Scientists, anglers take hard look at catch-and-release policy for Blue
January 10, 2007
Aspen, CO ColoradoSUMMIT COUNTY – While the Colorado Division of Wildlife will most likely endorse catch and release as the policy for fishing the Blue River below Green Mountain Reservoir, the discussion illustrates the delicate balance between science, morality and politics.While the public has widely supported catch and release, which now stands as the agency’s preferred alternative, an aquatic biologist with the agency said science provides evidence that some limited harvest of fish could have long-term benefits for the fishery.And field-level CDOW managers also said a constituency that was under-represented at the anglers’ roundtables would support some harvest of fish.”We collected the scientific data … for the best management of the resource,” said Billy Atkinson, the Steamboat-based biologist who evaluated the numbers from electro-shocking studies last summer.Atkinson acknowledged CDOW’s recommendation for catch and release is based on social values, as well as scientific data, and emphasized that he’s not pushing for the agency to change course.But Atkinson added that research showed some limited harvest of brown trout in the stretch of river could boost rainbow trout numbers. Both catch and release as well as the limited-take alternative would help sustain the fishery in the long run, Atkinson said.Continued monitoring in the reach will help determine how well the rules are working, Atkinson said.”There’s a few different ways to skin a cat,” said Sherm Hebein, CDOW’s senior aquatic biologist for the agency’s west regions. Hebein agreed with Atkinson’s assessment of the research. Some limited harvest of smaller brown trout could reduce competition for food, thus boosting the size of remaining fish and potentially helping the rainbow trout population.But Hebein said he is satisfied with the agency’s recommendation for catch and release.Trout Unlimited’s take”There are some places where we actually support some limited take,” said Colorado Trout Unlimited director Dave Nickum, citing the Gunnison River as one of those spots. Allowing some harvest of fish is a valid management tool, depending on the objective, he said.On the Blue River reach in question, Nickum said his nonprofit coldwater fishery conservation group was comfortable with both the preferred catch and release option and the limited-take alternative.Nickum also said social factors are a factor, as well as the question of which regulations are easier to enforce. The simpler catch and release rule is clear-cut and doesn’t require field managers to measure fish, for example. The trick is finding a balance that allows a sustainable take, he said.The push for catch and release rules on the Blue may reflect a wider cultural shift, Nickum said, explaining that it wasn’t too long ago that the Division of Wildlife faced strident opposition to catch and release regulations.”The culture of catch and release has really taken hold,” he said. “I think it’s the idea that a good fish is too valuable to just be taken once.”Mix and match managementThe Division of Wildlife uses limited take regulations in other prime fishing waters to try and balance the populations of different species, as in reaches of the Fryingpan River near Aspen and the Gunnison River.Atkinson said the fishery below Green Mountain Reservoir differs from other tailwater areas of rivers in a few significant ways.For one, there are no mysis shrimp in that stretch of river, a key food source that helps sustain the thriving fishery in the Blue River below Dillon Reservoir.Additionally, releases from Green Mountain Reservoir have been via surface spills the last three years, due to periodic turbine maintenance in the hydropower plant. The warmer water spilling into the river at temperatures between 64 and 67 degrees has contributed to the high trout population.But when the maintenance is done, the water released downstream will be much colder, coming from a depth of more than 150 feet, Atkinson said.The combination of cold water and lack of mysis shrimp could impact the growth rate of the trout.”It’ll be interesting to see how it plays out,” Atkinson said, explaining that the numbers showed relative weights of the larger fish in the system “sliding down.”Allowing some limited take in the river could reduce the competition for food, allowing the remaining fish to thrive.”Basically, it’s fewer mouths to feed,” Atkinson said.The Colorado Wildlife Commission will discuss the Blue River fishing regs at its regularly scheduled Jan. 11 meeting in Denver. Call (303) 291-7208 or go to http://wildlife.state.co.us/WildlifeCommission/ for more information.