Type:Sound

Subject:Upper Arkansas River
Colorado
Fishing
Superfund site cleanup
Superfund sites in Colorado
Wildlife management
Wildlife conservation

Description:Some terms naturally go together like "Colorado Parks and Wildlife" and "world-class fishing." Few would ever add to that list the term “Superfund sites.” That's because Colorado Parks and Wildlife's 42 parks are recreation meccas. Its 350 wildlife areas boast some of the finest wildlife and aquatic habitat in the state. And even in the United States. But they weren’t always so pristine. In fact, CPW's aquatic biologists and research scientists have played a key role in transforming rivers and wetlands dangerously polluted by decades of mining and milling into prime fish habitat by restoring the waterways to their historic unspoiled conditions. They are erasing the dark legacy of gold mining and restoring gold medal fisheries that are known by anglers worldwide and home to threatened or endangered species. And here to talk about the work that took place along the Upper Arkansas River is Eric Richer, Aquatic Research Scientist and Paul Foutz, Senior Aquatic Biologist for CPW’s Southeast Region. [show more]

Type:Text

Subject:Upper Arkansas River
Habitat restoration

Description:Monitoring activities to evaluate restoration effectiveness for the upper Arkansas River Habitat Restoration Project were conducted by Colorado Parks and Wildlife (CPW) and contractors during 2020 and 2021. Efforts were primarily focused on data analysis and publication of results for monitoring targets, including fish populations, riparian vegetation, benthic macroinvertebrates, instream habitat structures, and water quality. Some fish population, benthic macroinvertebrate, riparian vegetation and habitat metrics improved following restoration, although not all metrics have achieved target goals. Significant improvements in Brown Trout Salmo trutta density, biomass and condition were encouraging, but apparent declines in quality trout could be indicative of increased competition or limited forage. The abundance of benthic macroinvertebrates increased, but not to the level of project goals. Woody riparian vegetation increased significantly, and encroachment of riparian vegetation has outpaced bank erosion, which suggests that bank stability has improved and the channel is moving towards dynamic equilibrium. Multiple metrics indicate that ecosystem health within the California Gulch Superfund Site continues to improve. [show more]

Type:Fact Sheet

Subject:Triploid walleye
Contaminants
Fishing
Fact sheet

Description:According to the U.S. Food and Drug Administration, fish are part of a healthy diet, providing lean protein, healthy omega-3 fatty acids, iron, and more vitamin B12 and vitamin D than any other food. Although fish are an excellent source of protein, integration of mercury into lake and stream food webs results in traces of mercury being present in fish, sometimes at levels that present health concerns to people who consume fish regularly. Because mercury levels increase as you move up the food chain (i.e., ‘bioaccumulate’), concentrations are highest in top predators such as walleye. Through monitoring and research, both the Colorado Department of Public Health and Environment and Colorado Parks and Wildlife(CPW) work to help anglers maximize the benefits of consuming fish while protecting themselves and their families from mercury in the environment. [show more]

Type:Text

Subject:Toads

Description:A guide to locating toads

Type:Fact Sheet

Subject:Tiger trout
Fishing
Research
Fact sheet

Description:Many of Colorado’s coldwater lakes contain fish species, such as suckers and minnows, which provide little value to anglers, compete with managed sport fish, and have the potential to reduce water quality. However, these undesirable fish may be valuable prey items. Sterile fish that have the ability to grow to predatory size quickly and eat the unwanted fish could act as a biological control agent and provide a unique fishing opportunity. Being unable to reproduce, sterile fish can be closely managed through stocking and harvest regulations. Tiger trout, a sterile hybrid between male brook trout and female brown trout, have the potential to fill this role. Tiger trout have already been stocked in some Colorado lakes. Our understanding of what tiger trout eat and how well they grow and survive in lakes with different species of undesirable fish remains limited, and should be fully investigated as a management tool. [show more]

Type:Article

Subject:Swift fox
<em>Vulpes velox</em>
Resource utilization function
Conservation translocation
Reintroduction

Description:Swift foxes (Vulpes velox) are endemic to the Great Plains of North America, but were extirpated from the northern portion of their range by the mid-1900s. Despite several reintroductions to the Northern Great Plains, there remains a ~350 km range gap between the swift fox population along the Montana and Canada border and that in northeastern Wyoming and northwestern South Dakota. A better understanding of what resources swift foxes use along the Montana and Canada border region will assist managers to facilitate connectivity among populations. From 2016 to 2018, we estimated the home range size and evaluated resource use within the home ranges of 22 swift foxes equipped with Global Positioning System tracking collars in northeastern Montana. Swift fox home ranges in our study were some of the largest ever recorded, averaging (± SE) 42.0 km² ± 4.7. Our results indicate that both environmental and anthropogenic factors influenced resource use. At the population level, resource use increased by 3.3% for every 5.0% increase in percent grasslands. Relative probability of use decreased by 7.9% and 7.4% for every kilometer away from unpaved roads and gas well sites, respectively, and decreased by 3.0% and 11.3% for every one-unit increase in topographic roughness and every 0.05 increase in normalized difference vegetation index (NDVI), respectively. Our study suggests that, to reestablish connectivity among swift fox populations in Montana, managers should aim to maintain large corridors of contiguous grasslands at a landscape scale, a process that likely will require having to work with multiple property owners. [show more]

Type:Article

Subject:Swift fox
Conservation translocations
Demographics
Habitat fragmentation
Reintroductions
<em>Vulpes velox</em>

Description:The successful recovery of imperiled species is dependent on knowledge of how demographic drivers mediate population growth and expansion. One of the largest species restoration projects has been the reintroduction of swift foxes Vulpes velox to southern Canada, where 947 foxes were released between 1983 and 1997. Swift foxes have since increased and expanded their range into northern Montana (USA), but have experienced a population decline and stall in recolonization over the past 10 years. The objective of this study was to estimate the survival and reproductive rates of swift foxes in northern Montana, which constitutes the southern edge of this population. In addition, we evaluated support for two different hypotheses of how environmental factors and several demographic factors influence survival. Although our length of monitoring was relatively short, we found that adult and juvenile annual survival rates were 54% and 74%, respectively, and fecundity was 0.85. We found the most support for the hypothesis that the percentage of native grassland at the 1-km scale influenced survival and found that survival increased, on average, 2.1% for every 5% increase in grassland. Compared to previous estimates of swift fox population growth immediately following the release, our data suggest the population is currently stable. The long-term successful recolonization and connectivity of swift fox populations in this region will likely be dependent on maintaining large tracts of contiguous grassland. Comparing the estimates of demographic rates among different points in space and time should help managers better understand the population dynamics and inform restoration strategies for recovering populations. [show more]

Type:Fact Sheet

Subject:State Wildlife Areas
State Fish Units
State Trust Lands
Walk-In Access Program
State Parks
Ranching for Wildlife
Fact sheet

Description:Colorado Parks and Wildlife (CPW) offers hunters, anglers, wildlife watchers and other outdoor recreationists a variety of locations to access the outdoors. Through cooperation with private landowners and the Colorado State Land Board as well as through properties and conservation easements owned or managed by CPW, over 2.5 million acres of land are made available to Colorado’s outdoor recreationists. [show more]

Type:Fact Sheet

Subject:Sport fish
Fishing
South canal
Fact sheet

Description:There are over 105,000 irrigation structures on rivers and streams across Colorado, most in fish bearing waters. Fish loss in irrigation canals is known to be a large problem in the western U.S. but the impact on fish populations in Colorado is unknown. The South Canal is an irrigation ditch near Montrose, Colorado that diverts an average of 857 cubic feet per second from March to November from the Gunnison River for agriculture. The construction of a hydropower plant was expected to increase mortality of fish in the canal so an electric fish barrier was installed at the diversion structure in 2012. [show more]

Type:Text

Subject:Sport fish
Fishing
South canal
Research

Description:An electric fish barrier was installed on the east portal of South Canal to reduce fish entrainment associated with the construction of two hydropower plants in 2012. The objective of this study was to monitor fish entrainment and evaluate the effectiveness of the barrier. Three groups of fish were tagged and released upstream of the barrier; fish from the canal, wild Gunnison River fish, and hatchery reared fingerlings. Mark recapture boat electrofishing was completed and population estimates were made with the Huggins Closed Capture model using fish length to model capture probabilities. The study reach contained 2,994 ± 1,043 fish (>150 mm) in October 2011, 1,764 ± 279 in October 2013, 1,224 ± 239 in July 2014 and 1,900 ± 379 in October 2014. Fish population estimates have declined after the electric barrier, significantly at the 95% level for brown trout but not for rainbows. A total of 288 tagged fish less than 300 mm and four fish greater than 300 mm were recovered below the barrier, representing 1.3% of all tagged fish. The electric barrier appears to meet its objective and successfully exclude larger fish from the study reach, but not smaller age 0, age 1, or age 2 trout. The entrainment, growth and survival of smaller fish maintains a stable population of fish in the canal, but fewer entrained mature fish is likely a benefit to the fish population of the Gunnison River. Further study is needed to evaluate if smaller adult trout can be successfully excluded by the electric barrier with operational modifications. [show more]