval for magnitude 7.5 earthquakes and the fact that it’s been over 300 years since that’s happened, the southern San Andreas fault has long been called ‘overdue’ for such an earthquake. … ”  Read more from Science Daily here:  Ancient lake contributed to past San Andreas fault ruptures

Invasion of the water body snatchers: Managing aquatic invasive species

Invasive species can be sneaky, moving like non-native ninjas into an ecosystem and wreaking havoc before anyone notices they’re there. This is particularly true of aquatic plants and animals hidden beneath the water’s surface. However, this threat is beginning to get the attention it deserves. Effective methods for managing invaders from the terrestrial world are being applied to aquatic settings, and new technologies are yielding exciting possibilities to deploy. Learning from successes and mistakes of past endeavours is critical to improving the anti-invasive toolkit. To that end, a review published in Hydrobiologia chronicles the battles won and lost against freshwater and marine invasive species, considers the effectiveness of various approaches to control or eradicate these pests, and discusses cutting-edge innovations (Simberloff 2020). From gene-silencing to hunter-killer robots, the road ahead is laden with remarkable new tools to manage and eliminate aquatic invasives, but the risks of such methods will be increasingly important to consider. … ”  Read more from FishBio here: Invasion of the water body snatchers: Managing aquatic invasive species

Iconic trout can access historic spawning grounds

Just one year after celebrating the Derby Dam groundbreaking ceremony, the state-of-the-art fish screen is ready and waiting to help Lahontan cutthroat trout travel from Pyramid lake to their spawning grounds above the dam.  “The U.S. Fish and Wildlife Service is thrilled to finally have the Derby Dam fish screen completed,” said Service California Great Basin regional director Paul Souza. “The addition of this fish screen to the existing water infrastructure will allow the iconic Lahontan cutthroat trout to once again travel beyond the dam and complete its natural migration route for the first time in more than a century. … ”  Read more from the US FWS here: Iconic trout can access historic spawning grounds

Microplastics induce changes in mussel traits and behaviors

When microplastics release chemicals in seawater, mussels may react by subduing or ramping up traits and behaviors that influence their ability to form mussel beds, says a paper recently published in the Ecological Society of America’s journal Ecological Applications.   The authors staked out mussel collection sites on the coasts of France and South Africa, and painstakingly counted microplastic particles on the sand when waters receded during low tide. They found high densities of microplastics, reporting as many as 950 microplastic particles per square meter at some sites. … ”  Read more from ESA here:  Microplastics induce changes in mussel traits and behaviors

Scientists dug through 5,000 years of penguin poo and found a chilling warning

Seabird poop, or guano, has the power to nourish ecosystems, is worth millions of dollars, and leave a visual impression that can be seen from space.  Now, scientists have scoured 14,000 years of poop from penguins, petrels, and shearwaters, preserved in the peatlands of the Falkland Islands, according to a study published on Friday in Science Advances. The idea was to gain insight into the possible correlations between climate changes and seabird ranges, as well as to assess the long-term effect of the birds on the land habitat. … ”  Read more from Sci Tech Daily here: Scientists dug through 5,000 years of penguin poo and found a chilling warning

First-of-its-kind surface water Atlas brings together 35 years of satellite data

The Atlas of Global Surface Water Dynamics created by the European Commission’s Joint Research Center (JRC) illustrates the changes in the Earth’s lakes, rivers and wetlands over time. The atlas provides a better understanding of the consequences climate change and human actions have for the planet’s surface water resources. … Building on a project that combined thousands of years of computer time with millions of satellite images, the JRC’s Atlas of Global Surface Water Dynamics describes the important role that surface water plays for our planet’s climate and biodiversity, as well as virtually every aspect of our daily lives. … ”  Read more from Phys Org here:  First-of-its-kind surface water Atlas brings together 35 years of satellite data

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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