The Alvord cutthroat trout was considered extirpated by hybridization with rainbow trout that were introduced to its home waters of Trout Creek, Oregon and Virgin Creek, Nevada.
In the mid-1980’s there was a flurry of excitement over a remnant of the Alvord cutthroat trout found in Virgin Creek (and even as late as the year 2000 it looked like a remnant still remained in Virgin Creek). Yet, sadly, due to a number of factors, these trout were lost to history — and the Alvord cutthroat trout generally became considered to be truly extinct.
Yet, in 2006 Dr. Robert Behnke and ODFW personnel identified a remnant of phenotypical Alvord cutthroat trout in an isolated remote SE Oregon stream. In a 2007 Trout Magazine article Dr. Behnke published the story about the finding of these phenotypical alvordensis; and his thoughts/recommendation as to how it might be possible to preserve this remnant.
This visible remnant of alvordensis would ultimately lose the phenotypical expression that they were still manifesting (through hybridization with other trout strains that ODFW had been introducing into this small stream). Dr. Behnke suggested taking the best phenotypes for transplant into a suitable, yet uninhabited, stream to save the remaining characteristics and establish these phenotypical Alvord trout as a self-populating ‘Alvord’ remnant with all of the outward characteristics of the Alvord cutthroat trout dominant in their appearance.
Typically “once hybridization starts, the next generation will start to form a hybrid swarm, and the genes will be irreversibly mixed in the population within the following generation, and (it) will approach equilibrium in less than a half dozen more generations (30+ years).” 1
In the native Alvord cutthroat trout systems of Trout Creek, OR and Virgin Creek, NV – it was such a few years after the introduction of Rainbow trout that the majority of Alvords of each system vanished from view as introgression destroyed their visible characteristics.
However it is evident that the populations in ***** Creek have not approached equilibrium since specific strains are still clearly identifiable, and are often found in population clusters. There is also some indication that selective spawning by these relict alvordensis may have slowed the rate of introgression with other cutt strains. See Late July, Some Still Spawning
In fact the introgression only first began “in 1957 with Lahontan cutthroat trout collected from Willow Creek in 1955 and reared at Wallowa Hatchery” (Oregon Native Fish Status Report). As most fisheries biologists will acknowledge—small hatchery trout tend to have a low initial survival rate. Since these (and latter hatchery trout) were inevitably planted in the most accessible locations of the ***** Creek system — and the alvordensis population would have had a “head start” in saturating the whole system — these latter introductions most likely initiated a sporadic and limited introgression for a period of years after release.
Yet such a situation cannot go on forever. It is plain to see that a genetic “time clock” has been in process for decades—and now only in this narrow window of opportunity can this remnant of phenotypical Alvord cutthroat trout be rescued and restored. If we desire the streams of tomorrow to safeguard the distinct rugged living beauty of this rare survivor of the desert then now is the time to take action in behalf of this remnant of Alvord trout.
Plus, an expression of urgency: Over 10% of the total time that hybridization has been in process (since the introduction of other trout strains) has passed since SE Oregon Fisheries Biologists were apprised of this situation by Dr. Robert J. Behnke in 2006. Fifty-five years ago, the first of known nonnative trout began to be introduced into this stream by ODFW.
Those who have frequently been on the system—assert that the ratio of the optimal Alvord cutthroat trout phenotypes, in comparison to other cuts strains, seems to be on the decline.
Waiting until tomorrow may simply be too late to preserve the best remaining phenotypes.
