The High Park fire burned over 87,250 acres (136 sq mi), becoming the second-largest fire in recorded Colorado history by area burned. Beyond the damage to person and property, the fire was additionally thought to be devastating as the bulk of the scorched lands drained almost exclusively to the Poudre River. When trees and underbrush burn, there is little organic material left to absorb moisture. In addition, some plants release a waxy substance when incinerated, generating a water-repellent coating and consequently resulting in a one-two punch, exacerbating erosion and increasing flash flooding. A number of rain storms flushed silt and charred debris from the fire zone into the river which remains evident as black streaks line the streambank from the Kelly Flats campground to Lee Martinez Park in town.
The high park fire threatened the Bellevue-Watson hatchery located in LaPorte, prompting an emergency stocking of 72,765 ten-inch rainbow trout into Horsetooth Reservoir, the closest possible refuge. Later, Colorado Parks and Wildlife (CPW) crews turned attention to the Poudre River and began surveying within a few weeks of the fires’ complete suppression on June 30, 2012.
Kurt Davies, the CPW biologist assigned to manage the Poudre River fishery resources, was initially optimistic as the Poudre had almost immediately began the self-repair process by scouring pools and riffles, micro-habitats that are essential to harboring trout and producing aquatic insects. Roughly 20 miles west of Ted’s Place, survey results near the Kelly Flats campground estimated 2,306 adult trout (rainbow plus brown) per mile, a notable increase from 2011 when 1,779 adult trout were estimated per mile. Chad Morgan, a local CPW wildlife officer who routinely interviews anglers on the Poudre River, stated “there has not been a noticeable decrease in angler success through the burn area and below. This spring, most anglers have been catching browns, some decent size ones, with some rainbows here and there.”
Yellowstone National Park conducted a very robust research project that evaluated the Park’s fishery resources following the 1988 fires which burned 793,000 acres (almost 10 times the High Park Fire). The research conducted revealed litle damage to fishery resources and were nondescript despite 36% of the park’s land being scorched. Approximately 100 dead fish were reported in two streams after fire retardant was accidentally dropped on them. Aside from a temporary decrease in a few species of aquatic insects, no long term impact has been observed on aquatic life in any of Yellowstone's rivers or lakes. The results from Yellowstone equates to good news for the Poudre River.
Within the City limits of Fort Collins at Lee Martinez Park, total adult trout declined from a ten-year high of 3,013 trout per mile in 2011 to 1,830 fish per mile as documented during the fall 2012 survey. The numbers in town are a bit deceiving because the annual stocking of rainbow trout near Lee Martinez Park was canceled post-fire because survival was not certain. Taken as a whole, the fire did not appear to have any negative impact on adult trout populations and further evidence of repair was noted this fall as redds were observed within numerous sections of river within the burn zone. A trout redd is an in-river depression created by the upstroke of the female trout’s body and tail, flushing fine sediments (including ash) from river bottom thus exposing clean gravel. The female trout excavates a number of redds, depositing a few hundred eggs in each over the course of the several days she is spawning. Brown trout build these nests during the fall while rainbow trout have likely just completed this task.
Results from this year’s reproduction will not be evident until electrofishing surveys are completed this fall but the key component, adult trout, remain in solid numbers to produce young fish and provide some tight lines. Go Fish Colorado!