To monitor the native species, which include plump speckled dace and slippery bluehead suckers in addition to the chub, workers bait and set heavy, conical hoop nets and boxy minnow traps for a 24-hour period. After wading through ice-cold and often chest-deep water, the crews haul in the nets, excitedly searching for humpback chub as if they were old friends. "We consider them like children at times because we've seen the whole process and watched them grow," says fisheries technician Amy Martin. "This project is a proactive conservation measure that is helping to protect the genetic populations. It's hard work, but it feels good at the end of the day." Healy agrees: "Chub are part of what make this place unique, so we set the bar high for how we want the park's resources to be managed."
So far, the efforts appear to be paying off. In addition to the new evidence of reproduction in Havasu, the percentage of released chub that remain in Shinumo Creek has nearly doubled from the first to the third years.
Future fisheries management
This conservation work will continue under the park's new 20-year Comprehensive Fisheries Management Plan, which covers the Colorado River from Glen Canyon Dam to Lake Mead. The plan's goals include maintaining the recreational rainbow trout fishery just below the dam as well as continuing to restore native fish populations in the tributaries. As the only endangered fish known to reproduce in the park, the humpback chub will remain the primary focus, but the plan also includes a feasibility study for the reintroduction of the endangered Colorado pikeminnow as well as a research and augmentation plan for the endangered razorback sucker, one specimen of which was found in the park last year for the first time since the 1990s, according to Healy.
Whether this fish tale will have a happy ending, however, is still open to question. The recent government shutdown forced Healy to cancel a fall monitoring trip to Havasu as well as postpone a collection trip to the Little Colorado River and additional electrofishing trips to prepare Bright Angel Creek, the final tributary selected for chub translocations. The resulting data gaps will increase the margins of error in future population models, and the postponed trout removal could cancel out months of previous electrofishing work.
Healy is also concerned about the potential threat to native fish from predators other than trout as the discharge from Glen Canyon Dam warms due to dropping reservoir levels. "Warmer water might increase the numbers of warm water, nonnative fishes such as smallmouth bass, striped bass and channel catfish, which are voracious," Healy says.
Conserving the Grand Canyon's native fish ultimately comes down to choices. "We've made some enormous changes to this whole river system," Trammell says. "We can make the choice to try to undo some of the damage that we've done." Healy, who likens the Grand Canyon ecosystem to an airplane, agrees: "If you're going to be flying an airplane, how many bolts can you afford to lose from the plane before you start feeling nervous?"