Just couple months ago, I had the opportunity to float the entire 280 miles of canalized white-water between the redrock walls of the Grand Canyon. I celebrated my birthday, solstice, Xmas, and New Year’s on the river along with with 13 rad folks.
As an ecologist (with a special interest in freshwater ecology), I felt incredibly fortunate to experience the new face of this watercourse which had been radically changed by a “High Flow Experiment” just a moth earlier. Also, I was out-of-my-mind excited to see some of the first wild-fledged California condors in Arizona while on the river. So, in addition to lots of photos from the trip, the end of this post contains a fair bit of nerd-splaining about river ecology and the condor recovery program.
This trip was especially important to me because it brought my career as an environmentalist full circle.
At the beginning of May 2007, I was in a 13-passenger van towing a trailer full of gear headed from northern Wisconsin to Arizona. At the helm was an English professor named Alan Brew. He was carting us out to the desert to spend a month reading the works of Edward Abbey while visiting all of the places where “Cactus” Ed had put those words to paper.
The discussions we had around the fire, during breathless hikes, and among sandy van seats helped form the bedrock of my wilderness ethics. And in no small way, that trip helped impel my career as a conservationist. To this day, when someone asks what I do for a living, my first impulse is to respond with a quote from one of Abbey’s books:
“My job is to save the fucking wilderness. I don’t know anything else worth saving.”
The most influential of Abbey’s books, for me, was his novel The Monkey Wrench Gang. It tells the story of a small posse of unlikely activists who refine the art of environmental sabotage (“monkey wrenching”) in escapades across the American West. The book culminates in the posse’s attempt to blow up the pinnacle of their ire–the Glen Canyon Dam, the dam that plugged the Colorado River just upstream of the Grand Canyon.
As it did for many generations before me, The Monkey Wrench Gang served as a distillation of all my frustration with the environmental catastrophe of modern society (the books was an inspiration for the first-wave of environmental activist organizations like Earth First! and later, for eco-terrorist groups like Earth Liberation Front). Above all else, the lesson I took from TMWG was that the Glen Canyon Dam represents the domestication of the willy Colorado River. It is a metaphor for everything wrong with our approach to natural systems. And I wanted nothing more than to see the fucker demolished.
Now, over a decade later, I got the chance to float the neutered stretch of the river between Glen Canyon Dam and the bolus of water backed up by the Hoover Dam downstream.
We put in just under Glen Canyon Dam on December 14 under a waxing moon and pulled out at Lee’s Ferry on Lake Mead 17 days later feeling (and smelling) like whole new people.
The High-flow Experiment:
So, why are dams so bad for river ecosystems?
River ecosystems, and especially desert riverine systems, are tough places for organisms to exist. Only specialized species can cut it here. River banks are constantly flooded and then parched. Entire sections of banks are washed away in high-flows and redeposited elsewhere downstream. During storms, the river turns turbulent and chocolate brown with suspended sediment, yet during the summer, the water can be still as glass, warm, and oxygen-starved.
Despite the hardships, or rather because of them, organisms have evolved to synchronize with the seasonal fluctuations of the river. Trees rely on bankful rivers to deposit seeds. Insects rely on high-flows to blast the silt out of the stony crevices they call home. Even frogs rely on the high pools left by receding waters as nurseries for tadpoles.
Dams stifle the natural flows of rivers and dampen natural flood events. Instead of seasonal peaks of silt-rich waters, dams reduce the river to a steady, nutrient-saturated but silt-poor trickle. In general, the entire system is engineered for the annual catastrophism of raging floods. Without that annual reset, a few species can come to dominate at the expense of overall biodiversity.
In order to restore down-stream ecosystems, researchers have begun to experiment with creating artificial floods by releasing high-volume surges from the bottom of dams. Releasing from the bottom of the dam purges the sediment build up behind the wall and flushes it downstream.
At Glen Canyon, the first High-Flow Experiment (HFE) was conducted in 1996. Follow-up trials were conducted in 2004 and 2008, and then annually since 2012. During an HFE, flows peak at between 38,000 and 45,000 cfs–about double the average base-flow.
While HFEs help simulate minor floods, they do not replicate natural flow patterns. Take a look at the flow plot from 1920-2010. Before Glen Canyon Dam, annual floods peaked over 100,000 cfs every five years or so, at times exceeding 150,000 cfs, which is double or triple the peaks of HFEs.
The HFE program is certainly better for the river than continual flows, but probably will not restore long-term ecological processes. For instance, during our trip, those folks who had been on the river in years past were surprised to see how some of the camping beaches had changed. Ecologically, that’s a good thing, because it establishes a natural successional regime. However, the changes were nominal and limited to the immediate banks while the upper beaches were unaffected. One reason for this is that a history of consistent flows allowed woody vegetation to develop deep roots that anchor the upper beaches in place. Historically, annual floods would have prevented most plants from this type of entrenched colonization, and the irregular massive floods would have removed those plants that had begun to establish themselves. The result is that a post-succession regime currently dominates most beaches, choking out important ephemeral habitats, and every year they grow more recalcitrant to floods.
California condors:
Up close, condors are ugly birds. They kind of look like Mitch McConnell wearing an Ewok suit. But when you see them gliding along the elevated skyline of the Grand Canyon’s rim, they seem both majestic and imposing. With a wingspan of 9.5 feet, they are the largest bird in North America.
The story of the condors is one of the greatest successes of the environmental movement. Due mainly to lead poisoning, the California condor population crashed to just 22 individuals in the entire world in 1982. Condors are carrion specialists and especially like the large carcasses left by hunters. Unfortunately, the lead shot in bullets remains in the carrion and ends up in the birds. Over the years, the populations dwindled as more and more birds died of lead toxicity before reproducing. Without intervention, the species would have been extinct by the end of the century.
Over the next 5 years, the Fish and Wildlife Service managed to capture all of the remaining birds and placed them in a captive breeding program. By 1992, the captive population had tripled and the first new birds were released back into the wild. Over the next couple of decade, the captive population grew and new captive breeding programs were established. At the same time, new individuals were released and new reintroduction sites were established, including the second release site in Arizona.
We saw condors on the first day of our trip, just a couple of miles downstream of the dam. Judging from the broken white bands under the wings, these were probably juveniles. That’s super exciting because it means that these were wild-fledged birds from released parents. As of 2017, there were over 60 wild-fledged condors and that number keeps rising.
The future of the condors looks hopeful. In 2011, for the first time since the recovery effort began, the number of condors in the wild exceeded the number in captivity–290 to 170 as of 2017.
But there remains cause for concern. Lead poisoning continues to impact the wild populations. In fact, USFWS expects that every wild bird will need to be treated for lead toxicity at some point in its lifetime and lead toxicity can be blamed for the majority of deaths. Finkelstein et al. (2012) used isotopic analysis to trace the origin of the lead found in birds—no surprise—the predominant source of lead was from ammunition.
Despite the fact that we’ve known for decades that lead causes major harm, no legislation has been passed to ban lead in bullets. We can continue to supplement wild populations with captive breeding programs, but until we manage to fix the problem of lead in the environment, condors will never be self-sustaining.
Fortunately, a lead ammunition ban is supposed to go into effect in California this year. However, populations in Arizona, Utah, and Mexico will continue to suffer from poor hunting practices.
Resources and references:
U.S. Fish and Wildlife – California Condor Recovery Program
National Park Service – Condor Re-introduction & Recovery Program
Glen Canyon Dam Adaptive Management Wiki
Finkelstein, M. E., Doak, D. F., George, D., Burnett, J., Brandt, J., Church, M., et al. (2012). Lead poisoning and the deceptive recovery of the critically endangered California condor. Proc. Natl. Acad. Sci. U. S. A. 109, 11449–11454.
Poff, N. L., and Schmidt, J. C. (2016). How dams can go with the flow. Science 353, 1099–1100.
West, C. J., Wolfe, J. D., Wiegardt, A., and Williams-Claussen, T. (2017). Feasibility of California Condor recovery in northern California, USA: Contaminants in surrogate Turkey Vultures and Common Ravens. doi:10.1650/CONDOR-17-48.1.