Theses and Dissertations - UTB/UTPA

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Brad C. Henry Jr.

Second Advisor

Dr. Robert I. Lonard

Third Advisor

Dr. Robert J. Edwards


The purpose of this study was to identify aquatic macroinvertebrates living in the vegetated margins of local ponds, to determine their relative abundances, and to construct a rapid bioassessment model. I collected macroinvertebrates seasonally from seven ponds in the Lower Rio Grande Valley. Collection sites included: Moore Airfield, Santa Ana National Wildlife Refuge, and Olmito Fish Hatchery. Twenty-eight samples were sampled and preserved at the University of Texas-Pan American. Seventy-six taxa were identified and were stored as a reference collection. Cluster analysis of the taxa and their relative abundances showed three distinct geographic patterns or regions. These patterns were verified using two additional collections, which formed a distinct primary cluster. A Lower Rio Grande Rapid Bioassessment (RBA) model was constructed using Plafkin's Environmental Protection Agency (EPA) Rapid Bioassessment Protocol m, a reference site, and eight community measures. The Rio Grande RBA can be applied across the region. Results showed eight sampling units as moderately/slightly impaired sites.


Copyright 1997 Anna Maria Navarro. All Rights Reserved.

Granting Institution

University of Texas-Pan American

Included in

Zoology Commons