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Full text release has been delayed at the author's request until July 19, 2029

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Factors Influencing Consumer-Mediated Nutrient Cycling in Freshwater Systems

Sharitt, Carrie Ann
http://orcid.org/0000-0002-5808-7503
http://rave.ohiolink.edu/etdc/view?acc_num=miami1721342357867514

Abstract Details

2024, Doctor of Philosophy, Miami University, Biology.
CHAPTER 1: Nutrient excretion by fish supports a variable but significant proportion of lake primary productivity over 15 years. This chapter analyzes the long-term importance of excretion from gizzard shad for primary production in a midwestern reservoir using a supply:demand (S:D) approach and considers environmental and population variables that best predict the S:D ratio. Gizzard shad excretion supported a variable proportion of phytoplankton phosphorus demand, and it supported more demand during the summer than spring. Stream discharge, temperature, and gizzard shad population biomass best predicted S:D during the spring, while the biomass of the young-of-year best predicted S:D in the summer. CHAPTER 2: Combined influence of parasites and temperature on nutrient excretion rates and body stoichiometry of a freshwater fish. The rates of excretion from fish and the ratios of the nutrients excreted are expected to change as aquatic ecosystems warm. An experiment examined the excretion rates from bluegill under three climate scenarios and a range of natural parasite intensity. Carbon and phosphorus excretion increased with temperature but declined with parasite load, and the C and N concentrations in fish bodies declined with parasite load. CHAPTER 3: Ontogenetic changes in the gut microbiomes of Gizzard Shad and Bluegill and their relationship to nutrient excretion. The microbial communities within the guts of animals contribute to their health, but little is known about how these communities change with development and contribute to ecosystem processes. We conducted an exploratory study to learn about the gut microbiome of larval, young-of-year, and adult gizzard shad and bluegill as well as the relationship between microbiomes and excretion. We found that the two fish species had similar microbial communities as larvae, but the communities were different in the adults. The guts of adult gizzard shad contained taxa that are believed to fix nitrogen as well as several taxa of methanotrophic bacteria. CHAPTER 4: Teaching Nutrient Cycling and Climate Change Concepts Using Excretion Experiments with Common Fish. High school students often learn about nutrient cycling within science courses, but the lessons focus on soil and plants, leaving out the ways in which animals contribute. A study was done with high school students to design and conduct excretion experiments using zebrafish. Students completed pre- and post-surveys, and the study found that student understanding of the role of animals in nutrient cycling and the impact of climate change on nutrient cycling increased. Students also showed improved understanding of science processes.
Michael Vanni (Advisor)
Melany Fisk (Committee Member)
Matthew Saxton (Committee Member)
Roxane Maranger (Committee Member)
Christopher Myers (Committee Member)
María González (Committee Member)
96 p.
Biogeochemistry; Biology; Environmental Science; Limnology; Science Education
excretion; reservoirs; science education; gut microbiome; parasites

Recommended Citations

Citations

  • Sharitt, C. A. (2024). Factors Influencing Consumer-Mediated Nutrient Cycling in Freshwater Systems [Doctoral dissertation, Miami University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=miami1721342357867514

    APA Style (7th edition)

  • Sharitt, Carrie. Factors Influencing Consumer-Mediated Nutrient Cycling in Freshwater Systems. 2024. Miami University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=miami1721342357867514.

    MLA Style (8th edition)

  • Sharitt, Carrie. "Factors Influencing Consumer-Mediated Nutrient Cycling in Freshwater Systems." Doctoral dissertation, Miami University, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=miami1721342357867514

    Chicago Manual of Style (17th edition)

miami1721342357867514
© 2024, all rights reserved.
This open access ETD is published by Miami University and OhioLINK.