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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Towards a new approach for coastal governance with an assessment of the Plettenberg Bay nearshore linefisheries

Smith, Martin Kyle Stratford January 2006 (has links)
Under the guidance of the new coastal management policies within South Africa this thesis advocates a more integrated, co-operative approach to local coastal management. The project aimed to acquire baseline information on the local nearshore fishery and resource state and to propose a set of indicators that could be incorporated into the new management strategy. To gather the required information the project was split into two parts: 1) An assessment of the local linefisheries and 2) A comparative study of the reef fish community structure between exploited and unexploited reefs. The local linefisheries were assessed through the use of launch records, commercial catch records, access point and boat based surveys. A questionnaire was used to gather data on catch and effort, fisher demographics, fisher attitudes towards and knowledge of the current management regulations, assess the efficacy of the fisheries inspectorate and highlight spatial areas of fishing pressure. A total of 252 interviews and catch inspections were conducted. Total effort for the ski-boat fishery estimated from the access point survey was 890 boat days.year⁻¹ or 3560 fisher days. year⁻¹ compared to 736 boat days.year⁻¹ or 2944 fisher days. year⁻¹ recorded in the launch records. Effort was seasonal with greater pressure occurring over the summer holiday period. Analysis of the catch showed that Merluccius capensis, Argyrozona argyrozona, Argyrosomus inodorus, Chrysoblephus laticeps and Atractoscion aequidens were the most frequently caught species. The overall CPUE was 3.00±5.54kg.fisher⁻¹.day⁻¹ or 4.71±4.117 fish.fisher⁻¹.day⁻¹. Estimated targeted CPUE was 0.91±0.67kg.fisher⁻¹.day⁻¹ or 0.97±0.77 fish.fisher⁻¹.day⁻¹ for C. laticeps, 8.47±8.57kg.fisher⁻¹.day⁻¹ or 1.24±1.16 fish.fisher⁻¹.day⁻¹ for A. aequidens and 2.05±3.78kg.fisher⁻¹.day⁻¹ or 1.10±1.80 fish.fisher⁻¹.day⁻¹ for A. inodorus. Issues identified included poor fisher knowledge regarding linefish regulations, the low occurrence of fishery inspections and a limited degree of noncompliance. Although most fishers supported the current linefish management regulations, when tested on the size limits, bag limits and closed seasons of their target species a high proportion of fishers did not know the regulations (recreational 64%, charter 53%, commercial 42%). Furthermore only 27% of fishers had had their catch inspected whilst fishing in Plettenberg Bay and the majority of these had only been inspected once. Just over half the interviewees (60%) indicated that fishing had deteriorated within Plettenberg Bay with fewer and smaller fish being caught. The most common causes cited for this decline were commercial and recreational overfishing respectively. Underwater point counts and experimental angling were used to rapidly assess the state of the reef fish resource in Plettenberg Bay through a comparative study of the community structure between two exploited sites in Plettenberg Bay and two protected sites within the Tsitsikamma National Park. Generalized linear modeling showed that relative density of certain species was significantly different between the protected reefs inside the TNP and those exploited reefs within Plettenberg Bay. Both P. rupestris and C. laticeps had greater densities within the protected area whilst Chisquared tests showed that the size frequency distributions were significantly different with larger size-classes and the maximum size of fish greater within the reserve. These trends were noted with both the underwater visual surveys and the experimental angling. Multi-dimensional scaling and cluster analysis showed that there was an overall difference in the community structure between the study sites. It is hypothesised that through removal of key reef species and larger individuals that fishing has directly and indirectly affected the overall community structure. Within a simple framework based on ecological, institutional and social sustainability domains along with the results of the study area, a set of indicators is proposed and the sustainability of the local fishery scored within a rapid assessment matrix. The socio-economic domain scored the highest (83%) whilst the institutional domain scored the lowest (8.3%) and the ecological domain scored 25%, giving a total sustainability score of 38.8%. The results of this matrix show that at present the local fishery is non-sustainable and in need of greater management. By synthesizing papers dealing with and based on the concepts involved in Integrated Coastal Management, a structured approach is proposed to developing and implementing more holistic local coastal governance. It is envisaged that the framework to implement such an approach should be through the development of a local Coastal Management Plan and a subsidiary Bay Management Plan. Although stakeholder participation and representation is an essential component in the development of these plans, it is recommended that the local municipality should be the lead agent and incorporate the plans into the local Integrated Development and Spatial Plans thereby gaining long term local government support.
282

The geographic stock structure of chokka squid, Loligo Reynaudi, and its implications for management of the fishery

Van der Vyver, Johan Samuel Frederik January 2014 (has links)
It is currently hypothesised that the chokka squid (Loligo reynaudi) consist of a single stock. This was tested through a spatial comparison of the morphology of this species. Forty three morphometric characters were measured from 1079 chokka squid collected from three regions: the south coast of South Africa, the west coast of South Africa, and southern Angola. While no significant differences were found for the hard body parts, results from discriminant function analyses showed the soft body morphometric characters from each of the three regions differed, with an overall correct classification rate of 100% for males and 99% for females in all three regions. Due to the existing model being used to assess the resource currently being updated it was not feasible to apply this model to the area-disaggregated data from this study. Rather, the CPUE trends and catches from the area-disaggregated data were compared against those of the area-aggregated data, as a first attempt to discern any appreciable differences which would suggest the use of disaggregated data in future assessments. Both the trawl and jig CPUE trends from the area-disaggregated analysis differed only slightly from those of the area-aggregated data. Similarly, the spring and autumn biomass trends for the main spawning area (east of 22°E) followed the same trends as for the full area. It is therefore concluded that there is currently no need to assess the resource on an area-disaggregated basis.
283

Movement patterns, stock delineation and conservation of an overexploited fishery species, Lithognathus Lithognathus (Pisces: Sparidae)

Bennett, Rhett Hamilton January 2012 (has links)
White steenbras Lithognathus lithognathus (Pisces: Sparidae) has been a major target species of numerous fisheries in South Africa, since the late 19th century. Historically, it contributed substantially to annual catches in commercial net fisheries, and became dominant in recreational shore catches in the latter half of the 20th century. However, overexploitation in both sectors resulted in severe declines in abundance. The ultimate collapse of the stock by the end of the last century, and the failure of traditional management measures to protect the species indicate that a new management approach for this species is necessary. The species was identified as a priority for research, management and conservation in a National Linefish Status Report. Despite knowledge on aspects of its biology and life history, little is known about juvenile habitat use patterns, home range dynamics and movement behaviour in estuaries. Similarly, the movement and migration of larger juveniles and adults in the marine environment are poorly understood. Furthermore, there is a complete lack of information on its genetic stock structure. Such information is essential for effective management of a fishery species. This thesis aimed to address the gaps in the understanding of white steenbras movement patterns and genetic stock structure, and provide an assessment of its current conservation status. The study adopted a multidisciplinary approach, incorporating a range of methods and drawing on available information, including published literature, unpublished reports and data from long-term monitoring programmes. Acoustic telemetry, conducted in a range of estuaries, showed high site fidelity, restricted area use, small home ranges relative to the size of the estuary, and a high level of residency within estuaries at the early juvenile life stage. Behaviour within estuaries was dominated by station-keeping, superimposed by a strong diel behaviour, presumably based on feeding and/or predator avoidance, with individuals entering the shallow littoral zone at night to feed, and seeking refuge in the deeper channel areas during the daytime. Conventional dart tagging and recapture data from four ongoing, long-term coastal fish tagging projects, spread throughout the distribution of this species, indicated high levels of residency in the surf zone at the late juvenile and sub-adult life stages. Consequently, juvenile and sub-adult white steenbras are vulnerable to localised depletion, although they can be effectively protected by suitably positioned estuarine protected areas (EPAs) and marine protected areas (MPAs), respectively. It has been hypothesized that adult white steenbras undertake large-scale coastal migrations between summer aggregation areas and winter spawning grounds. The scale of observed coastal movements was correlated with fish size (and age), with larger fish undertaking considerably longer-distance coastal movements than smaller individuals, supporting this hypothesis. Given the migratory behaviour of adults, and indications that limited spawning habitat exists, MPAs designed to protect white steenbras during the adult life stage should encompass all known spawning aggregation sites. The fishery is plagued by problems such as low compliance and low enforcement capacity, and alternative management measures, such as seasonal closure, need to be evaluated. Despite considerable conventional dart tagging effort around the coastline (5 782 fish tagged) with 292 recaptures there remains a lack of empirical evidence of fish migrating long distances (> 600 km) between aggregation and spawning areas. This uncertainty in the level of connectivity among coastal regions was addressed using mitochondrial DNA sequencing and genotyping of microsatellite repeat loci in the nuclear genome, which showed no evidence of major geographic barriers to gene flow in this species. Samples collected throughout the white steenbras core distribution showed high genetic diversity, low genetic differentiation and no evidence of isolation by distance or localised spawning. Although historically dominant in several fisheries, analysis of long-term commercial and recreational catch data for white steenbras indicated considerable declines and ultimately stock collapse. Improved catch-per-unit-effort in two large MPAs subsequent to closure confirmed that MPAs can be effective for the protection of white steenbras. However, the current MPA network encompasses a low proportion of sandy shoreline, for which white steenbras exhibits an affinity. Many MPAs do not prohibit recreational shore angling, which currently accounts for the greatest proportion of the total annual catch. Furthermore, EPAs within the juvenile distribution protect a negligible proportion of the total available surface area of estuaries – habitat on which white steenbras is wholly dependent. Despite some evidence of recent increases in abundance in estuaries and the surf zone in certain areas, white steenbras meets the criteria for “Endangered” on the IUCN Red List of Threatened Species, and for “Protected species” status on the National Environmental Management: Biodiversity Act of South Africa. The species requires improved management, with consideration for its life-history style, estuarine dependency, surf zone residency, predictable spawning migrations and its poor conservation status. The multidisciplinary approach provides valuable information towards an improved scientific basis for the management of white steenbras and a framework for research that can be adopted for other overexploited, estuarine-associated coastal fishery species.
284

Social capital and fisheries co-management in South Africa: the East Coast Rock Lobster Fishery in Tshani Mankozi, Wild Coast, Eastern Cape

Kaminsky, Alexander January 2012 (has links)
It is evident that natural fish stocks are in rapid decline and that millions of people around the world rely on these resources for food and for securing a livelihood. This has brought many social scientists, biologists and fisheries experts to acknowledge that communities need to take more control in managing their natural resources. The paradigm shift in fisheries management from a top-down resource orientated control to a participatory people-centred control is now being advocated in many maritime nations in facilitating community-based natural resource management. At the heart of these projects is the establishment of institutions and social networks that allow for clear communication and information sharing, based on scientific data and traditional knowledge which ultimately allow empowered communities to collectively manage their resources in partnership with government, market actors and many other stakeholders. Central to the problem is the issue of access rights. In many situations where co-management of natural resources through community-government partnerships is advocated, the failure of coastal states to provide adequate legislature and regulatory frameworks has jeopardised such projects. A second issue is the failure of many states to provide adequate investments in social and human capital which will enable communities to become the primary stakeholder in the co-management of their natural resources. Whilst investments like capacity building, education, skills training and development, communications and institution building can initially require high financial investments, the regulatory costs for monitoring, controlling and surveying fish stocks along the coastline will go down as communities take ownership of their resources under sustainable awareness. The main unit of investment therefore is social capital which allows for the increase in trust, cooperativeness, assertiveness, collective action and general capabilities of natural resource governance. High levels of social capital require good social relations and interactions which ultimately create a social network of fishers, community members and leaders, government officials, market players, researchers and various other stakeholders. Co-management thus has an inherent network structure made up of social relations on a horizontal scale amongst community members as well as on a vertical scale with government and fisheries authorities. These bonding relations between people and the bridging relations with institutions provide the social capital currency that allows for a successful co-management solution to community-based natural resource governance. The South African coastline is home to thousands of people who harvest the marine resources for food security and securing a basic income. Fishing is a major cultural and historical component of the livelihoods of many people along the coastline, particularly along the Wild Coast of South Africa located on its South-eastern shoreline. Due to the geopolitical nature of South Africa’s apartheid past many people were located in former tribal lands called Bantustans. The Transkei, one of the biggest homelands, is home to some of South Africa’s poorest people, many of whom rely on the marine resources. By 1998 the government sought to acknowledge the previously unrecognised subsistence sector that lived along the South African coastline with the promulgation of the Marine Living Resources Act. The act sought to legalise access rights for fishers and provide opportunities for the development of commercial fisheries. The act and many subsequent policies largely called for co-management as a solution to the management of the subsistence sector. This thesis largely explains the administrative and legislative difficulties in transporting the participatory components of co-management to the ground level. As such co-management has largely remained in rhetoric whilst the government provides a contradictory policy regarding the management of subsistence and small-scale fishers. This thesis attempts to provide qualitative ethnographic research of the East Coast Rock Lobster fishery located in a small fishing village in the Transkei. The fishery falls somewhere on the spectrum between the small-scale and subsistence sector as there are a basket of high and low value resources being harvested. It will be argued that in order to economically and socially develop the fishery the social capital and social networks of the community and various stakeholders needs to be analysed in order to effectively create a co-management network that can create a successful collective management of natural resources thereby sustaining these communities in the future.
285

Mobilising processes of abstraction, experiential learning and representation of traditional ecological knowledge in participatory monitoring of mangroves and fisheries : an approach towards enhancing social learning processes on the eastern coast of Tanzania

Sabai, Daniel January 2014 (has links)
This study addresses a core problem that was uncovered in records from coastal management monitoring initiatives on the eastern coast of Tanzania associated with the application and use of coastal monitoring indicators developed by external development partners for the coastal zone. These records suggest that local communities, who are key actors in participatory monitoring of coastal and marine resources, face many challenges associated with adapting and applying the said frameworks of indicators and monitoring plans. These indicators tend to be scientifically abstracted and methodologically reified; given prevailing contextual and socio‐cultural realities amongst them. The research project addresses the following key research question: How can processes of abstraction, conceptualisation, and representation of TEK contribute to the development of coastal management indicators that are less reified, more contextually and culturally congruent, and which may potentially be used by resource users in the wider social learning process of detecting trends, threats, changes and conditions of mangrove and fisheries resources? In response to the contextual problem and the research question, the study employs processes of abstraction and experiential learning techniques to unlock knowledge that local communities have, as an input for underlabouring existing scientific indicators on the Eastern coast of Tanzania. The research is constituted as critical realist case study research, involving two communities on the eastern coast of Tanzania, namely the Moa and the Boma communities (in Mkinga coastal district). Overall, the study involved 37 participants in a series of interviews, focus group discussions, and experiential learning processes using visualised data, and an experiential learning intervention workshop, and follow‐ups over a period of 3 years. The study worked with mangroves and fisheries to provide focus to the case study research and to allow for in‐depth engagement with the assumptions and processes associated with indicators development and use. Through the above mentioned data generation processes, critical realist analysis, and experiential learning processes involving abstraction and representation of traditional ecological knowledge held by mangrove restorers and fishers in the study areas, the study uncovers possible challenges of adapting and applying scientific indicators in participatory monitoring of a mangrove ecosystem. Using ampliative modes of inference for data analysis (induction, abduction and retroduction) and a critical realist scientific explanatory framework known as DRRREI(C) (Resolution, Re‐description, Retrodiction, Elimination, Identification, & Correction) the study suggests a new approach that may lead to the development of a framework of indicators that are less reified, more congruent to users (coastal communities), and likely to attract a wider context‐based social learning which favours epistemological access between scientific institutions (universities inclusive), and local communities. It attempts to establish an interface between knowledge that scientific institutions produce and the potential knowledge that exists in local contexts (traditional ecological knowledge), and seeks to widen and improve knowledge sharing and experiential learning practices that may potentially benefit coastal and marine resources in the study area. As mentioned above, the knowledge and abstraction processes related to the indicators development focussed on the mangrove ecosystem and associated fisheries, as engaged in the two participating communities in the eastern coast of Tanzania. The specific findings are therefore limited by the case boundaries, but the methodological process could be replicated and used elsewhere. The study’s contributions are theoretical and methodological, but also social and practice‐centred. The study brings into view the need to consider the contextual relevance of adapted knowledge, the capacity or ability of beneficiaries to adapt and apply scientific models, frameworks or tools, and the potential of local knowledge as an input for enhancing or improving monitoring of mangroves and mangrove‐based fisheries. Finally, the study comes up with a framework of indicators which is regarded by the coastal communities involved in the study as being less reified, more contextually and culturally congruent, and which may potentially be used in detecting environmental trends, threats, changes and conditions of mangrove and fisheries resources, and attract wider social learning processes.
286

A method for imputing economic value to ecological goods and services provided by the Knysna River

Saunders, James Woodward January 2008 (has links)
The purpose of this thesis was to develop a method by which economic value can be imputed from an economic activity to a non-market ecological function or service which contributes to that economic activity. The Knysna River in South Africa was chosen as the ecological function which supported three economic activities from which value was to be imputed; these were the Knysna Municipal Water Supply, Fish Production in the Knysna Estuary and Production of Indigenous Forest within the Knysna Catchment. Three underlying assumptions and two functional operations were required in order to implement the suggested method. The underlying assumptions were: - The ecological and economic activities considered are within a single catchment. - The allocation of value imputed for a specific economic activity to the ecological function or service under consideration (in this case the Knysna River) is proportional to the total contribution of ecological functions or services contributed to the economic activity. - The valuation of the economic activity for the purposes of obtaining a price-quantity point on a demand function is to be full cost pricing with no producer surplus. The two functional requirements were: - Diagram or map the linkages between an economic activity and the supporting ecological functions. - Determine the consumer surplus related to an incremental change in quantity under a demand function where the original price and quantity are known. A value from each of the economic activities was imputed to the Knysna River. However, the method was not tested. Nonetheless applying the equations and collecting the required data allowed several methodological needs to be clearly pointed out. The most acute deficiency was difficulty in obtaining secondary data from governmental agencies, commercial representatives and existing published academic research to ensure a robust price. Also, scientific information was not sufficiently available for allocating ecological contributions to the economic activities. Even with the shortage of credible data the method appears to allow non-market ecological functions to be valued in context of an existing economic system.
287

Tuna management and UNCLOS : implementation of UNCLOS through the Forum Fisheries Agency

Aqorau, Transform January 1990 (has links)
Regional organisations have often played a catalytical role in developing regional ocean regimes that directly pertain to the peculiar needs and circumstances of a given region. As a response to the challenges imposed by the United Nations Convention on the Law of the Sea, the island States of the South Pacific region established the South Pacific Forum Fisheries Agency, with the specific mandate to assist them manage the enormous tuna resource of the region. The thesis seeks to ascertain the extent to which those needs have been satisfied. The thesis begins with the hypothesis that the Forum Fisheries Agency has in fact fulfilled those needs. The analysis is based on inferences which are drawn from the functions and responsibilities of the Forum Fisheries Agency, and certain significant legal developments it has helped spawn. The thesis does not engage in a cost/benefit evaluation of the Forum Fisheries Agency because that is an issue best left to the purview of individual member States to determine. Two conclusions are drawn from the analysis. First, the Forum Fisheries Agency has met the needs of the island States. Secondly, through the Forum Fisheries Agency, the island States are implementing the United Nations Convention on the Law of the Sea. / Law, Peter A. Allard School of / Graduate
288

An ecological investigation of the Doorndraai Dam, Sterk River, Transvaal, with special reference to fish management

Batchelor, Garth Rohan 03 March 2014 (has links)
M.Sc. (Zoology) / Please refer to full text to view abstract
289

Developing and Calibrating the Hydrodynamic and Water Quality Model CE-QUAL-W2 for Banks Lake Washington

McCulloch, Andrew John 01 January 2011 (has links)
Located in central Washington State, Banks Lake serves as an irrigation storage reservoir for the Columbia Basin Irrigation Project and is home to a diverse fisheries population. The current hydrologic management strategies used for Banks Lake have been chosen to serve two purposes: to adequately store and provide irrigation water for the Columbia Basin Irrigation Project and to maintain a healthy aquatic environment suitable for the growth and habitation of local flora and fauna. Increased needs for irrigation water within arid central Washington poses additional challenges to reservoir managers so that irrigation needs are met without damaging the present aquatic environment within Banks Lake. Future plans by the Washington Department of Ecology to use Banks Lake storage to replenish ground water reserves of the Odessa Subarea aquifer have required an investigation into how increased seasonal drawdown may affect fish growth, fish habitat and overall limnology of Banks Lake. The goal of this project is to produce a hydrodynamic and water quality model of Banks Lake that can predict the impacts of management strategies on the lake's water quality and the linkage of lake management to fish habitat.
290

Evolution of property rights to a natural resource: the oyster grounds of the Chesapeake Bay

Santopietro, George D. January 1986 (has links)
Economists take an interest in property rights structures because of their importance in the definition of incentive structures. Fisheries have been analyzed as open access resources because they are not often organized around private property rights. The lack of private property rights though should not be taken to imply unlimited access. There is a need to differentiate between situations in which an institutional structure supports a system of common property rights from those in which access to a resources is truly limited. In this study, a conceptual framework of the structure and workings of property rights to natural resources is developed. This includes a taxonomy of possible property rights structures that differentiates among types and degrees of common and private property. The study then compares and contrasts the differing views in the economics literature on the process by which property rights evolve. This conceptual framework is used to develop a set of research questions that will structure the inquiry about the evolution of property rights to a specific natural resource, the Chesapeake Bay oyster grounds. The conventional and Institutionalist perspectives are related to fishery management policy and their differences assessed. The Institutionalist perspective is shown to raise questions about the historical development of property rights that would not be considered by conventional economists. The resulting research questions are used to explain the economic history of the property rights to the Chesapeake Bay oyster grounds from 1607 to 1986. In Maryland and Virginia certain grounds of the Chesapeake Bay are reserved as a public oyster fishery, but, they have been regulated and managed by the states. In the history of the fishery, those who harvest from the public grounds have continually resisted the extension, or even encouragement of oyster cultivation on private leaseholds. The primary advocates of greater privatization of the bottoms have been economists and biologists. The governments of each state have chosen to maintain the commons in order to provide employment for watermen and to more widely distribute income among them. The results of a survey of Virginia's oyster harvesters are presented. These provide further insights for discussing the role of the watermen in the evolution of property rights, and help to form conclusions on the future of the fishery. This case study leads to the discussion of conclusions on the theory of the economics of property rights. / Ph. D.

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