My research in coastal Ecuador and the northern Gulf of Mexico (GOM) elucidated differences in value of shallow estuarine habitats for fishes and invertebrates. I focused on mangrove and tidal river habitats in Ecuador, and oyster reef, vegetated marsh edge, and nonvegetated bottom habitats in the GOM. Coastal Ecuador has lost 20-30% of mangrove wetlands over the past 30 years. Such habitat loss can impair the ecological functions of wetlands. In this study I identified the fish community of the remaining mangrove wetland in Rio Palmar, Ecuador. For comparison, an adjacent tidal river without mangroves, Rio Javita, was also sampled. I found that although Rios Palmar and Javita are characterized by relatively low fish-species richness compared to other tropical estuarine systems, they appear to provide important habitat for several economically- and ecologically-valued species. In the GOM, I examined the fish and invertebrate communities of adjacent oyster reef (oyster), vegetated marsh edge (VME), and nonvegetated bottom (NVB) habitats. Three main relationships emerged: 1) Oyster and VME provide habitat for significantly more species (as a measure of richness) relative to NVB; 2) Oyster and VME provide habitat for uncommon and rare species; and 3) Many of the species collected in multiple habitats occurred at higher abundances in oyster or VME habitat. Contrary to the current low value ranking of oyster habitat relative to other estuarine and salt marsh habitats, oyster provides high quality habitat for many species. Understanding how key species utilize estuarine habitats is critical for future conservation and management efforts. My research indicated that VME habitat may provide better foraging options for juvenile pinfish (Lagodon rhomboides), and together with corroborating evidence from other studies, suggest that VME provides a critical nursery function for juvenile pinfish, especially in estuaries where seagrass habitat is sparse or nonexistent. Additionally, I documented that juvenile white shrimp (Litopenaeus setiferus) select for oyster habitat because of higher food availability and not because of refuge needs from predation by blue crabs. Oyster habitat appears to provide a nursery function for juvenile white shrimp. Overall, my research demonstrated that structurally complex habitats, such as mangroves, VME, and oyster provide essential habitat at the community, population, and individual levels.

Thesis (M.S.)--Marshall University, 2003. / Title from document title page. Document formatted into pages; contains v, 91 p. including maps and illustrations. Includes bibliographical references (p. 39).

Our objective was to quantify if macroinvertebrate assemblages in Indiana streams were better predicted from co-occurring fish assemblages or environmental variables. We used Canonical Correspondence Analysis (CCA) with forward-selection of variables to identify significant environmental predictor variables for macroinvertebrate and fish assemblages. A partial Mantel test was used to determine if fish assemblage composition and macroinvertebrate assemblage composition significantly co-vary while controlling for environmental effects. The CCAs resulted in two significant predictors of macroinvertebrate distribution and relative abundance, and four significant predictors of fish distribution and relative abundance. Similarity matrices of fish and macroinvertebrates were significantly correlated in the Mantel (r = 0.22, p = 0.019) and partial Mantel tests (r = 0.23, p = 0.013). Our results suggest that macroinvertebrates respond to local and regional environmental variation, and less to local presence of fishes. / Department of Biology

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 342-348). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 342-348). Also available on the Internet.

Thesis (Ph.D.) in Oceanography--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 138-154).

The relative importance of local, regional and historical processes to patterns of distribution and diversity of lower Mesoamerican (Panama and Costa Rica, LMA) freshwater fishes are examined at two different spatial scales. Biogeographic patterns of LMA freshwater fish communities at the spatial extent of LMA indicate that biological differences among species as well as regional and historical processes are quintessential to explaining the patters of turnover of community composition and species richness across the LMA Isthmus. The study of LMA freshwater fishes permits the inference that ecological interactions among species are not independent of a region's history, suggesting that regional and historical processes probably play an ongoing role in the maintenance of LMA freshwater fish communities. In addition, the study of the natural experiment of the Panama Canal provides a clear demonstration that dispersal, rather than local deterministic processes such as competition and predation, previously set the upper limit of the number of fish species coexisting in local communities. Comparisons of species inventories established prior to Canal construction with contemporary species lists demonstrates a large net increase in species richness of local communities, suggesting that the local communities of the Panama Canal watershed were not saturated.

Relationships between fish assemblage composition and substrate variation is poorly understood in large rivers. Information on fishes occurrence and behavior and substrate variation were examined in field observations for the Middle Wabash River and fine scale artificial streams experiments. The results from field observations suggested strong concordance for variation in abundance of fishes with habitat variation among sites, resulting in a longitudinal river gradient as dominant in the Middle Wabash River. In addition, shifts in fish behavior within artificial stream experiments demonstrated that species-specific habitat selection behaviors were influenced by interactions within a fish assemblage. The combination of artificial stream experiments and field observations can identify fine scale trends that bioassessment surveys cannot tease apart, and highlighting the need to examine species-habitat relationships at more than one scale. / Department of Biology

No description available.

No description available.