Life Sciences Commons^™

Decay Of Macroalgae And Leaves And Their Relation To Detrital Food Webs, Megan E. Grandinetti

Masters Theses & Specialist Projects

This project addressed if decaying macroalgae and leaf detritus play a major role in the detrital pool of a 7th-order karst riverine system. Decay rates, macroinvertebrates colonization patterns, and change in δ13C values of Cladophora, Platanus occidentalis, and a mix of Acer negundo and A. saccharinum were tracked during summer and autumn months for portions of multiple years.

Packs of air-dried Cladophora, Acer, and P. occidentalis were placed in mesh bags and put in groups (n=4) in wire baskets. Seven baskets were submerged in riffle (0.5 m) and deeper run (2 m) habitats. Benthic organic matter was collected with each …

Epiphytic Diatom Community Structure In A Karst Riverine System, Gregory John Barren

Masters Theses & Specialist Projects

The goal of this study was to assess the epiphytic diatom community structure of two host species along a karst gradient in the upper Green River, Kentucky to a gain a better understanding of the role of diatoms in the food web. The host species studied were Podostemum ceratophyllum and Cladophora. Percent cover of P. ceratophyllum and Cladophora were quantified in the four study reaches. The host species were sampled near-shore and mid-channel in each reach in September and October of 2013. After diatoms were extracted from the host and enumerated the density and diversity were quantified. Twelve genera were …

Corbicula Fluminea Food Web Ecology: An Experimental Transplant Approach In A Karst Riverine System, Autumn Smith

Mahurin Honors College Capstone Experience/Thesis Projects

The Asiatic clam Corbicula fluminea is a filter-feeding habitat generalist. Carbon isotopic composition (δ13C) of C. fluminea body tissue was compared between reaches of Kentucky’s upper Green River that differed in Cladophora growth. Corbicula fluminea from an upstream reach with little Cladophora was translocated to a downstream reach with high Cladophora levels. Individuals from both reaches were placed in mussel silos in the same downstream reach in autumn 2012 and again in 2013 for 77 and 119 days, respectively. Flow during 2012 consisted of no high flow events until late autumn. Flow patterns in 2013 were consistently higher and more …

Trophic Dynamic Interactions In A Temperate Karst River, Elizabeth Malloy

Masters Theses & Specialist Projects

Surface streams in karst landscapes are often characterized by high nutrient levels due to incomplete filtration through series of innumerable, below-ground conduits. Seasonal growth of the filamentous alga, Cladophora, is typically associated with nutrient-rich waters. This research compared macroinvertebrate food web structure between riverine reaches with contrasting underlying karst topography, nutrient levels, and Cladophora cover during summer 2012 and autumn 2013. Recent work in these reaches found a high correlation between Cladophora cover and nutrient content, particularly nitrate. Four questions were addressed during this study: 1. Do longitudinal trends in algal and consumer δ13C values relate to decreased DIC availability …

The Ecological Roles Of Podostemum Ceratophyllum And Cladophora In The Habitat And Dietary Preferences Of The Riverine Caddisfly Hydropsyche Simulans, Brenna Tinsley

Mahurin Honors College Capstone Experience/Thesis Projects

The net-spinning caddisfly Hydropsyche simulans can be a common inhabitant of shallow reaches in riverine systems, and is easily the most common hydropsychid in the upper Green River, Kentucky. This study was performed in summer 2011 and focused on two main questions: 1. Do the larvae of the riverine caddisflies H. simulans and Cheumatopsyche preferentially inhabit dense patches of P. ceratophyllum compared to bare substrates in the upper Green River?, and 2. Do larvae of H. simulans and Cheumatopsyche consume the filamentous alga Cladophora during the annual late summer algal bloom in the upper Green River? Densities of both hydropsychid …