The New York Times had a terrific story on Wednesday on the recovery of an endemic trout previously believed to be extinct since the 1940s in Pyramid Lake, Nevada. As I am currently teaching my class, Ecology, Evolution, and Human Health, with its emphasis on adaptation as local process and human-environment interaction, I was happy to see such an excellent story about local adaptation. In a nutshell, the trout was over-fished and also suffered devastating population declines in Pyramid Lake because of predation from introduced brook trout (and other exotic salmonids) and hybridization with introduced rainbows. This is, alas, an all too common story for trout endemics of western North America. A remanent population of Lahontan cutthroats, that were genetically very similar to the original Pyramid stock, was found in a Pilot Peak stream near the Utah border and samples from this population were brought to a USFWS breeding facility in cooperation with the Paiute Nation. It sounds like the breeding/stocking program has been a tremendous success and the Lahontan cutties have now returned to Pyramid Lake. A big part of the story appears to be the intensive management of the main prey item of Lahontan cutties, the cui-ui sucker, which was devastated following the construction of the Derby Dam in 1905.
This was all great news, but the thing that really caught my attention (because I’m currently teaching this class that focuses on adaptation) was the fact that the re-introduced Lahontan cutties have thrived so rapidly:
Since November, dozens of anglers have reported catching Pilot Peak cutthroats weighing 15 pounds or more. Biologists are astounded because inside Pyramid Lake these powerful fish, now adolescents, grew five times as fast as other trout species and are only a third of the way through their expected life span.