Nighttime lights on bridges shining into bays and rivers can attract and confuse fish as they migrate at night, leaving them vulnerable to predation.

Native Species



13
Aug

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.” The Sundial Bridge in Redding is thought to have contributed to low numbers of fall-run Chinook salmon on the Sacramento River between 2011 and 2013. The Bay Institute’s Jonathan Rosenfield agrees that the problem from lights should be mitigated whenever...
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13
Aug

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 high census numbers are unprecedented since robust surveys began in 1975. The move appears to coincide with the onset of “the blob,” a marine heat wave that formed off the California coast starting in 2014. California sea lions prey on...
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13
Aug

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 similar results, with the fish being exposed to multiple human medications and other products. The mussels tested were not wild mussels but clean mussels the researchers had transplanted from an aquaculture farm on Whidbey Island to locations near the port...
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02
May

The country’s tiniest falcon—the stunning American kestrel—is declining throughout the United States, and California seems especially hard hit: Kestrel numbers during the Golden Gate Raptor Observatory’s annual autumn migration counts declined from nearly 800 in 1997 to just 300 in 2017.

“Kestrels in California have been on a long downward trend since 1950 at least,” says GGRO Director Allen Fish, citing several potential reasons for the decline, including predation by other raptors. Pesticides destroy important food sources for kestrels and also sometimes poison the birds themselves. Rodenticides and insecticides work their way up the food chain and cause secondary poisoning, as do heavy metals like selenium, mercury, and lead. Loss of nesting sites is another problem: kestrels are cavity nesters and rely on old woodpecker holes and tree hollows; they do not excavate their own cavities. Very old trees are becoming harder to find in managed forests, says Fish, and dying trees with potential nesting cavities are often treated as fire...
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02
May

Napa County voters will weigh in on the fate of the county’s remaining oak woodlands this June, when they cast ballots on Measure C, the Watershed and Oak Woodland Protection Initiative.

“Ninety-five percent of oaks on the valley floor are gone and we want to do a better job reducing deforestation on the hills” initiative co-author Jim Wilson, told the Bay Area Monitor. “Our hillsides are beautiful and also filter rain, keeping water clean as it replenishes aquifers.” Most of Napa’s oak woodland loss is due to vineyard development, and the county General Plan projects that another 3,000 acres of woodland will be converted to vineyard by 2030. Current protections require that two replacement oaks be planted or preserved for every mature tree felled, and oaks on slopes steeper than 35 percent and in riparian forests along streams are protected. Measure C would increase the replacement requirement to three trees for...
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18
Mar

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 implemented to conserve cold water into the autumn. First: A 300 foot tall, 250 foot wide “adjustable straw” possessing a series of intake gates enables power plant operators to draw water from behind the dam at three different depths. Second:...
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07
Feb

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 while protecting more land for mitigation and increasing opportunities for passive recreation such as hiking and bird watching. However, some environmental groups are concerned that the plan does not cover several species that should have been included. In addition, says...
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07
Feb

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 and beach layia. Invasive European beachgrass not only chokes out natives; it pins the dunes in place, constraining their ability to move inland as the sea encroaches.  Led by US Fish and Wildlife Service biologist Andrea Pickart, federal and state...
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13
Dec

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 challenges. Predator management resources for the Eden Landing plover colony are limited, according to Tokatlian. Fencing nests work better against mammals, but the plover’s primary predator is the common raven. Relocated predators find their way back. Research on these birds’...
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13
Dec

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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13
Dec

Searching for a Few Good Weevils

“They’re pretty charismatic,” says Julie Hopper of the tiny herbivorous weevil N. bruchi. Native to Argentina, these weevils were first brought to North America to combat the spread of the invasive weed water hyacinth.
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13
Dec

Coyote’s Cache of Intermittent Riches

There’s a common perception in California that more water is always better for fish. Yet many native species possess traits that allow them to persist through harsh, dry summers and cyclical drought. Over the long run, summer releases from reservoirs and urban runoff can harm local fish by laying out a welcome mat for non-native species adapted to perennial flows, Leidy says. “In areas where streams have been altered by humans, where the natural hydrograph has changed, that’s where you see invasives take a foothold.” Coyote Creek’s strictly seasonal flows, and those of other naturally intermittent streams in the state, by contrast, are so extreme in the winter and so sparse in the summer that non-natives simply can’t cope. “It’s...
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13
Nov

The number of Chinook salmon returning to Central Valley rivers is near record lows as a result of water management decisions made during the recent drought.

Returns of endangered winter-run Chinook salmon this year will be the second lowest this century—according to the Bay Institute’s Jonathan Rosenfield, the final 2017 estimate is likely to be less than 1,000 fish total, of which more than 80% were hatchery-spawned. Returning fish represent the survivors of the 2014 incubation period, when the US Bureau of Reclamation did not provide adequate cold water, and poor juvenile outmigration conditions during winter-spring 2015 resulting from reduced Delta inflow and outflow standards. Despite all this, salmon continue to return to Northern California’s rivers; fall is the best time to witness this migration as water levels are at their lowest and the salmon are easiest to see. The Bay Institute, together with The Nature Conservancy and...
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13
Nov

In hot water due to climate change, many ocean fish are moving to higher latitudes or deeper waters to find the conditions they need to survive.

These include lobster, black bass, and Atlantic cod, all of which have supported iconic fisheries along the Eastern seaboard of the United States. “Ocean animals are moving ten times faster than animals fleeing climate change on land,” says Rutgers University marine biologist Malin Pinsky, whose Rutgers OceanAdapt website enables visitors to explore changes in marine species distributions over recent decades. These range shifts are causing headaches for fishing fleets, which are forced to head farther out to sea or hundreds of miles further from home ports. But fishes moving north face a catch-22: Water absorbs carbon dioxide more readily when cold, meaning rising greenhouse gas concentrations are causing the oceans to acidify much faster at the poles. KMW
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05
Oct

Sturgeon Surgeons

“White sturgeon are a popular species, so we want to keep a close eye on contaminants in their tissues.” Recent RMP studies have unearthed a few new interesting things about sturgeon - first that selenium keeps turning up in specimens from certain areas, and second that testing may not have to be deadly. Growing up to 20 feet long and living up to 100 years, today’s living fish have become valuable for the stories that they tell.
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05
Oct

Toxic Summer for Sea Lions

The Marine Mammal Center in Sausalito is wrapping up a busy summer. A potent neurotoxin called domoic acid, propagated by toxic algal blooms, poses a threat to California sea lions. Originally called “Amnesiac shellfish poisoning,” domoic acid targets the hippocampus and can have devastating effects on sea lions.
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15
Aug

Sport Fish Still Not Squeaky Clean

Toxic flame retardants quickly declined in Bay-caught fish, once banned, but legacy mercury persists, according to the most recent year of sampling. As the region’s collaborative monitoring program for Bay contaminants — the RMP — arrives at its 25th birthday, its long-term commitment to consistent data collection for the purposes of targeted environmental management is showing its mettle. The RMP has been catching and testing a wide array of species of popular sport fish, ranging from giant sturgeon to tiny sardines, since 1997. This June the program debuts the latest results. There’s good news, bad news, and no news. PBDEs, those sticky flame retardants linked to cancer, and sprayed on fabrics and couches, have continued their steady decline over the...
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11
Aug

Man’s best friend is being enlisted in efforts to detect the soil-born pathogen responsible for sudden oak death and other rapidly spreading plant and tree diseases.

Phytophthora is difficult to detect in nurseries, plant materials, and planting sites until it has done its damage. To develop early-detection options, H.T. Harvey and Associates are training a female cattle dog/border collie mix named Bolt to sniff out Phytophthora. Part of the Harvey Dog ecological-scent detection program, Bolt has accurately identified four species of Phytophthora in the lab. If her training in a natural setting is successful, Bolt could get to work helping minimize the spread of Phytophthora. Potential beneficiaries would likely include those working to re-oak the parks, open spaces, and backyards of Silicon Valley to improve habitat for native plants and animals.  KMW
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09
Aug

Advocates for Alameda Creek are concerned that a new proposal to beef up passenger rail service between Stockton and San Jose would jeopardize water quality and wildlife habitat.

Niles-based Alameda Creek Alliance says the proposed expansion of the Altamont Corridor Express (ACE) passenger rail service might also bring increased freight train traffic to narrow, steep Niles Canyon, creating a situation that could lead to possible derailments and creek-contaminating spills. (A passenger train derailed into the creek in 2016.) Niles Canyon is the critical mid-point of complex watershed-wide work to reduce erosion, improve flood control, and restore steelhead to the creek. The Alliance and others are asking for a more thorough environmental impact assessment and more clarification about what kinds of uses of the railway will be permitted in the future. DM
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08
Aug

Small-scale conservation can have outsized ecological impacts, says an international group of researchers.

Among the small natural features that can have disproportionate ecological value are the bark of grand old trees, which has nooks and crannies that provide microhabitats for wildlife; patches of native plants alongside agricultural fields, which can provide some species with their only remaining natural habitat; and rocky outcrops, which nurture unique and diverse flora and fauna. Other benefits of conserving these modest yet influential—and often under-appreciated—landscape features include relative ease and affordability as well as compatibility with land uses such as grazing and forestry. Even seemingly minor features, the researchers say, can have “roles that may be critical in the function of their broader ecosystems and the fate of biodiversity.” RM
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