A rare Southwestern trout stared extinction in the face. Now, you can fish for them. Conservation genetics and the dedication of professionals ensures this Mogollon Rim native fish has a future.
Craig Springer tells how a trout that once stared at extinction offers wilderness angling opportunities.
The trout stole its color from a southern New Mexico summer sunset.
Gila trout sport a painter’s pallet of pink and olive, rose, yellow and copper and a few tones in between. Beneath the black pepper flakes that fleck its side lies a lexis—a language carried forward from another time. It’s an ancient language coded in molecules of proteins written by the press of time and experience in a land turned arid.
Gila trout, native only to headwater streams that vein over the Mogollon Rim of New Mexico and Arizona, have expressed in their genetic makeup a mapping of how to survive in the vestiges of what surely was a large and contiguous range. Their genetics equip them to face what nature may hurl at them in an already harsh environment.
It’s those innate characteristics coiled in the double-helix of DNA that Service biologists strive to preserve in the fish. Conservation genetics is at its heart an investment in the future with an eye on the past. Dr. Wade Wilson with the Service’s Southwestern Native Aquatic Resources and Recovery Center in Dexter, New Mexico, knows Gila trout like few others can; he’s a geneticist who can de-code the language. It’s his charge in the conservation of Gila trout to help ensure that the diversity of genetic characters unique in this fish stay in the fish going forward.
Wilson works with another Service facility in New Mexico, the Mora National Fish Hatchery near Las Vegas, New Mexico, where captive stocks of the rare yellow trout are held. Hatchery biologists are fully immersed in Gila trout captive breeding, and it’s done smartly, carefully, through the consult of Wilson.
“We monitor genetic diversity in captive trout to ensure that what we have in the hatchery represents what we have in the wild,” says Wilson. That mixture is essential for the future. “The more genetic diversity that exists among the fish, the better chance those future generations of Gila trout can adapt to changing environments and stressors and diseases in wild populations,” Wilson adds.
“Here’s how we get it done,” explains an enthusiastic Nate Wiese, Mora’s manager and lead fisheries scientist. “Each fish gets a microchip injected just under the skin just like your vet can do for your dog. That chip gives each fish a personal ID, like a social security number. Knowing each fish at an individual level is a first step in securing the future of Gila trout.”
With every captive fish in the hatchery marked as such, biologists take non-lethal tissue samples from the fish, a tiny piece of fin. From there it’s up to Wilson and his staff using leading-edge technology to look deep at each fish—at the molecular level. Wilson will pinpoint individual fishes with the rarest of genetics in the captive populations and suggest what Wiese calls “pair-wise spawns.” It’s akin to arranged marriages but with the express scientific purpose to ensure that the rarest of genetic characters found by Wilson are carried forward in the next generation of fishes. Males and females that differ among various genes make the best partners.
The Gila trout was described by science a mere 65 years ago. Through much of that intervening time—50 years—it had been closed by law to angling as the fish stared at extinction. Its lot improved with conservation and was down-listed from “endangered” to “threatened” in 2006, and opened to fishing a year later. And so it remains, threatened and fishable, despite a welter of catastrophic wild fires—the sort that makes the evening network news broadcast for days on end.
“An integral part of the conservation strategy calls to replicate in the wild the distinct genetic lineages,” says Wiese. It’s a measure of conservation security to give a geographic spread between populations. “But what happens when a massive fire threatens to gobble up the original and replicate populations? The hatchery is the backup.”
Read more about this recovery in the Service's Open Spaces Blog.
Read more about Gila Trout Management in the Desert Exposure
