Larry Stevens
scientist, author, publisher, commercial guide, musician, private boater

Science and the Future of Grand Canyon

   The charge we each and collectively share at Grand Canyon is seeing without harming, delivering it to future generations in all its magnificence and intimacy, with its full compliment of species and ecological processes. We can only trust that future generations will come to revere it, as we do, as sacred ground, and that they will recognize by seeing it the need to leave it sound and whole, as a refuge of the human spirit for yet the next generation to witness. Our task, as enlightened beings, is to honor this Canyon, and learn enough about it to guarantee its future well-being.

   We sentients change things by looking at them, and our impact on this remarkable landscape during our own generation has been profound. Major changes have taken place, and are taking place. Flow regulation has had the odd impact of increasing biodiversity and productivity in the river corridor, changes which have occurred somewhat at the expense of that in the aquatic domain. Many non-native species have colonized the low elevations, and some, such as tamarisk, camelthorn and the brome grasses, have become dominant.

   Although many species’ populations have increased in the river corridor, at least nine vertebrate species have disappeared, or are perilously close to extirpation, in the past 30 years. These species include razorback sucker, bonytail and roundtail chub, Colorado squawfish, northern leopard frog, zebra-tailed lizard, Colorado River otter, muskrat, and southwestern willow flycatcher. These species losses are all recent, and stand apart from the extirpation earlier this century, of sage grouse, California condor (recently reintroduced), Great Basin timber wolf, and jaguar. The loss of large predatory vertebrate species at Grand Canyon is particularly troubling because top predators tie together the many loose ends of food webs and other ecological processes. Once gone, large predator populations are difficult or impossible to restore, so they also serve as important monitoring indicators of how we have done at protecting Grand Canyon in perpetuity.

   Protection and enhancement of the values for which Grand Canyon National Park was established involves the reinvention of scientifically credible and accountable management. Such management would include rigorous inventory and monitoring of the Canyon's flora and fauna. Although modest data exist for some Grand Canyon bird and fish species, little to no information is available on the status of desert bighorn sheep, desert mule deer, mountain lion, or virtually any other native terrestrial vertebrates in Grand Canyon, not to mention invertebrates. This information can contribute to proactive management strategies to protect and enhance those populations and ecological processes for which this landscape is so famous. Active reintroduction of extirpated species should be a high priority.

   The NPS claims their top priority for the river corridor is to manage it for its natural condition, but such a goal is utterly impossible if the status of those populations remains unknown. External review of management activities by qualified, unbiased scientists is a necessity, because it provides the credibility needed to support tough, controversial decisions. Disclosure to the scientific community and to the public is also required to further the credibility of management. Better science is needed at the forefront of policy, not as an aftersight when the springs have all gone dry. This may reduce the endless back-peddling into trade-offs that sell out the Canyon's resources, one by one.

   The focus on "enhancement of the visitor experience" is untoward, bound up as it is in the elliptical reasoning of a "preserve-for-enjoyment" mandate. In fact, it rather sounds like "maximize the diversity of dining experiences," which has become the developer's credo outside the Park's South Rim.

   None of us should forget that we are trying to maintain the integrity of Grand Canyon's fleet of ecosystems, sailing together through time. Preservation and protection of the wild landscape will help teach those future generations about existence values, about beauty and about real freedom. A much stronger role for science is warranted at this Park, and it will help prevent further incremental loss of our natural heritage.