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The Yellowstone Fly Fishing Volunteer Program (YFFVP) is a collaborative effort by the National Park Service and Yellowstone Forever that utilizes “fly fishing for science” as a way to aid park biologists in their efforts to identify, maintain, enhance, and restore native fish populations within Yellowstone National Park.  Each year, volunteers, directed by fisheries biologists and led by the program’s coordinator, hike into Yellowstone’s rivers, creeks, lakes and ponds to sample and record data about the fish populations that reside within them.  This “sampling” is conducted by fly fishing. 


The program lasts approximately six weeks, usually beginning in mid-July and extending throughout August, sometimes into September. Each morning, Monday through Friday, the YFFVP coordinator meets with that day’s volunteer anglers at an established location in Gardiner, MT.  The group boards a vehicle and then travels with the coordinator to the predetermined study area.  These groups, typically of four or five volunteer anglers, have been chosen to participate by a lottery system after submitting a formal application (see How You Can Help).  Most participate over a two or three day period. 


Once the team reaches that day’s planned study-water, safety issues are discussed, and then the fishing begins.  After a fish is caught, it is measured and keyed to species using specific guidelines outlined by park biologists.  Photos may be taken and the location in which the fish was caught is recorded with a GPS.  The fish may be implanted with identifying tags and/or scanned to see if they were previously tagged.  Fin clips to analyze DNA may be obtained.  Nonnative fish in the study areas are usually dispatched, and native fish are released.  After a 6 to 8 hour day, the team re-boards their vehicle and returns to Gardiner.  Each week, the information collected is passed on to biologists who are overseeing the project.

Why is this work Necessary

Over 130 years ago, well-intended government agencies began transplanting nonnative fish into Yellowstone National Park.  Before Europeans arrived on the continent, the only native “sportfish” in the park’s rivers, streams, and lakes were westslope and Yellowstone cutthroat trout, grayling, and mountain whitefish.


Rainbow trout from the Pacific coast, brook trout from the Eastern U.S., brown trout (originally) from Europe, and lake trout from the Great Lakes region were all stocked in various park waters.  Nearly all of these fish were introduced to provide sport for visiting anglers.  Some park waters were naturally devoid of trout before the stocking began.  But most were occupied by native fish who had evolved to live in their home waters over thousands of years. 


These newly introduced, nonnative fish were able to outcompete the park’s trout, grayling, and whitefish, causing steep declines in their populations and often their total disappearance.  This continues today, though no nonnative fish have been stocked in the park since the 1930’s.  The introduction of lake trout to Yellowstone Lake remains a catastrophic blow for the world-renowned Yellowstone cutthroat which reside there. 


The lake was long-considered a Yellowstone cutthroat strong-hold, an impenetrable bulwark for the specie’s survival in the face of a warming planet and other threats.  But, today, that no longer remains the case.  At their peak, the lake trout in Yellowstone Lake consumed up to 90% of the native fish’s spawning population, though efforts spearheaded by the National Park Service have now stemmed the tide of destruction, and the Yellowstone cutthroat fishery is improving. 


Outside the lake, rainbow trout and their offspring are perhaps the greatest threat to the long-term survival of native cutthroat living in the park’s rivers and creeks.  Rainbow trout are impacting park fisheries in a different way than the lake trout: by interbreeding with cutthroats and producing a hybrid fish known to anglers as a cuttbow.  Cuttbows are taking over parts of the Lamar River and Slough Creek (and other waters), threatening to destroy these world-famous cutthroat fisheries which have existed for thousands of years. 


Native fish, including Yellowstone and westslope cutthroat trout, were eaten by native Americans in the Yellowstone region.  Later, Lewis and Clark (outside YNP) encountered these fish.  The park’s first explorers relied upon cutthroat trout for their survival.  Perhaps Yellowstone National Park’s greatest legacy is being one of the only places in North America that retains nearly all of its pre-European settlement’s natural ecosystem.  If we lose pure Yellowstone cutthroat trout, we lose this legacy, and part of what makes the park so special.  This ecological tragedy was created by a desire for “better” fishing in the park.  It’s wonderful to think that today’s fly fishers can now work to help rectify that.   

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