Ecosystem modelling allows for an understanding of the structure and functioning of ecosystems. During this study, the oligotrophic KwaZulu-Natal (KZN) Bight, a data-limited system on the east coast of South Africa, was modelled. A framework for modelling data-poor systems, incorporating the construction of multiple models, sensitivity analyses and comparative analyses was applied to the Bight using literature data. Models converged on general trends of ecosystem functioning showing 99% of flows originated from detritus, primarily imported from rivers. The largest source of riverine detritus is the Thukela River which flows into the central Bight. This area supports a shallow-water prawn trawl fishery which targets penaeid prawns. Fisheries time series‘ were incorporated into the model framework to study the effects of prawn trawling and the decrease in prawn recruitment, caused by estuarine nursery loss, on the central Bight ecosystem. Dynamic simulations suggest the biomass of biotic groups were more affected by prawn recruitment level than trawling effort level. To understand the importance of nutrients in more detail, nutrient content, biomass and stoichiometric ratios were documented for various pelagic and demersal functional groups, and compared between areas in this oligotrophic system. Results showed the central Bight had the highest carbon, nitrogen and phosphorus biomasses, due to riverine nutrient sources, and the southern Bight had the lowest. In addition, the demersal community had higher biomasses than the pelagic community for all nutrients. Nutrient dynamics and limitations within the Bight were explored through the construction and analysis of trophic flow networks of carbon, nitrogen and phosphorus for the southern, central and northern Bight. Network analyses suggest nutrient cycling was lowest in the central Bight, and highest in the southern Bight. Cycling of nitrogen was highest in all areas due to the dominance of benthos, in terms of biomass, which was nitrogen-limited. Higher trophic levels were found to be phosphorus-limited. However many pelagic groups were co-limited by nitrogen and phosphorus, probably due to the oligotrophic nature of the bight. This suite of ecosystem models provides the first holistic view of the KZN Bight and an understanding of ecosystem functioning in the southern, central and northern Bight. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2012.

The KwaZulu‒Natal Bight is formed from a narrow indentation in the SE coast of South Africa with the waters within considered to be oligotrophic. These waters therefore depend on both allochthonous sources of nutrients such as intermittent upwelling of deeper water and nutrients supplied by riverine inputs, as well as the autochthonous nutrients supplied by phytoplankton production, microbial fixation and recycling of nutrients by the microbial loop. Two African Coelacanth Ecosystem Programme cruises were undertaken during 2010, during the wet summer, and dry winter months. During each cruise, the waters of the KZN‒B were sampled rapidly to provide spatial scales (synoptic) of bacterial abundance and biomass, as well as at four predetermined locations to determine temporal scales (focus) of bacterial abundance, biomass and productivity. During the synoptic section, samples were taken in surface waters, close to F‒max (the depth at which phytoplankton were at their most dense as determined by in situ fluorometry), below the F‒max (where depths exceeded 50 m), and near the bottom. These samples were fixed with formaldehyde, stained with DAPI and cells were visualised by epifluorescent microscopy. During the focus section, samples were taken in surface waters, close to F‒max and below F‒max and incubated with 3H‒Thymidine to determine bacterial productivity. Bacterioplankton dynamics (numbers, biomass and productivity) for both cruises, synoptic section, were higher within the photic zone and near riverine influenced waters, with summer showing higher dynamics than winter. Irrespective of season, bacterioplankton dynamics decreased with increasing distance from the coast as well as with increasing depth, potentially via bottom‒up control mechanisms. Results obtained from the focus section of both cruises showed a significant difference between seasons for the Thukela Mouth and Richards Bay North, while no difference at the Durban Eddy. These results from the focus section suggest that bacterioplankton temporal dynamics were more top‒down controlled, rather than environmentally influenced, resulting in fluctuating dynamics over time. Overall, it is proposed that the degree of inorganic nutrient supply to the phytoplankton, resulted in the formation of DOM for use by the heterotrophic bacteria, resulting in a bottom‒up control mechanism, where Chl‒a concentrations within the euphotic zone induces either top‒down or bottom‒up control mechanisms on the heterotrophic bacteria directly affecting their numbers, biomass and productivity. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2013.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 84-94).

The study examined the past and present spatial distribution of the Florida tree snail, L. fasciatus solidus, in the Long Pine Key area of the Everglades National Park. Remote sensing and mobile GIS were used to create a GIS database of the field research results. Collection and survey-based data were used to create a current spatial distribution map of L. fasciatus solidus throughout the Long Pine Key area. The data collected during the 2006 survey were compared to a 1931 survey of the same study area conducted by Dr. William Clench of the Museum of Comparative Zoology (MCZ) of Harvard University. The data was used to determine the success of L. fasciatus solidus from 1931 to 2006, to evaluate a correlation between hammock size and the number of color forms, and to detect migration patterns of L. fasciatus solidus within the Long Pine Key area of Everglades National Park. Based on the average success rate for the seven color forms and the hammocks, the L. fasciatus solidus population in the Long Pine Key area exemplifies one of a stable community. Each color form used for the analysis had a success rate between 67% and 100%. These percentages can only be the worst case scenario based on the fact that many Liguus were not observed, and any others that would have been observed, would only increase the success rate. / by Jason R. Fadely. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

In estuaries, like the Indian River Lagoon, mesozooplankton have a vital role in the food web by connecting trophic levels. In this study, mesozooplankton abundance and species composition were monitored weekly on the incoming and outgoing tides from September 2006 to May 2009. For the incoming tide, the mean abundance was 2298.2 mesozooplankton/m3 (+/-325.2), and for the outgoing tide the mean abundance was 1180.0 mesozooplankton/m3 (+/-153.1). The mesozooplankton abundance on the incoming tide was significantly greater than on the outgoing tide. The most abundant type of mesozooplankton was the copepod Acartia tonsa, representing 35.0% and 52.1% of the individuals on the incoming and outgoing tides respectively. Mesozooplankton abundance values were compared with environmental data obtained from the South Florida Water Management District. The strongest positive correlation was found between chlorophyll a concentrations and A. tonsa abundance, likely due to phytoplankton being the primary food source for A. tonsa. / by Miranda Hoover Kerr. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 107-117). Also available on the World Wide Web.

Thesis (PhD (Botany and Zoology))—University of Stellenbosch, 2009. / Natural ecosystems provide many services that are crucial for sustainability and health of human society. Ecosystem services are the benefits people obtain from ecosystems (i.e. goods and services) and can be classified into provisioning (e.g. fibre, fuel wood); regulating (e.g. water and climate regulation); supporting (e.g. soil retention) and cultural (e.g. aesthetic value). The growing global human population and other threats place enormous stress on the natural environment reducing its capability to provide services. According to the Millennium Ecosystem Assessment, more than 60% of ecosystem services worldwide are being degraded or used unsustainably. The need to safeguard ecosystem services is therefore urgent. Biodiversity underpins most ecosystem services, but the functional relationship between biodiversity and services is not well known. A wide range of strategies exist for safeguarding biodiversity, but no such approaches have been developed for ecosystem services. A key conservation strategy is the use of systematic conservation planning to identify priority areas where effort should be focused. There are calls for the inclusion of ecosystem services into conservation planning geared towards biodiversity. Ecosystem services have been used for many years as an additional rationale to justify biodiversity conservation and it is often assumed that conserving biodiversity will also conserve services. However, it is unclear how different facets of biodiversity relate to different services and to what extent conserving biodiversity will safeguard services. This thesis addresses a range of issues relating to the integration of ecosystem services into conservation planning in South Africa. I first investigated the status of ecosystem services in conservation planning worldwide by reviewing the conservation planning literature from 1998 to 2005. Ecosystem services are clearly not adequately addressed in conservation assessments. A critical barrier preventing the inclusion of ecosystem services in conservation plans is the lack of spatially-explicit data. I developed a methodology for mapping ecosystem services in South Africa and mapped the distribution of five important ecosystem services (surface water supply, water flow regulation, carbon storage, soil retention and accumulation). Using the five services to examine relationships within services and between biodiversity revealed a lack of congruence between services and different levels of congruence with biodiversity features. However, including ecosystem services in a biodiversity assessment captured at least thirty percent of each of three services selected for the study. Nevertheless, a biodiversity plan may not necessarily capture adequate amounts of ecosystem services. Ecosystem services should be planned for explicitly instead of relying on biodiversity data. I identified priorities that met targets for five services in the grasslands of South Africa. This thesis provides new insights on planning for biodiversity and ecosystem services. The results have immediate applicability for conservation planning in South Africa. Keywords: Conservation planning, conservation assessments, ecosystem functions, ecosystem processes, ecosystem services, natural capital, biodiversity, soil, water, carbon.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

This is an applied ethnographic study of Southern Paiute cultural resources and how these are related to the natural ecosystems that surround and incorporate Zion National Park in southern Utah and Pipe Spring National Monument in northern Arizona. Southern Paiute people perceive Zion National Park and Pipe Spring National Monument as places whose significance derives from larger cultural and ecological landscapes. Southern Paiute people view both parks as being parts of riverine ecosystems. Zion National Park is a place along the Virgin River, and Pipe Spring National Monument part of the greater Kanab Creek Hydrological System. The current boundaries of both parks are largely irrelevant for understanding the lives of birds that fly along the river, of deer who seasonally migrate up and down the river, and of fish who swim in the river. Paiute people, whose ancestors lived along these riverine ecosystems for a thousand years or more, recognize that the plants they gathered, the animals they hunted, and the lives they lived are unrelated to the current boundaries of these two parks. As a result, the National Park Service and the Southern Paiutes arrived at the same conclusion: that is, to understand the cultural and natural significance of these parks requires knowledge of their relationships with other places. Thus it is both administratively and culturally appropriate for this applied ethnographic study to follow an ecosystem approach. This study was unique in two major ways. Unlike many other American Indian cultural resources studies conducted within National Parks at this period of time, this study moved beyond the formal boundaries of these NPS units in an effort to understand them as components of a broader natural ecosystem. As such, this study built upon the scientific and social framework for ecologically based stewardship of Federal lands and waters. This report provides both the ethnographic information relating to Pipe Spring National Monument and Zion National Park. This information was then incorporated in the parks’ resource management plans

Previous pulse-chase experiments have revealed a wide diversity of benthic response patterns to organic matter (OM) input depending on environmental setting, benthic community structure and experimental conditions i.e. quantity and quality of the added OM.  However, the mechanisms and interaction of environmental and biological factors that produce an observed response pattern are poorly understood. The present thesis set out to improve our current understanding on the set of parameters that determine benthic response patterns.  The core of this study was based on two pulse-chase experiments in two bathyal settings: the Faroe-Shetland Channel (FSC) and the SW Cretan slope in the E. Mediterranean (E. Med).  The sub-zero temperatures in the FSC enabled the observation of the benthic response in “slow-motion” and showed that the response is not static but instead might go through various “phases”.  In the warm E. Med, C processing rates were considerably lower compared to previous measurements in adjacent regions.  The discrepancy was attributed to the particularly refractory sedimentary OM at the sampling station with apparent consequences for the physiological state of the bacterial community.  Both experiments showed that bacterial metabolism and its regulation is a key factor determining the reaction of the benthic community to OM inputs.  This thesis provided further understanding on the short-term fate of organic C in deep-sea sediments but also raised certain issues that could be addressed in future studies.