The effect of the Grand Ditch on the abundance of benthic invertebrates in the Colorado River, Rocky Mountain National Park
Abstract
AbstractWe investigate herein the hypothesis that there is a significant relationship between bed particle mobility and benthic invertebrate abundance in the gravel‐bed channel of the upper Colorado River in Rocky Mountain National Park. A large diversion channel called the Grand Ditch normally diverts a significant portion (∼50%) of the annual snowmelt runoff from the watershed northward out of the basin. In May 2003, a ∼30‐m section of the ditch was breached, contributing substantially to the magnitude and duration of discharge in the Colorado River until the ditch breach was repaired in July of that year. As a result, all grain sizes in the river channel were mobilized, which contrasted sharply with the minimal gravel transport experienced during the exceptional drought of the previous year. Benthic macroinvertebrates were collected in the field using a Surber sampler at the same six locations for both years, and the number of individuals of the orders ephemeroptera (mayflies), plecoptera (stoneflies), trichoptera (caddisflies) and diptera (e.g. chironomids) was counted in the laboratory. The total number of individuals was 240% higher in 2003, and the proportion of mayflies in the samples increased from 25% in 2002 to 40% in 2003. In 2003, samples were also taken immediately upstream and downstream of a large flow obstruction in the channel in order to further isolate the relative importance of sediment transport against other variables affecting the stream habitat. Numbers of individuals for all taxa collected (particularly ephemeroptera and plecoptera) were nearly an order of magnitude higher at the upstream site than at the downstream, protected location. These results have important implications for the ecosystem management of streams within Rocky Mountain National Park and elsewhere. Copyright © 2008 John Wiley & Sons, Ltd.
Local Knowledge Graph (2 entities)
Related Works
Items connected by shared entities, co-authorship, citations, or semantic similarity.
Effects of single and terraced beaver ponds on benthic macroinvertebrate communities
Effect of a reduction in mountain stream flow on the diversity and quantity of benthic macroinvertebrates and the abundance of algae
Differences in macroinvertebrate community structure in streams and rivers with different hydrologic regimes in the semi-arid Colorado Plateau
Estimating densities of larval Salmonflies (Pteronarcys californica) through multiple pass removal of post-emergent exuvia in Colorado rivers
Rainbow trout diet and invertebrate drift data from 2012-2015 for the Colorado River, Grand Canyon, Arizona
Rainbow trout diet and invertebrate drift data from 2012-2015 for the Colorado River, Grand Canyon, Arizona
Some Factors Historically Affecting The Distribution and Abundance of Fishes In The Gunnison River
Minimum Flow Recommendation for Passage of Colorado Squawfish and Rasorback Sucker in the 2.3 Mile Reach of the Lower Gunnison River: Redlands Diversion Dam to the Colorado River Confluence
Effect of Keystone Mine Effluent on Colonization of Stream Benthos
Cited 15 times
References (40)
40 references to works outside the Knowledge Hub