Reflowing the Sierra to the Sea

Reflowing the Sierra to the Sea

A fall flight over the Mexican coast where the Colorado River meets the Sea of Cortez offered me a gut-punching, eye-screwing, visual on the results of impaired flow. The semantics of ‘unimpaired’ and ‘impaired’ flow have laced the language of California water management debates since some engineer invented these politically ‘neutral’ terms long ago. The terms refer to our alteration of freshwater flows from snowmelt and runoff by dams and diversions. But whatever the labels, or whichever estuary you’re referring...
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Sleuthing Sturgeon Snags

Local green sturgeon are struggling. The population that spawns in the Sacramento –San Joaquin River Delta was declared federally threatened in 2006. Researchers at UC Davis, which hosts the world’s only green sturgeon rearing program, are now trying to figure out why the fish is in trouble. “If we knew how large they are when they’re moving through each portion of the system, we’d know a lot more about the threats they face at each life state, and where we...
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Hauling Out on Higher Ground

Harbor Seals “have this dual existence,” says Sarah Allen, National Park Service ecologist. “They’re tied to the land physiologically and tied to the bay waters for food and travel.” From rocky islets to tidal marshes, the Bay shoreline offers respite to these native marine mammals. Rocky islets like the Castro Rocks, located near the Richmond-San Rafael Bridge, are particularly important refuges -- but more than half the islets that exist throughout the Bay are likely to be erased by sea-level...
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Shark Hunt Stand Off

In the spring and summer months, anglers armed with heavy line and large hooks drop anchor in the murky, current-torn waters between Alcatraz and the Golden Gate Bridge seeking the elusive, and occasionally gigantic, broadnose sevengill shark. As social-media hype stokes excitement among trophy seekers, some other fisherfolk and conservationists want to see the pursuit ended before it depletes shark numbers. While interest in catching large, breeding-age sevelgills has risen in recent years, it remains unclear whether the population can...
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Incidental findings of a long-term study of brown bear predation on salmon have revealed a hidden link between the fish and forest health.

For 20 years, Tom Quinn, a professor in Aquatic and Fishery Sciences at the University of Washington, waded in southwestern Alaska’s Hansen Creek with his students, counting and measuring sockeye salmon carcasses in the stream. Quinn asked his students to toss the bodies on the north bank of the creek to avoid double counting; over the years, they tossed close to 295 tons of salmon onto the north bank. In 2016, Quinn and his colleagues and students took core samples...
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Floods and droughts can cause pools and riffles—and the bugs that live in them—to become more homogenous.

For years, scientists monitoring water quality in streams and rivers have collected mixed samples of aquatic invertebrates from riffles, pools, and transition zones. But UC Santa Barbara stream ecologist David Herbst and his colleagues recently finished a 15-year study of the benthic life in small streams of the central Sierra that examined pools and riffles separately. They found that during flood and drought events, these habitats and their inhabitants become more uniform. But while floods come and go, droughts can...
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MEGA-PEARLS, Oct 2018

A Stream of Science Takeaways. ESTUARY News sent reporters to the biennial Bay-Delta Science Conference in September. This special edition of Pearls shares more than 20 takeaways.
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Spring-run Salmon Need More Than Simple Answers

The number one item still found in California’s beach and coast clean ups is cigarette butts, according to Surfrider’s San Francisco chapter director Shelley Ericksen. Surfrider’s “Hold-on-to-your-Butt” campaign, launched in 1992, and local law enforcement have failed to make a dent in the habit of smokers tossing their butts anywhere they please, and this isn’t good for the environment. A 2011 study in the journal Tobacco Control showed that a single butt in a liter of water can lethally poison...
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Following the Water: Bobcats in Coyote Valley

By Ashleigh Papp From a bird’s eye view, the area between the Santa Cruz and Diablo mountain ranges looks like any typical valley. But the work being done by Tanya Diamond, a wildlife biologist with Pathways for Wildlife, shows that the Coyote Valley offers much more to native wildlife and conservationists than mere open space. With satellite tracking collars and footage captured by hidden cameras, Diamond’s team has confirmed just how much water – Coyote and Fisher Creeks in particular...
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Kitchen Sink Update on Every Last Invader

On multiple fronts, with multiple forces and weapons, California’s battle against invasive aquatic organisms continues. Notoriously, San Francisco Bay is the world’s most invaded estuary. The state’s lakes, rivers, and other freshwater wetlands have their own problematic exotics. Keeping them out, and preventing their spread once established, requires coordination among agencies and levels of government. At best, meshing jurisdictional gears can be a challenge. Legislation pending in Congress could make treating ships’ ballast water to remove invasives yet another source...
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Help may be on the way for critically endangered southern resident killer whales.

NOAA Fisheries and the Washington Department of Fish and Wildlife have partnered to produce a list of the west coast Chinook salmon stocks most important to the whale’s survival. This list comes as a part of a special action plan by NOAA to address the three primary threats to the southern resident killer whales: Chemical contaminants, vessel traffic, and lack of prey. The salmon, themselves endangered, are the preferred food source for the whales, and identifying the salmon runs—which include...
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Nighttime lights on bridges shining into bays and rivers can attract and confuse fish as they migrate at night, leaving them vulnerable to predation.

“Well-lighted bridges and dams can create twilight conditions that predators love, especially other fish,” says Peter Moyle, professor emeritus at UC Davis. He recounts that at one point the Red Bluff Diversion Dam was lit up at night and pikeminnow took the opportunity to prey on juvenile salmon. “Opening up the gates helped because the pikeminnow were headed upstream to spawn so didn’t really want to be there, and the juvenile salmon could move past the dam quickly at night.”...
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California sea lion nurseries are moving north as Año Nuevo Island and the southeast Farallon Islands experience a record-breaking boom in sea lion births.

Zalophus californianus have traditionally preferred nurseries in the Channel Islands, but the population of pups born off Northern California’s coast began skyrocketing in 2016. Births at both sites went from a few dozen pups to more than 500. The trend has only intensified since; more than a thousand pups born at the Farallones, and between 500 and 700 at Año Nuevo, in 2017 according to NOAA; similar numbers are expected this year, although final counts are not yet available. Such...
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The latest casualty in America’s opioid epidemic is a small invertebrate that filters pollutants and feeds hungry shorebirds.

Biologists testing mussels in the waters around Seattle as part of the Puget Sound Mussel Monitoring Program found oxycodone in mussel tissue for the first time, along with antibiotics, antidepressants, chemotherapy drugs, and heart medications. “We have found evidence that these chemicals are in our nearshore marine waters and are being taken up by marine biota living there,” said Washington Department of Fish & Wildlife biologist Jennifer Lanksbury. She also tested juvenile Chinook salmon in Puget Sound estuaries and found...
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Hopeful Outlook for Pacific Herring

Cold water, essential for the life cycle of Chinook salmon, is all too often in short supply along the Sacramento River. A primary cause: California’s massive water conveyance system, using reservoirs, dams, and hydroelectric plants to divert water and deliver power to farms and cities. “When we started releasing water in spring, we let cold water out too early. None was left by fall, when salmon really needed it,” says USBR hydraulic engineer Tracy Vermeyen. Two clever innovations have been...
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A wide-ranging Habitat Conservation Plan that could eventually protect up to 4800 acres of endangered species habitat in the Bay Area is the linchpin of a November agreement between the U.S. Fish and Wildlife Service and Pacific Gas and Electric Company.

Under the agreement, FWS issued the utility a 30-year incidental take permit for operations and maintenance activities in the nine Bay Area counties. The HCP includes strategies to avoid, minimize, and offset potential direct, indirect, and cumulative effects of PG&E’s O&M and minor new construction activities on 32 threatened or endangered species. The parties are hailing the landscape-scale plan as an improvement over the project-by-project process they previously operated under, as it will enable PG&E to complete projects more quickly...
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In Humboldt County’s coastal dunes, a multi-agency partnership is restoring the native plant community to build resilience to sea level rise.

The project, along with four others in the Bay Area and Southern California, is featured in a new report, Case Studies of Natural Shoreline Infrastructure in Coastal California. Much of the state’s dunescape was built over or hauled away before its value as habitat for unique species and a buffer against climate change was recognized. San Francisco’s dunes are long gone, and with them the endemic Xerces blue butterfly. Humboldt’s 32-mile stretch still shelters endangered plants like the Menzies’ wallflower...
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Smart Plover Predators

The South Bay’s salt pannes, bleak unvegetated flats left behind by commercial salt works, seem inhospitable to life. To western snowy plovers, though, they look like home. Still, the plovers are in trouble themselves. Considered a California species of special concern, the Bay-wide snowy plover breeding population sits at about 250. As Karine Tokatlian explained in her State of the Estuary Conference presentation in October 2017, efforts to boost their breeding success in the remaining salt pannes have encountered unexpected...
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Cold Curtain

Cold water, essential for the life cycle of Chinook salmon, is all too often in short supply along the Sacramento River. A primary cause: California’s massive water conveyance system, using reservoirs, dams, and hydroelectric plants to divert water and deliver power to farms and cities. “When we started releasing water in spring, we let cold water out too early. None was left by fall, when salmon really needed it,” says USBR hydraulic engineer Tracy Vermeyen. Two clever innovations have been...
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Small Natural Features, Big Ecological Benefits

One of the beauties of the Bay Area is that the landscape is rich in remnants of the wilderness that was once there. Journey through the ancient salt marshes and freshwater seeps of the tidal flats, to the grand old oaks casting shade over deep pools along seasonal streams, and even the precipitous cliffs of Alcratraz island. Every one of these has vast ecological benefits and comprise some of the Bay’s small but key natural features.
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