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

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.

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.

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.

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

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

Results About 50/50 Mayfly and Stonefly <2cm May skew data P = 0.017 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.

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.

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

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 https://www- static.bouldercolorado.gov/docs/ 4721_Bestgen_Kevin_Fishes-1-201307091154.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), 626–638. http:// doi.org/10.1890/1051-0761(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), 777–783. http://doi.org/10.1016/0043-1354(71)90100-X