Bison are back, and that benefits many other species on the Great Plains — The Conversation

From The Conversation (Matthew D. Moran):

Near extinction

It was not always certain that bison could rebound. Once numbering in the tens of millions, they dominated the Great Plains landscape until the late 1800s, anchoring a remarkable ecosystem that contained perhaps the greatest concentration of mammals on Earth. That abundance was wiped out as settlers and the U.S. government engaged in a brutally effective campaign to eradicate the ecosystem and the native cultures that relied on it.

Bison were shot by the millions, sometimes for “sport,” sometimes for profit, and ultimately to deprive Native Americans of vital resources. By 1890 fewer than 1,000 bison were left, and the outlook for them was bleak. Two small wild populations remained, in Yellowstone National Park and northern Alberta, Canada; and a few individuals survived in zoos and on private ranches.


Remarkably, a movement developed to save the bison and ultimately became a conservation success story. Some former bison hunters, including prominent figures like William “Buffalo Bill” Cody and future President Theodore Roosevelt, gathered the few surviving animals, promoted captive breeding and eventually reintroduced them to the natural landscape.

With the establishment of additional populations on public and private lands across the Great Plains, the species was saved from immediate extinction. By 1920 it numbered about 12,000.

Bison remained out of sight and out of mind for most Americans over the next half-century, but in the 1960s diverse groups began to consider the species’ place on the landscape. Native Americans wanted bison back on their ancestral lands. Conservationists wanted to restore parts of the Plains ecosystems. And ranchers started to view bison as an alternative to cattle production.

More ranches began raising bison, and Native American tribes started their own herds. Federal, state, tribal and private organizations established new conservation areas focusing in part on bison restoration, a process that continues today in locations such as the Tallgrass Prairie National Preserve in Kansas and the Fort Peck Reservation in Montana.

By the early 2000s, the total North American population had expanded to 500,000, with about 90 percent being raised as livestock – but often in relatively natural conditions – and the rest in public parks and preserves. For scientists, this process has been an opportunity to learn how bison interact with their habitat.

Improving prairie landscapes

Bison feed almost exclusively on grasses, which, because they grow rapidly, tend to out-compete other plants. Bison’s selective grazing behavior produces higher biodiversity because it helps plants that normally are dominated by grasses to coexist.

Because they tend to graze intensively on recently burned zones and leave other areas relatively untouched, bison create a diverse mosaic of habitats. They also like to move, spreading their impacts over large areas. The variety they produce is key to the survival of imperiled species such as the greater prairie chicken (Tympanuchus cupido) that prefer to use different patches for different behaviors, such as mating and nesting.

Bison impacts don’t stop there. They often kill woody vegetation by rubbing their bodies and horns on it. And by digesting vegetation and excreting their waste across large areas, they spread nutrients over the landscape. This can produce higher-quality vegetation that benefits other animals.

Denver: Heron Pond redevelopment poses environmental challenges

Proposed Heron Pond Park via the City of Denver.

Click here to read the master plan.

From The Denver Post (Bruce Finley):

The 2-foot-deep pond holds toxic sludge laced with lead, arsenic and cadmium. Contaminated stormwater runoff from surrounding work yards worsens the brew…

Denver’s willingness to embrace such a site for future parkland reflects the increasingly difficult challenge of establishing enough public green space to keep pace with population growth and development. Denver has fallen behind other U.S. cities in urban parks and open space. This is causing discomfort, hurting public health, exacerbating heat waves and risking costly problems with stormwater runoff.

City officials interviewed by The Denver Post said they see establishing new green space as essential but, perhaps, impossible given the rising price of land. Yet voters recently ordered a sales-tax hike that will raise $45 million a year for parks and open space. This has compelled planners to pore over thousands of acres that could be preserved as green space.

The problem, city officials said, is competing with private developers for land. Developers since 1998 have installed buildings, paved over natural terrain and otherwise overhauled vast tracts of the city — profiting from shopping plazas and upmarket apartments that eventually sell as condominiums. They’ve built higher, lot-line-to-lot-line in some areas, leaving less space to even plant trees.

Turning to marginal industrial land, city officials said, may be Denver’s best hope for stabilizing a decline in green space per capita.

Chief parks planner Mark Tabor said that, after establishing the new green space around Heron Pond, Denver officials could try to purchase the land around the Arapaho power plant south of downtown and in the rail yards northwest of downtown for preservation as large green space where natural ecosystems could be restored.

This approach hinges on cleanup.

It can be done, not just by excavating and hauling away contaminated soil but by using modern cleanup methods that remove acidity and toxic metals, said Fonda Apostopoulos, a Colorado Department of Public Health and Environment engineer who managed decontamination of the Asarco smelters and 862 residential properties near Heron Pond.

“The low-lying fruit of clean property in Denver is few and far between. ‘Brownfields’ are pretty much the only property people are developing,” Apostopoulos said.

“It is all about exposure pathways” — the ways contamination can reach people, he said.

Around Heron Pond, cleanup included excavation and replacement of soil around homes. Nine new monitoring wells will be installed between the smelter site and the South Platte River to make sure toxic metals no longer contaminate groundwater, Apostopoulos said, pronouncing the area safe for at least passive recreational activity.

While cleaning up industrial wasteland costs hundreds of millions of dollars, “there are a lot of private-public partnerships that could do that,” he said. “Denver could get extra federal funding. They could get cleanup grants.”

Proposed Heron Pond boundary via the City of Denver.

Cache la Poudre: Fish ladder coming to the Poudre River at Watson Lake — #Colorado Parks and Wildlife

Construction begins on Cache la Poudre River for fish ladder near Watson Lake. Photo credit: Jason Clay/Colorado Parks and Wildlife

Here’s the release from Colorado Parks and Wildlife:

CPW partners with noosa yoghurt, Northern Water and Morning Fresh Dairy on project

[In December 2018] a project [broke ground] that will help reconnect a fragmented Poudre River.

In a collaborative effort, Morning Fresh Dairy, Northern Water and noosa yoghurt are partnering with Colorado Parks and Wildlife (CPW) to put in a fish ladder at the Watson Lake Diversion. They hope this will be one of many ladders along the Poudre River that will allow fish to travel freely, improving the health of the fishery and the ecosystem.

This Watson Lake fish ladder will reconnect over two river miles. The stretch contains important spawning habitat and deep pools that provide refuge for aquatic life.

Watson Lake Diversion Structure is a channel spanning structure that represents a complete barrier to all upstream fish movement in the Poudre River. The structure delivers water to Watson State Fish Hatchery and is owned and operated by CPW.

“We appreciate the collaboration from the project partners on this important fishway that will reconnect over two miles of stream habitat for the aquatic species,” said Kyle Battige, aquatic biologist for CPW. “Supporting fish passage at Watson Lake aligns with CPW’s goal through improving several facets: ecosystem health, angler access, public safety and public education.”

Designed by OneFish Engineering, the fish ladder will provide upstream fish movement through the diversion structure for all species present within the river reach including longnose dace, longnose suckers, white suckers, brown trout and rainbow trout. The State Wildlife Area and Hatchery, where this project is located, receives a lot of visitors whether they are fishermen, birders, or families enjoying nature. Onsite educational material discussing fish passage will be an important component of the project providing a learning experience for school children and all other visitors.

“The Poudre River has been an integral part of our family farm for over 100 years. We would like to be part of the solution for fish passage along the Poudre River, starting at Watson Lake,” says Rob Graves, owner of Morning Fresh Dairy and co-founder of noosa yoghurt. “We would like to find additional community partners and reconnect the river from Fort Collins all the way up through the Poudre Canyon.”

The new fish ladder also fulfills one of the promises made by the participants of the Northern Integrated Supply Project to improve the Poudre River, outlined in the NISP Fish and Wildlife Mitigation and Enhancement Plan.

“This project shows the commitment of project participants to address the overall health of the Poudre River,” said spokesman Jeff Stahla. He noted that participants have committed to spending $50 million on a state of Colorado Fish and Wildlife Mitigation and Enhancement Plan that includes minimum daily flows on the Poudre River through downtown Fort Collins, the construction of fish bypasses and other measures throughout the area

The project started in December 2018 and will be completed in March 2019 before spring runoff begins on the Poudre River. One of the goals is to help move other fish passage projects forward on the Poudre River. Local ditch companies will be able to observe one of these projects first-hand and see that there is no negative impact to water delivery. This will be an important resource to move fish passage initiatives forward with other diversion structures.


Morning Fresh Dairy
Stephanie Giard

Northern Water
Brian Werner

Colorado Parks & Wildlife
Jason Clay

noosa yoghuer
Stephanie Giard

Northern Integrated Supply Project (NISP) map July 27, 2016 via Northern Water.

#SaltonSea restoration update

From National Geographic

The struggle to preserve the Salton Sea rages on as its shoreline retreats.

During migration season, birds pack the wetlands at the edge of the Salton Sea. Ducks dive, pelicans skim across the water’s surface, and hundreds of other species stalk the shores and bob on the surface of California’s largest, and most unusual, lake.

The Salton Sea is a vast, shallow body of water percolating in the hot desert inland of San Diego and a key stopover point for many birds migrating along the Pacific Flyway. Over the years, as other wetlands along the flyway have been lost to development, drought, or other causes, it has taken on an outsized importance for migrating birds. Nearly all of California’s population of eared grebes, for example, stop over at the lake, and at least a third of all the white pelicans living in North America dip in and out of its waters on their migratory travels.

(See the intricate migration pathways birds take around the world.)

Caption: Imperial Valley, Salton Sea, CA / ModelRelease: N/A / PropertyRelease: N/A (Newscom TagID: ndxphotos113984) [Photo via Newscom]

But the Salton Sea is shrinking. Because of a host of reasons climate-related, agricultural, and political, less and less water ends up trickling into the lake each year, while the hot desert sun keeps evaporating its water away. And a year ago marked the end of some state-mandated inputs of extra water that had been keeping the Salton Sea relatively full for about 15 years. Without that extra water, the lake’s shrinking will start to accelerate—making it saltier, smaller, less welcoming to the birds that rely on it during migration, and more harmful to the people who live near its shores…

Southern Pacific passenger train crosses to Salton Sea, August 1906. Photo via USBR.

The Salton Sea took on its modern mien about 100 years ago, when an irrigation canal full of water from the nearby Colorado River broke open. It took nearly two years for the breach to be fixed, and in the meantime, Colorado River water gushed down into the Imperial Valley. The valley, as it happened, had no outlet, so the water pooled in a depression near its northern end, in the hollows left behind from lakes that had filled and dried that region many times over the geologic past. Eventually, the waters ballooned out, forming a vast, glistening inland lake covering over 350 square miles. And thus was born the modern Salton Sea.

But the lake was in a hot, dry part of the world where summer temperatures routinely hover far above 100F. Left to its own devices, it would have quickly evaporated away in the beating desert sun. But in the 1920s, locals decided to use the lake as a place to divert all the water that ran off the farms that carpet the surrounding valley. In essence, they put the lake on long-term life support. The district had rights to vast quantities of Colorado River water, and agriculture was booming in the valley, so in those early decades plenty of runoff went rolling downhill into the lake.

Wild birds quickly flocked to this new oasis in the middle of a desert. In 1930, a wildlife refuge was established in its fringing wetlands, and it quickly filled with birds and bird watchers. Over the years, over 400 species of birds have been spotted along the shores of the lake—nearly half of all species observed in the entire U.S…

The new reality—and the debate about solutions

The full extent of the new reality for the Salton Sea hasn’t yet fully manifested, says Bruce Wilcox, a secretary with the California Natural Resources Agency who oversees Salton Sea policy. The lake’s surface has dropped about twice as much this year as it did the year before, but it will take some time to really feel the impacts, he says.

But the future is going to be challenging under the best of circumstances, Wilcox warns. Over the next decade, the lake is projected to shrink by thousands of acres each year, exposing nearly 100 square miles by 2028, and nearly triple its current salinity—unlivable for most things that live in water and inhospitable to anything else along its shores.

The loss of the water was not a surprise: some variant on this plan has been in the works for decades. Shoreside debates have raged over how to manage the shrinking lake. Some want to fill it back to its mid-century depths, in an attempt to recapture its glitz and glamour. Others want to do whatever it takes to keep the wetlands habitat intact.

Currently, the state has a plan in place to reconstruct wetlands over about half of the area that will be exposed in the next decade. But so far, the plans have been stalled, with only one project on the southern end of the lake inching forward.

But all it will take is action, says Cohen. “It’s a pretty straightforward concept,” he says. “Once you put up the water and build the wetlands, the birds respond quickly; there’s a huge explosion of biological activity.”

And at the same time, the costs to human health from a shrinking lake have grown more obvious. As the lake recedes, it leaves behind vast swaths of playa, full of fine-grained material that had collected on the lake bottom over the last century. Wind kicks up dust from the playa, which irritates lungs and is loaded with all the compounds and materials that have run off from agricultural lands over the years. Exactly what’s in the playa dust and what that does to human lungs is not yet fully known, but it could include a slew of organic compounds and minerals that exacerbate the already high asthma rates in the county.

“We think there is something else besides the mineral composition that’s causing health impacts,” says Roya Bahreini, an atmospheric scientist at the University of California, Riverside, who has been studying the dust from the region. “But we don’t know what it is yet.”

All plans to deal with the shrinking lake focus heavily on tamping down the playa dust. “Now, this is a desert, so we will never stop dust from blowing,” says Wilcox. But many different strategies—from dumping water on the surface to building landforms that interrupt the winds’ path over the dusty playas—are being tested and, hopefully, implemented soon, says Wilcox.

The whole project is a mess of urgent needs, says Wilcox. “It’s like a big envelope of Jello,” he says. “If you push in one area it pokes out in another area.”

But something has to be done, says Lucia Levers, a water researcher at the University of Minnesota whose research has focused on the Salton Sea. The replacement wetlands being built to make sure the migrating birds still have their stopover spot are better than nothing, she says—at least they’re some kind of substitute for the key habitats that are being lost as the lake shrinks and gets saltier. But the bird populations are already fragile, since they’ve lost so much of their other habitat along the flyway. So if the replacement wetland habitat doesn’t get built, and soon, well—”there’s no substitute for the substitute. This is the end of the line,” she says. “And if this spot goes, it’s all going to go.”

Some funding available in #FarmBill for the #SaltonSea #ColoradoRiver #COriver #aridification

Screen shot of drone video June 11, 2016. Credit Palm Springs Desert Sun.

From The Palm Springs Desert Sun (Janet Wilson):

The changes were negotiated earlier this year by Rep. Raul Ruiz, D-Palm Desert, and California Sens. Dianne Feinstein and Kamala Harris, both Democrats. The bill’s inclusion of the Salton Sea could also nudge California closer to approving a Colorado River drought contingency plan.

Officials said for the first time the Salton Sea now has access to guaranteed federal funding to help clean up environmental and public health issues caused by farming and water withdrawals. The sea, the state’s largest lake, is rapidly drying and releasing toxic dust clouds…

State officials have allocated a minimum of $10 million for a first phase program to build ponds and wetlands to cover growing stretches of dusty lake bed. The federal programs could provide matching funds or more.

The bill could also indirectly help with seven-state drought contingency plans to conserve Colorado River water.

The Imperial Irrigation District, which is entitled to the largest share of the river water, has signaled their support for one plan, but set conditions for signing it, including an ironclad guarantee of funding for the shrinking Salton Sea…

During talks in Las Vegas last week on the drought plans, Bureau of Reclamation chief Brenda Burman said, “I would caution folks … not to add unrealistic demands.”

IID president Jim Hanks fired back at her comments at a board meeting on Monday.

“It’s one thing to make bold statements from a Washington D.C. office or the luxurious Caesar’s Palace hotel ballroom. It’s something entirely different to see the shrinking sea or widening shoreline with your own eyes, or to witness a child or grandchild struggling to breathe due to their worsening asthma,” he said. “A shrinking sea … will blow untold quantities of fine dust in the air. … Matching federal funding for the Salton Sea makes up one-tenth of one percent of the $900 billion 2018 Farm Bill. That seems entirely reasonable.”

Photo credit San Luis Valley Heritage.

Meanwhile, down in the San Luis Valley the farm bill is welcome. Here’s a report from the Valley Courier via the Center Post Dispatch:

On Wednesday, Dec. 12, the House of Representatives passed the 2018 Farm Bill 369-47. The Senate passed the bill on Tuesday 87-13.

The Farm Bill, which among other provisions removes hemp from the list of federally controlled substances, now moves to the president’s desk for signature. The San Luis Valley is one of the areas in Colorado embracing hemp as a viable crop, and Colorado was the number-one hemp producing state in the nation last year with more than 10,000 acres.

Corbett Hefner, vice president of Research and Development for Power Zone Agriculture, a Valley company that has designed farm equipment to accommodate hemp production, said, “As an innovator developing hemp fiber-specific manufacturing technology, Power Zone is thrilled to see clarification at the federal level on industrial hemp in this Farm Bill. Thanks to this key step, we can take our business to the next level in rural Colorado and across the nation.”

Colorado State Senator and hemp producer Don Coram said, “As the sponsor of establishing hemp regulations in 2013 and actually becoming a hemp grower in 2017, I am thrilled that Colorado is leading the nation in this burgeoning new industry. The lack of clarity for hemp in federal law has long stalled the hemp industry from taking off. I appreciate Senator Bennet’s work on behalf of Colorado hemp growers to fully legalize the cultivation of industrial hemp. Colorado’s hemp industry will certainly benefit from this provision.”

Other agricultural leaders were also pleased with the passage of the Farm Bill.

For example, San Luis Valley resident and Colorado Farm Bureau President Don Shawcroft said, “The passage of the 2018 farm bill is welcome news for Colorado farmers and ranchers. Not only will it ensure the safety net for producers, maintain and expand environmental stewardship programs, promote international trade and provide needed support to disadvantaged families, it removes future uncertainty for an industry struggling amongst low commodity prices.”


Colorado Potato Administrative Committee Executive Director Jim Ehrlich said, “The new Farm Bill continues to make great investments for specialty crop producers in the research arena, including fully funding the Specialty Crop Research Initiative at $80 million annually, and reauthorizing the Specialty Crop Block Grant program. The potato industry has truly benefited from these programs. In addition, the bill provides important trade promotion funding through the Market Access Program and Technical Assistance for Specialty Crops program. Twenty percent of the U. S. potato crop is exported annually so a healthy trade environment is vital to the industry.”

Ehrlich added, “There are other provisions in the bill that will have potential positive impacts on the Valley as a whole, including making hemp legal nationally and eligible for crop insurance, and enhancements to the conservation title. In my opinion it represents a job well done by congress and how congress should function.”

Zoila Gomez, lead coordinator at San Luis Valley Local Foods Coalition’s Cooking Matters, said, “The reauthorization of the Farm Bill only strengthens our commitment in The San Luis Valley and across the state to continue to educate and motivate our participants to make healthy and physical activity choices within a limited budget through the Cooking Matters Campaign by Share Our Strength. We are grateful for all of those who advocated and voted for the Farm Bill … In an era of social media, people do love learning about nutrition, cooking healthy meals and dining together. The passing of the Farm Bill allows us to continue to bring together more people and move on with our mission.”

“On behalf of beef cattle producers in Colorado, we support the hard work toward passage and the outcomes of the 2019 Farm Bill, Colorado Cattlemen’s Association President Mike Hogue said. “The bi-partisan legislation will continue the meaningful work of ranches and farms in conserving our natural resources while opening up the world to our high-quality foods, like beef. Furthermore, CCA is pleased with funding that will go toward protecting our livestock from foreign animal diseases through additional research and preparedness. These points and others contained in the 2018 Farm Bill support the global approach to food security and stewardship our producers have.”

U.S. Secretary of Agriculture Sonny Perdue said, “The passage of the 2019 Farm Bill is good news because it provides a strong safety net for farmers and ranchers, who need the dependability and certainty this legislation affords. This Farm Bill will help producers make decisions about the future, while also investing in important agricultural research and supporting trade programs to bolster exports. While I feel there were missed opportunities in forest management and in improving work requirements for certain SNAP recipients, this bill does include several helpful provisions and we will continue to build upon these through our authorities. I commend Congress for bringing the Farm Bill across the finish line and am encouraging President Trump to sign it.”

Colorado Commissioner of Agriculture Don Brown said, “The passage of the 2018 Farm Bill is more than a success for U.S. farm and ranch families; it’s a powerful win for all Americans. This country relies on a strong, abundant supply of the food, fiber, and fuel provided by America’s agricultural community. The programs within the 2018 Farm Bill provide true value to the people of Colorado, including expanding the Conservation Reserve Program acreage and legalizing hemp to help create more consistent programs as a U.S. crop. In particular, adjusting the Agriculture Risk Coverage/Price Loss Coverage program provides a vital safety net for producers.”

Colorado Parks and Wildlife Director Bob Broscheid said, “Colorado’s wildlife and agriculture will both benefit from the 2018 Farm Bill; it’s a win-win. A long list of Colorado’s wildlife and recreation depends on working agricultural landscapes for food and cover, and the farm bill has several provisions that provide substantial incentives for farmers and ranchers to invest in practices that maintain wildlife habitat, as well as voluntary public access programs. Private lands are critical to Colorado’s quality of life, and this farm bill will provide the funding needed to ensure continued conservation of our soil, water, and wildlife.”

On Hope, Birds, and Tacos — @Audubon #ColoradoRiver #COriver

Great Blue Heron. By Terry Foote (talk) – Own work by the original uploader, CC BY 2.0,

From Audubon (Karyn Stockdale). Be sure to follow the links to learn about the birds:

Touring the last great wetland of the Colorado River Delta.

Recently, our Audubon Western Water team traveled across the Mexican border to visit the Colorado River Delta and what remains of Aldo Leopold’s green lagoons at the Ciénega de Santa Clara – a birder’s paradise less than 50 miles from the U.S. border. Some 75 percent of the endangered Yuma Ridgway’s Rail (among other species) rely on the Cienega de Santa Clara for food, nesting, and their life cycle.

We crossed at San Luis, Ariz. and were pleased to find that the bombast and hype around this border didn’t seem to phase folks living there. As with many international borders, there’s a sister town on each side that links families, friends and economies.

We toured with our local partners from Pronatura Noroeste, and learned about successful restoration efforts on the Rio Colorado. In just a few short years, native cottonwoods and willows planted and watered by local workers have taken hold in the restored river channels and wetlands. They created mini nurseries in this arid land to grow native plants and bring back wildlife. Walking through the rows and rows of irrigated trees, the Yellow-rumped Warblers, Blue-gray Gnatcatcher, and Gila Woodpecker were a delight.

We toured another Colorado River site, called Chausse, where partners Restauremos el Colorado worked similar restoration magic—a birder’s Big Day was taking shape when we saw the Osprey, Belted Kingfisher, American Kestrel, Northern Harrier Hawk, Spotted Sandpiper, and Red-winged Blackbird. Under the shade of some old remnant cottonwoods on the banks of the river, our partners wowed us with a cookout feast of grilled carne asada tacos, roasted chilis and onions, and guacamole. Heaven.

I didn’t think our trip could get any better, but then we found ourselves at the Ciénega de Santa Clara at sunset. This 40,000 acre wetland sits in the Colorado River’s abandoned deltaic floodplain, close to the Sea of Cortez—and it’s full of bird life. From the little dock, the turquoise boat, and up on the nearby watch tower, we spotted White-faced Ibis, American Avocets, American Coots, Common Gallinules, American White Pelicans, Great Blue Herons, and more. With our Mexican birding friends, we had a good laugh at the American naming emphasis for so many of these birds. Perhaps the most memorable bird was the Least Bittern—they called for hours eluding our binoculars and then flushed through the cattails right in front of us as we turned to leave.

The Ciénega de Santa Clara is alive and needs our help to protect it for future generations. There’s more work to be done in the Colorado River Delta, but we are witnessing the positive change envisioned years ago that is bringing back the river and birds that depend on these riparian and wetland habitats. Maybe next trip you’ll join us birding, eat some tacos, and find inspiration too. I returned back to my desk with my head and heart full of hope for our future.

Policies that save bird species will also save the planet.

Martha Gomez-Sapiens, a monitoring team member and postdoctoral research associate in the UA Department of Geosciences, stands on a riverbank next to willows and cottonwoods that germinated as a result of the pulse flow. (Photo: Karl W. Flessa/UA Department of Geosciences)

Razorback suckers are hanging on in the San Juan River

From The Denver Post (Bruce Finley):

U.S. Fish and Wildlife Service biologists counted 50 yearling razorbacks during a recent survey in the upper Colorado River Basin — the result of water releases in 2016 and 2017 from the Navajo Reservoir aimed at helping the fish, agency officials said this week.

Federal operators of the reservoir let out 5,000 cubic feet of water per second for 50 days, more than doubling regular flows in the San Juan River. This increased flow created nursery pools, the habitat razorbacks and three other endangered native fish need to spawn and survive.

Saving razorbacks and other fish “is going to be totally dependent ” on putting more water into rivers, said Tom Chart, director of the Upper Colorado River Endangered Fish Recovery Program, a 25-year, $360 million government-run rescue effort.

“We’re not going to be able to restore the natural hydrological conditions. We understand that,” Chart said. “But we can recreate conditions that help young fish much more regularly.”

Yet the intensifying climate shift toward heat and aridity in Southwestern states, combined with population growth, constrains biologists’ push to put more water into rivers for environmental purposes. No water could be released this year from the Navajo Reservoir, which straddles Colorado and New Mexico and holds 1.7 million acre-feet, Bureau of Reclamation engineer Susan Behery said. Probably none will be spared next year, either, because water managers are prioritizing storage after a near-record low snow year left the reservoir half full.

Raising, stocking razorbacks

For more than 30 years, federal biologists responsible for emergency rescues of endangered species have relied on raising razorbacks in hatcheries and copiously stocking them into Colorado River tributaries. Razorbacks evolved in wild free-flowing rivers, enduring for millions of years, until widespread dams and diversions reduced and regularized nature’s fluctuating flows. The razorback had nearly blinked out by 1980 with only 100 survivors — weakened by the disruption of flows and attacked by non-native predators such as bass, walleye and pike that state wildlife agencies have introduced for recreational sport fishing…

Federal survey crews counted the 50 yearling razorbacks along the San Juan River downriver from the Navajo Reservoir. That’s the most fish counted since the surveys began two decades ago. Fish and Wildlife Service biologists calculated that this many yearlings could mean there are thousands of razorbacks along a 180-mile stretch of the river before it reaches Lake Powell.

Navajo tribal biologists have embraced the effort to save razorbacks and other imperiled native fish. A Navajo team this year helped move 300 razorbacks over a barrier for spawning while weeding out non-native predators.

“We are trying to preserve the razorback for our future generations,” said Navajo fish biologist Jerrod Bowman. “So that our kids can see razorbacks. … Our numbers are really looking great.”

“Far from the self-sustaining populations”

The problem with officially upgrading the status of fish, Bowman said, is that just the presence of yearlings may not establish that a species has become self-sustaining as required. Razorbacks usually don’t reproduce until they’re at least 2 years old. Adults can live up to 40 years.

Under President Donald Trump, federal wildlife officials have faced pressure to upgrade and de-list endangered species when scientists still aren’t certain about survival, said ecologist Taylor McKinnon, a public lands campaigner for the Center for Biological Diversity.