Date of Award

2022-08-01

Degree Name

Doctor of Philosophy

Department

Biological Sciences

Advisor(s)

Vanessa L. Lougheed

Abstract

The relatively rare freshwater ecosystems in the southwestern United States serve as biodiversity hotspots, yet they are among the most threatened systems in the world due to human impacts and climate change. Despite their importance to this arid landscape, the aquatic communities of desert wetlands remain relatively understudied. To restore and create new wetland habitats, effluent is becoming a more commonly used water source for these habitats. However, the effects of byproducts within the treated wastewater on these unique systems have not been well studied. In this study, we aim to better understand the factors that drive water quality and macroinvertebrate community composition of wetlands of the US desert Southwest. In addition, we focused on a local, restored wetland (Rio Bosque Wetlands), to better understand how water quality and community assemblages change with the increased use of treated effluent as a water source. Finally, in an effort to increase awareness of habitat conservation and restoration we created an ecology-based virtual CURE (vCURE) that was implemented to non-science majors attending El Paso Community College.Water quality and macroinvertebrate data were collected over three years from 14 different wetland and riparian sites spanning across West Texas, New Mexico, and Arizona. Results indicated that salinity-related variables such as chloride, sulfate, and conductivity were the greatest drivers of environmental variance. Subsequently, nutrients were shown to have the greatest impact on macroinvertebrate communities with wetlands receiving treated wastewater showing a more uneven distribution of functional feeding groups (sites dominated by filter feeders) and lower Simpson Index scores. Increased salinity levels were also shown to correlate with lower Simpson Index scores thus, a decline in macroinvertebrate diversity and evenness. To track the restoration of the Rio Bosque Wetlands, data collected in 2014, before a change in water regime, and data collected after (2016-2019) was used to determine differences in water quality and macroinvertebrate communities. The increased water inputs during the growing season in 2016-2019, established more permanent bodies of water which affected macroinvertebrate communities by allowing taxa with limited dispersal abilities time to build larger populations. Differences in assemblages within the park were also heavily influenced by the increased nutrients associated with effluent water. Overall, Rio Bosque Wetlands is displaying succession patterns similar to those of other, more established desert wetlands flooded with treated effluent water, with a growing community of filter feeders (Chapter 1). As a result, it is suggested that managers of these valuable created aquatic habitats try to find less nutrient-rich water sources, such as groundwater, to enhance the water quality in their sites. With reduced nutrient levels, we would expect to see an increased in sensitive taxa, predators, and collector-gatherers, among others. Though the macroinvertebrate community in created or restored sites, may not resemble those of a natural site due to the use of treated effluent water, these systems provide much needed habitat for aquatic flora and fauna within the desert landscape. While the scientific community largely recognizes the importance the role of ecology plays in habitat preservation and combating the effects of climate change, much of the general population do not. To increase public understanding of preservation efforts for desert wetlands and other at-risk ecosystems, science literacy skills must increase within the community. Course-based Undergraduate Research Experiences (CUREs) have been used to improve science literacy and attitudes for large groups of students. In 2020 the COVID-19 pandemic and stay-at-home orders forced many college courses to switch to virtual learning which led me to create an ecology-based virtual CURE (vCURE). With the Undergraduate Research Student Self-Assessment (URSSA) and the Test of Science Literacy Skills (TOSLS), we investigated the effects of participation in a vCURE on the science literacy skills, attitudes, and perceived gains of non-science majors and El Paso Community College. Our results showed that students were able to improve their overall TOSLS scores and increase their confidence levels in several general science and research-related activities. In open-ended responses, students felt that the course helped them improve skills that would be beneficial to them in the future, including communication, collaboration, and critical thinking. This shows that non-science majors can still benefit from CUREs though they do not intend to pursue a science-related career. This CURE model can be modified to enhance studentsâ?? knowledge of habitat conservation by creating an in-person wetland-themed CURE to further track the restoration of the Rio Bosque Wetlands.

Language

en

Provenance

Recieved from ProQuest

File Size

126 p.

File Format

application/pdf

Rights Holder

Anna Elisa Pina

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