Dissertation/Thesis Abstract

Environmental impacts on aquatic diversity: Evaluating Macro-invertebrate Communities in the Meramec River
by Siech, Katie, M.S., Southern Illinois University at Edwardsville, 2016, 92; 10249122
Abstract (Summary)

River ecosystems exhibit dynamic shifts corresponding to inputs of matter and the transfer of energy through trophic levels (Vannote, 1980; Cummins, 1974). However anthropogenic sources can disrupt these systems by altering the flow regime, thermal regime, nutrient inputs, refuge, and ultimately the flora and fauna that live within the river channel (Vannote, 1980; Cummins; 1974; Allan, 2004, P. 257–284; Richards, 2004, and others). Along the Meramec River, anthropogenic land uses include urbanization, row-crop agriculture, and most notably, hay/pasture agriculture for cattle grazing (Blanc, 1998). Hay/pasture agriculture along river channels has shown to disrupt macro-invertebrate communities through increasing erosion and sedimentation (Kyriakeas, 2006; Moore, 2005; Harding, 1999; Hall, 2003 and others). Ecologists can understand these changes by evaluating biological criteria, such as macro-invertebrate diversity and how spatial scale as well as chemical and physical variables correlate to various diversity metrics (Sarver, 2011; Klemm, 1990; Justus, 2010; Barbour, 1996). This research attempts to ascertain correlations between macro-invertebrate diversity and land use types along a longitudinal gradient, across multiple scales within the Meramec River. Specifically, three questions are addressed: 1) How does macro-invertebrate diversity correlate to hay/pasture agriculture within a 100 m (~328 ft.) riparian corridor of the Meramec River? 2) How does macro-invertebrate diversity change longitudinally along the Meramec River? And 3) How do physical and chemical parameters correlate to macro-invertebrate diversity and land use within the river channel? Nested ANOVAs and post-hoc analyses were used to discern differences between groups in the river channel. Furthermore, a correlation matrix between continuous variables was analyzed to determine collinearity between abiotic variables in the river channel. A one-way analysis of variance for each parameter was conducted to determine differences in water quality between river sections. Within the Meramec River, diversity calculated using the Simpson’s Diversity Index (Simpson, 1949) does not exhibit significant difference at any spatial scale or among different land use types. However, macro-invertebrate richness shows significant differences between sections of the Meramec River (sub catchment scale), and the lowest richness is observed in the lower section (p < 0.05). An analysis of functional feeding group shows nearly significant differences in predators and filterers, with the highest abundance of each group in the lower section. Furthermore, of the abiotic parameters collected, only electrical conductivity, pH, turbidity, and temperature displayed significant differences between river sections (p < 0.05), indicating watershed properties are the biggest predictor of macro-invertebrate diversity and water quality in the Meramec River. These findings suggest that the lower section of the Meramec River demonstrates the greatest need for focused efforts in conservation, especially as multiple land use types surround the Meramec River in this region.

Indexing (document details)
Advisor: Martinez, Adriana
Commitee: Shouse, Michael, Theodorakis, Chris
School: Southern Illinois University at Edwardsville
Department: Environmental Sciences
School Location: United States -- Illinois
Source: MAI 56/03M(E), Masters Abstracts International
Subjects: Biology, Geography, Environmental science
Keywords: ANOVA, Agriculture, Diversity, Freshwater, Macro-invertebrates, Meramec
Publication Number: 10249122
ISBN: 978-1-369-53883-0
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