Master of Science (MS), Wright State University, 2019, Biological Sciences

The coral reefs within Indonesia's Wakatobi Marine National Park support a high diversity of reef-building hard corals and associated marine fish. Climate change threatens to dramatically affect coral reef ecosystems by altering the interactions between reef fish and the specific microhabitats they depend on for survival. To examine the spatially varied effects of habitat complexity on the community composition and trophic structure of marine fish assemblages, I analyzed fish community and habitat complexity data across reef zones. Habitat complexity metrics were: structural complexity, the percentage of hard coral (HC) cover, HC genera richness, HC genera diversity (Shannon index), and HC growth form diversity (Shannon index). The community composition of fish assemblages was significantly positively related to habitat complexity, reef zones, and reef systems. This study found that the overall direction and strength of relationships between the fish community and coral reef habitat complexity data varies spatially between reef zones. Marine conservation and restoration efforts need to include specific management plans that vary among reef zones based on how varied habitat complexity and fish communities are at local scales.

Committee: Volker Bahn Ph.D. (Advisor); Thomas Rooney Ph.D. (Committee Member); Lisa Kenyon Ph.D. (Committee Member); Leonard Kenyon M.S. (Other) Subjects: Biology; Ecology; Environmental Management; Environmental Science; Natural Resource Management; Oceanography

Master of Science (MS), Wright State University, 2018, Biological Sciences

Macroinvertebrates are important contributors to wetland ecosystems due to their role in decomposition, nutrient cycling, and as a food resource for other organisms. Several studies have analyzed the macroinvertebrate communities in created wetlands, but few have evaluated them in the context of trophic structure in both created and natural wetlands. The objective of this study is to better understand benthic macroinvertebrate community composition and trophic structure in created and natural wetlands. My central hypotheses were that macroinvertebrate communities in created wetlands would have (1) differing composition and (2) less complex trophic structure with shorter food-chain length compared to natural wetlands. Macroinvertebrates and soil cores were collected from five created and two natural depressional marshes. I assessed macroinvertebrate community characteristics such as diversity and composition, and functional feeding group composition. I used stable isotope analysis to determine food-chain length and other trophic metrics. Soil cores were used to determine bulk density, texture, and the C:N profile of the soil in the wetlands. Through a combination of univariate (e.g. ANOVA) and multivariate analyses (e.g. NMDS, PERMANOVA) these conclusions were met: (1) Macroinvertebrate taxa composition differed statistically between wetland types (p= 0.05); (2) FCL did not differ significantly between wetland types. In addition, functional feeding group composition was trending toward significance (p = 0.095), and soils were found to be distinct between wetland types (p= 0.043), with bulk density being a strong driver of that relationship (p= 0.012). These results show that in these wetlands, macroinvertebrate species present are different, however the overall function they provide are very similar between wetland types. The habitat characteristics in created wetlands that are known to quickly develop (e.g. plant community composition) were similar to the natural we (open full item for complete abstract)

Committee: Katie Hossler Ph.D. (Advisor); Yvonne Vadeboncoeur Ph.D. (Committee Member); Volker Bahn Ph.D. (Committee Member); John Stireman Ph.D. (Other) Subjects: Ecology; Entomology; Environmental Science; Environmental Studies