Biology ETDs

Publication Date

Spring 4-15-2023


Aquatic and riparian food webs are inextricably linked. In deserts, they provide critical energy subsidies to surrounding terrestrial food webs, but these vital subsidies are not guaranteed; streams in arid lands are especially sensitive to perturbations. In this dissertation, I investigated the role of an oft-cited threat to stream communities in the lower Colorado River basin: non-native crayfish. I contributed to methodologies in passive integrated transponder use and length-weight relationships in crayfish to aid future research. I leveraged stable isotope analysis of δ15N, δ13C, and δ2H to understand crayfish role in the food webs. Lastly, I used mesocosms and reach-level density manipulations to understand crayfish influence on lateral subsidies under varying densities. This dissertation contributes to scientific understanding of omnivore behavior in food webs and provides important information to the management agencies dedicated to preserving biodiversity and ecosystem functioning of our irreplaceable aquatic natural resources.

Project Sponsors

U.S. Fish and Wildlife Service, University of New Mexico Graduate and Professional Association, Chiricahua Desert Museum, Southwestern Association of Naturalists, University of New Mexico Center for Stable Isotopes




invasive species, length-weight relationships, mesocosms, northern crayfish, stable isotopes, stream ecology

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Thomas F. Turner

Second Committee Member

Scott L. Collins

Third Committee Member

Keith B. Gido

Fourth Committee Member

Seth D. Newsome