1. Aquatic Macroinvertebrate Composition Over an Elevation Gradient
Ishmael, Daniel. (2016, Spring). Aquatic Macroinvertebrate Composition Over an Elevation Gradient. Winter Ecology. Mountain Research Station.
Keywords: Boulder Creek, Elevation, Pollution, Nederland, Mayflies, Stoneflies
1.8MB
Daniel Ishmael
Winter Ecology
Spring 2016
CU Mountain Research Station

2. Aquatic Macroinvertebrates
No backbone, visible to the naked eye.
Indicators of water quality and ecosystem health
Variance in composition can tell us something about environment (Clements et al, 2000).
Winter streams and elevation
-Looking at streams in winter can tell how and which macroinvertebrates can inhabit winter waters.
Macroinvertebrates are indicators of stream quality which could differ during winter months.
Ecosystem health= availability of food, lack of pollution, and providing food to other consumers
Resources and stream dynamics could change with elevation and tell us the sensitivity of species to these changes.

3. Will changes in elevation result in changes in density and composition of macroinvertebrates?
Hypothesis: Statistically significant changes in macroinvertebrate composition will occur along an elevational gradient.
Null Hypothesis: There will be no statistical significance of composition between elevations.

4. Methods Sites in Boulder Canyon Collection 1. 8200 Feet 2. 7400 Feet
Tweezers
Sifter
50cm2 samples
3 replications per site
Replications randomly selected via number generator
Limitations of methods: Lack of proper equipment for collection, not large elevation change, pseudoreplication.

5. Results Site 1 Mayfly (Ephemeroptera) Stonefly (Plecoptera)
Worms (Oligochaetes)
Site 2
Mayfly
Stonefly
Site 3
Mayfly
Stonefly

6. Results Invertebrate Composition and Elevation P=0.15
Number of individuals
Elevation (ft)
-Oligochaetes only found in Nederland site
-Mostly mayflies found
-A few eggs (4) and an unidentified larva (1)
-Mayflies and stoneflies varying extraordinarily in size—not recorded for this data set.
Organisms
Fail to reject Null Hypothesis of no relationship between composition and elevation.
Two-way ANOVA test

7. Results About 50/50 Mayfly and Stonefly <2cm May skew data
P = between orders significant
P=0.59 between elevations not significant
Mayflies are scrapers of detritus/algae
Stoneflies are shredders of plant/animal matter
Streams near 2 degrees Celsius along gradient.
Varying composition of rocks/speed of river at replication sites.

8. Discussion Many factors not accounted for (pH, velocity, sunlight)
Mayflies and stoneflies are pollutant sensitive
Presence of Oligochaeta are well known components in streams that experience siltation and reduced flows (Bestgen et al, 1996).
Warm water temperatures have an effect on emergence (Nebecker, 1971)
Further studies in stonefly/mayfly interaction and others.
Further studies: greater elevation changes, water characteristics, bank and inner stream comparison.

9. Conclusions Limitations of study
While no statistical significance, trend may still be present.
Indicators of healthy stream

10. References
Bestgen, K. R., Kondratieff, B., & Miller, M. C. (1996). Fishes, Macroinvertebrates, and Habitat of South Boulder Creek, Colorado, within City of Boulder Open Space Property. Final Report, January, 31. Retrieved from static.bouldercolorado.gov/docs/ 4721_Bestgen_Kevin_Fishes pdf
Clements, W. H., Carlisle, D. M., Lazorchak, J. M., & Johnson, P. C. (2000). Heavy Metals Structure Benthic Communities in Colorado Mountain Streams. Ecological Applications, 10(2), 626– doi.org/ / (2000)010[0626:HMSBCI]2.0.CO;2
Nebeker, A. V. (1971). Effect of high winter water temperatures on adult emergence of aquatic insects. Water Research, 5(9), 777–