Christmas tree worms; Photo by NOAA

SCIENCE NEWS: Dredging up the past at Antioch Dunes; Encountering an alien on a Point Reyes beach; Kokanee salmon egg collection; Methane in tidal marshes; and more …

Dredging up the past at Antioch Dunes

Over thousands of years, the shifting sands of time built dunes that reached 120 feet high and stretched for 2 miles along the San Joaquin River, about 35 miles east of San Francisco. Isolated from similar habitats, the Antioch Dunes slowly developed species found nowhere else in the world.  The gradual shifting of sand, however, was replaced by a rapid effort to turn it into bricks in 1906, after a devastating earthquake and fires demolished buildings in San Francisco. As industry depleted the sand over the next 70 years, the dunes’ unique species struggled to survive on dunes that eventually topped out at 50 feet. … ”  Read more from the US FWS here:  Dredging up the past at Antioch Dunes

Encountering an alien on a Point Reyes beach

I’ve walked along Limantour Beach in the Point Reyes National Seashore dozens of times over the years, but never seen anything like the small jelly pods I found scattered in the sand along the tidal line on a walk this fall. Clear, translucent, and the size of a thumb, I suspected they were jellyfish that had washed up with the tide — but a closer look revealed something far more unusual.  Holding one in my hand, I could see that it was hollow inside, with an even smaller creature curled up in the cavity. It looked clear, matching the jelly pod around it, but also somewhat like a crustacean. I thought of a shrimp, but that didn’t quite match. And then, as I puzzled over it, the mystery creature reached out of the pod with a tiny little arm and an even more miniscule pincher at the end, not unlike a lobster claw. With four eyes looking back at me from a translucent, bulbous head, it looked like an alien from a movie set. ... ”  Read more from Bay Nature here: Encountering an alien on a Point Reyes beach

Spotlight: Kokanee salmon egg collection from Stampede Reservoir

In spite of challenges presented by wildfires, forest closures, unhealthy air quality and the COVID-19 pandemic, CDFW staff from the American River Trout Hatchery and Fisheries Branch nonetheless conducted four successful kokanee salmon egg collections on the Little Truckee River this fall.  Slightly more than 1.3 million eggs were collected from kokanee salmon migrating from Stampede Reservoir in Nevada County into the Little Truckee River to spawn. Stampede Reservoir’s kokanee salmon serve as CDFW’s broodstock for the popular State fishery. … ”  Read more from the Department of Fish and Wildlife here: Spotlight: Kokanee salmon egg collection from Stampede Reservoir

Error correction means California’s future wetter winters may never come

California and other areas of the U.S. Southwest may see less future winter precipitation than previously projected by climate models. After probing a persistent error in widely used models, researchers at the Department of Energy’s Pacific Northwest National Laboratory estimate that California will likely experience drier winters in the future than projected by some climate models, meaning residents may see less spring runoff, higher spring temperatures, and an increased risk of wildfire in coming years. … ”  Read more from Pacific Northwest National Labs here:  Error correction means California’s future wetter winters may never come

A Well-Rooted Study: Remote sensing an effective way to monitor groundwater along river corridors in the Southwest

Spend time in any of the world’s great forests and you’ll start seeing the trees as immense pillars holding the heavens aloft while firmly anchored in the earth. It’s as much fact as sentiment. Trees really do link the ground to the sky by exchanging energy and matter between the soil and the atmosphere. Researchers believe that understanding this connection could provide both a wealth of scientific insight into ecosystems and practical applications that address challenges such as water resource conservation and management. … ”  Read more from UC Santa Barbara here:  A Well-Rooted Study: Remote sensing an effective way to monitor groundwater along river corridors in the Southwest

Dirty trees shape earth’s hydrologic and carbon cycles

As rain falls on forest canopies, its journey begins. As raindrops reach Earth, they ferry creatures and contaminants to soils and streams below. Researchers have only recently begun to explore the fine details of this journey, as evidenced by a session on “Precipitation Partitioning by Vegetation” at AGU’s virtual Fall Meeting 2020.  When a raindrop falls over land, it might bounce off leaves or slide down tree trunks before reaching the ground. Depending on where it lands, that drop will eventually contribute to a river, be absorbed into a forest floor, or evaporate back into the atmosphere. This distribution of precipitation by trees and shrubs is often the first step in the terrestrial hydrologic cycle, yet fundamental data on its consequences remain relatively sparse.  “We tend to ignore canopies as an interface for water to reach the Earth’s surface,” said John Van Stan, an ecohydrologist at Georgia Southern University. “But they connect to so many aspects of an ecosystem. They’re the first thing that controls where water goes.” … ”  Read more from EOS here: Dirty trees shape earth’s hydrologic and carbon cycles

Alaska’s salmon are shrinking

A fisheries ecologist at the University of Alaska Fairbanks, Krista Oke has heard it time and again from fishermen up and down Alaska rivers: Salmon just aren’t as big as they used to be. This is especially true on the Yukon River, she says, where Chinook salmon is a cultural touchstone and staple food for Indigenous people in both the US and Canada.  In recent decades, rising river temperatures in the Yukon watershed have ushered in a steady decline in Chinook abundance. Now, researchers have confirmed that these fish are significantly smaller as well. “You have fewer fish coming back, and each of them is smaller,” says Oke. “There could be really important consequences of these changes.” … ”  Read more from Earth Island Journal here: Alaska’s salmon are shrinking

Methane in tidal marshes

A pair of University of Delaware researchers were studying “blue carbon” — the carbon stored in coastal ecosystems such as mangrove forests, salt marshes or sea grasses — when they found something no one expected to see in a salt marsh: large quantities of methane in the soil.  Angelia Seyfferth and Rodrigo Vargas of the Department of Plant and Soil Sciences in UD’s College of Agriculture and Natural Resources were leading different projects in a salt marsh and observed — from different angles — a previously unrecognized potential source of methane, an important greenhouse gas. … ”  Read more from Water Online here:  Methane in tidal marshes

Fish carcasses deliver toxic mercury pollution to the deepest ocean trenches

The sinking carcasses of fish from near-surface waters deliver toxic mercury pollution to the most remote and inaccessible parts of the world’s oceans, including the deepest spot of them all: the 36,000-foot-deep Mariana Trench in the northwest Pacific.  And most of that mercury began its long journey to the deep-sea trenches as atmospheric emissions from coal-fired power plants, mining operations, cement factories, incinerators and other human activities. … ”  Read more from Water Online here: Fish carcasses deliver toxic mercury pollution to the deepest ocean trenches

Urban land and aerosols amplify hazardous weather, steer storms toward cities

Urban landscapes and human-made aerosols—particles suspended in the atmosphere—have the potential to not only make gusts stronger and hail larger; they can also start storms sooner and even pull them toward cities, according to new research exploring the impact of urban development on hazardous weather, led by scientists at the U.S. Department of Energy’s Pacific Northwest National Laboratory.   By modeling two thunderstorms—one near Houston, Texas, and another in Kansas City, Mo.—atmospheric scientist Jiwen Fan teased out the separate and synergistic effects that urban landscapes and human-caused aerosols can have on storms, rain and hail. … ”  Read more from Pacific Northwest National Labs here: Urban land and aerosols amplify hazardous weather, steer storms toward cities

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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