Undergraduate Honors Theses

Thesis Defended

Spring 2019

Document Type


Type of Thesis

Departmental Honors


Ecology and Evolutionary Biology

First Advisor

Dr. Pieter Johnson

Second Advisor

Dr. Barbara Demmig-Adams

Third Advisor

Dr. John Pitlick


The community composition of different benthicmacroinvertebrates can be used as an indicator of environmental conditions. Benthicmacroinvertebrates are small organisms that lack a backbone (invertebrate), live on the bottom (benthic), and are visible with the naked eye (macro). To better understand the community structure of benthicmacroinvertebrates communities and how they respond to changing environmental conditions, 53 benthic macroinvertebrate samples were collected over the summer of 2018 from three alpine lakes in the Green Lakes Valley, CO. Benthicmacroinvertebrates were sampled from the shoreline, inlet (inflow of water), and outlet (outflow of water) of each sampled lake, within lake variables (surrounding vegetation, temperature (C°), rock size (cm3), nitrate (mg/L,) pH, and percent dissolved oxygen were also measured every time benthicmacroinvertebrates were sampled. The results of this study suggest that lake identity and duration of ice-off period are major driving forces of benthic macroinvertebrate taxonomic richness and density when compared to within lake level variables. Considering that aquatic alpine environments are experiencing average sooner ice off times,benthic macroinvertebrates communities are expected to change in future years, establishing a need for future studies of benthic macroinvertebrates in changing alpine environments.