Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 135-152). Also available on the World Wide Web.

Mangrove habitats are considered as the ideal fish nursery as they are known to increase the growth and survival of juvenile fishes by providing enhanced food availability and protection. However, most studies have focused on tropical mangroves with a few recent warm temperate studies finding conflicting results. Furthermore, the nursery value of South African mangroves to fishes remain understudied in subtropical areas, while warm temperate mangroves are yet to be evaluated. This study aimed to assess whether mangrove presence leads to any advantage to the larvae of an important estuarine resident fish species, Gilchristella aestuaria, by comparing the food patch quality of South African warm temperate mangrove and non-mangrove estuaries. Results indicate that larvae fed primarily on the dominant prey species, Pseudodiaptomus hessei, Paracrtia longipatella, and Acartiella natalensis. However, postflexion larvae consumed more of the larger species, P. hessei, within the two mangrove estuaries (16.09 %V in Nahoon and 13.79 %V in Xhora) than the two nonmangrove estuaries (12.20 %V in Gonubie and 7.05 %V in Qora), despite other prey species occurring at similar densities. Results indicate that mangrove habitats acted as sediment sinks, slightly reducing the turbidity of these estuaries which resulted in postflexion larvae actively selecting larger, more nutritious prey, which in turn, significantly increased their individual instantaneous growth rates (0.11 ± 0.21 Gi) when compared to postflexion larvae in non-mangrove estuaries (0.09 ± 0.12 Gi). This study found that mangrove presence was significantly related to postflexion larval densities when coupled with abiotic (such as temperature and turbidity) and biotic factors (such as predator-prey interactions). Understanding the spatial and temporal dynamics, predator-prey interactions as well as the growth and survival of G. aestuaria is particularly important as they are key zooplanktivores that are prey to other species in estuarine food webs.

Nip Hin Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 132-150). / Abstracts in English and Chinese. / Declaration --- p.i / Abstract --- p.ii / Acknowledgements --- p.vi / Table of Contents --- p.vii / List of Tables --- p.ix / List of Figures --- p.xi / Chapter Chapter 1 --- General introduction --- p.1 / Chapter Chapter 2 --- Fish communities in the shallow soft shores of eastern Hong Kong / Introduction --- p.4 / Materials and methods --- p.7 / Results --- p.11 / Discussion --- p.21 / Chapter Chapter 3 --- Mangroves as fish nurseries: a case study in subtropical southeastern China / Introduction --- p.33 / Materials and methods --- p.37 / Results --- p.41 / Discussion --- p.113 / Conclusion --- p.124 / Chapter Chapter 4 --- General discussion --- p.126 / Chapter Chapter 5 --- General conclusions --- p.131 / References --- p.132

Thesis (Ph. D.)--University of Hong Kong, 1995. / Photocopy of the original. Includes bibliographical references (leaf 130-157).

The main objective of this research was to analyze how well my proposed Foundation Species Interaction model explained the benthic communities found on red mangrove (Rhizophora mangle) prop roots. This research investigated the connections between the primary foundation species (mangroves), the dominant secondary foundations species (oysters, sponges, and barnacles), and the resulting biodiversity in order to understand the temporal and spatial variability of the ecosystems at different community levels. Chapter 1 was dedicated to explaining my change in ecological theory, the Foundation Species Interaction model. The interactions included in the model between the foundations species that were examined were the mutualistic (+, +), commensal (+, 0), and parasitic (+, -) interactions. Chapter 2 focused on exploration of the mangrove ecosystem in Southeast Florida and establishing where the secondary foundation species and prop root epibionts where found along the latitudinal gradient. The survey investigated the connections between mangroves, the dominant secondary foundations species (e.g. oysters, sponges, and barnacles), and the resulting biodiversity to understand the temporal and spatial variability of the ecosystems at different community levels. Chapter 3 was dedicated to testing the Foundation Species Interaction model’s ability to predict the biodiversity along the latitudinal gradient of the survey. The difference in mangrove prop root communities were largely explained by where the communities laid along the latitudinal gradient and by secondary foundation species presence. The shift from one foundation species to another had sizable effects on biodiversity. Chapter 4 combined the Foundation Species Interaction model with the established predation hypothesis and tested their abilities to explain biodiversity along the latitudinal gradient. This allowed for shifts in community structure to be examined for top-down and bottom-up influences. Predation effects changed along the latitudinal gradient, as the predation effects changed so did the effects of each of the individual foundation species. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

published_or_final_version / Ecology and Biodiversity / Doctoral / Doctor of Philosophy

Plant interactions (e.g., competition, facilitation) are critical drivers in community development and structure. The Stress Gradient Hypothesis (SGH) provides a predictive framework for how plant species interactions vary inversely across an environmental stress gradient, predicting that facilitation is stronger with increasing levels of stress. The SGH has been supported in numerous ecosystems and across a variety of stress gradients, but recent research has demonstrated contradictory results. These discrepancies have led to SGH revisions that expand its conceptual framework by incorporating additional factors, such as other stressor types and variations in species life history strategies. In this dissertation, I examine a further modification of the SGH by proposing and testing a Multiple Stress Gradient Hypothesis (MSGH) that considers how plant interactions vary along a continuous gradient of two co-occurring stressors using mangrove and salt marsh communities as a case study. In Chapter 1, I outline the predictive framework of a MSGH, by creating a series of predictions of species interactions. The components of the MSGH predict that stressors of similar types (e.g., resource and nonresource) will have similar effects and be additive. On the other hand, varying species life history strategies and life stages will lead to extremes of plant interactions. In Chapter 2, I performed a series of experiments to test the various components of the MSGH. In Chapter 3, I performed a large-scale observational study to test whether multiple co-occurring stressors altered the cumulative effects on plant interactions, and if these stressors should be grouped (e.g., resource and non-resource, abiotic and biotic, etc.) to enhance predictability. From a series of studies conducted herein, I concluded that co-occurring stressors are important factors that control complex species interactions as shown in my MSGH modeling approach. Further, future theories need to incorporate species-specific and stressor specific grouping when modeling how species interactions shape communities. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2013.

Mangrove forests are an integral part of coastal wetlands in temperate and tropical regions of the world, including New Zealand. These coastal plants act as a shelter,feeding and breeding grounds for marine and terrestrial organisms. Many overseas studies have investigated the importance of mangrove and seagrass habitats in sustaining coastal food chains. In New Zealand, however, only a few studies have addressed the ecology and food web dynamics of these temperate ecosystems.As a first step to investigate the nutrient dynamics of estuarine food webs in temperate estuaries, this study aimed to quantify the nutrient concentrations in the catchment and the estuary of Matapouri, northern New Zealand. Field studies involved the collection of surface fresh and estuarine water (during low and high tides). Plant material (mangrove and seagrass), and sediment samples were collected at various sites within the estuary. Chemical analyses were carried out to determine the concentration of C, N, P and Si macronutrients and Fe and Zn micronutrients during different seasonal rainfall events.The results suggest that mangrove habitats may act as a source of POC, but not DOC for the adjacent aquatic habitats (i.e., seagrass, sand flats, channels), while seasgrass beds contribute more N to the estuarine system than the mangrove forests. The concentrations of N and P nutrients are strongly influenced by both the freshwater inputs and the bio-chemical processes within the estuary. The results obtained point to the freshwater streams as the main source of Si and Fe in the estuary. However, Zn was higher in the estuarine water compared to the catchment freshwater. NO3 -, NH4 +, Fe and Zn concentrations showed strong responses to the higher rainfall months reaching their highest level during the winter and early spring seasons. Conversely, P concentrations showed a negative seasonal pattern, which was linked to monthly rainfall events.Mangrove sediments may operate as a sink for the heavy metal Zn in Matapouri estuary. Iron concentration in seagrass leaves exceeded that in mangrove leaves by 65 orders of magnitude. The study suggests that seagrass plants could be used as a biological indicator of iron concentration in the estuary. The complex dynamics of bio-chemical cycles in Matapouri indicate that each habitat within the estuary has specific nutrient contributions to the estuarine food web system. However, the catchment and oceanic influences must also be considered in the nutrient balance of these coastal environments.

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 69-76). / x, 76 leaves, bound ill. (some col.), col. map 29 cm

Thesis (M. Sc.)--University of Adelaide, 1987. / Folded map in pocket. Includes bibliographical references (leaves 136-143).