Sunday, January 11, 2009

Trout slayer

Caution: The following subject may be controversial!

During the summer of 2008 I participated in a removal project in the High Sierra to battle the forces of biotic homogenization and restore habitat for the endangered mountain yellow-legged frog. 'Twas a grueling job in one of California's most breath-taking wilderness areas. Below is a picture of my work commute to a lake basin at 10,000 feet where I spent the better portion of July and August removing non-native rainbow trout. The purpose of removing the fish is to restore the lakes to their natural condition (a.k.a. fishless) for the benefit of the frogs. The fish can decimate frog populations by eating the tadpoles and out-competing the survivors for food.

Many people that I met in the area were perplexed by the project. At first, when I was asked what I was doing in the back country I would say that I was conducting an aquatic restoration project and studying predator-prey interactions. Then an onslaught of questions followed to my dismay and forced me to explain the part about 'removing' the fish. "Well, whatdya mean yer taking the fish out?" questioned one avid fly-fisherman. I tried my best to explain the ecological significance of frogs in the Sierras. They're endangered, currently numbering at 5% of their historical population, and are what ecologists call an 'indicator species,' because if the habitat is disturbed, then their population will respond by declining, which indicates poor environmental conditions. The S.N. yellow-legged frog is also subject to stressors such as climate change and a rampant Batrachochytrium dendrobatidis or "chytrid fungus" that has deleterious effects on the remaining populations of frogs in the Sierra. 

Most accounts written by John Muir describe the constant chirping of frogs at high-elevation lakes. (They were the most abundant animal in the Sierra, as it turns out). For anglers this usually wasn't much of an argument, however, because most of them like to think there are untouched fishing oases that meet every fishing adventurer's dream. What did I want to say? "Dude, I'd like to see you carry your fat *&%^#@! self over that pass with fishing tackle and a case of beer... don't worry about it..."
Note: one time an man around 70 years old told me that he planned on a visit to our site with his shotgun so he could shoot a frog; yes... shoot... a... frog.

Alas, the ardent fishermen are only a symbol of the widespread reverence of harvestable resources in our wilderness areas. What purpose do frogs serve, anyway? Trout don't naturally occur in the Sierras? Wait, don't you like fish? And the occassional question: how do you transport the fish out from the lakes?

These are all completely valid questions. It is surprising when one learns that historically the only fish to have evolved in the Sierra is the southern-sierra golden trout (Oncorhynchus mykiss aguabonita), which is also facing extirpation by the introduced brook trout. Yes, I love fish, but I am also dedicated to habitat restoration, conservation and well, hey, I still spent the whole summer with fish... even if... well, let's just rip the band-aid off if you haven't already realized that most fish you see in these pictures were only moments from the cold touch of a hunting knife. Mmm, makes for some good eatin's out in the back country!

See, as a management strategy, the fish were pushed out of planes into the high-mountain lakes to create recreational opportunities for anglers. And yes, there are various studies that demonstrate the success of removing non-native trout from high-elevation lakes to allow the amphibian populations to re-colonize the area. 

If you want to read scientific papers about the subject, I suggest looking up peer-reviewed journal articles available on google scholar. 

Anyway, I spent 10 days field 'tours' in the wilderness with one other crew member, living in my tent and out of my backpack. During my five days off I stayed in a tent cabin and often drove to my uncle's condominium in Mammoth Lakes for showers, comfortable beds, and yes, restaurant food. It's hard eating well for 10 days when you have to carry everything with you 20 miles into a project site! 

No comments:

Post a Comment