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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.
31

Measuring the Potential to Adopt Self Governance for the Management of a Common Pool Resource

Colin Castillo, Sergio 2011 December 1900 (has links)
Self governance has proved to be a suitable instrument for the management of a common pool resource like fisheries. Under self governance, individuals organize themselves for the use of a resource, to deal with problems derived from the free access: overexploitation and low profit levels. Although there is a large amount of research devoted to investigate the common pool resources and self governance, there are two areas that represent a gap in the current research. One, what are the main variables related to likely self governance adoption? Two, how is the potential for self governance related to the economic efficiency of the resource users? Unlike most of previous research that involves ex-post analysis, this is an ex-ante assessment of the potential for self governance for management of a common pool resource: a small-scale fishery located in Mexico. This research hypothesizes a positive relationship between fisher's technical efficiency and the likely adoption of self governance for the management of the fishery. Taking a set of theoretical conditions, this research assesses the fishers' perception on the adoption of self governance. Further, a stochastic frontier analysis is applied to estimate the technical efficiency of each fisher. Finally, a relationship between the potential for self governance with technical efficiency, revenue, and other variables such as education and fisher experience is explored. The results show no significant effect of technical efficiency and revenue on the potential for self governance, as well a weak positive effect of fisher experience on the likelihood for self governance adoption. The findings of this research may be useful to improve the efficiency of the fishing activity and encourage the adoption of self governance in the study site. The method proposed in this research is based on attitudes of the fishers, and it represents a step toward understanding apriori whether self governance would be implementable or not. Thus, as an ex-ante assessment, it is hoped to help predicting individual's behavior to deal with the overexploitation and low income levels derived from the use of a common pool resource.
32

Reducing Uncertainty in Fisheries Management: The Time for Fishers' Ecological Knowledge

Carr, Liam 2012 May 1900 (has links)
This dissertation work presents a novel method for addressing system uncertainty to improve management of a small-scale fishery in St. Croix, United States Virgin Islands. Using fishers' ecological knowledge (FEK), this research examines existing perspectives and biases through the Q-Method to identify regulatory inefficiencies in the management framework and strengthen the rationale for including fishers into the management process, develops a coupled behavior-economics model to predict the likelihood of fishing the preferred grounds under a range of physical and regulatory conditions, establishes a baseline assessment of a spawning aggregation of mutton snapper following sixteen years of protection through a no-take marine protected area, and conducts a discrete choice method test to examine likely public support for FEK-based proposed regulatory alternatives. This work contributes to an under-studied and much-needed area of fisheries management, that of incorporating socioeconomic motivations within an ecosystem-based framework. As fisheries management efforts begin to embrace ecosystem-based approaches, the need for understanding and incorporating the knowledge and behavior of fishers into management has never been greater. Ecological goals of fishery sustainability and continued habitat function cannot be achieved without first understanding how fishers view and respond to any regulatory environment and then developing a framework that achieves the greatest support for those regulations. The time has come for incorporating FEK into ecosystem-based fisheries management.
33

A tale of two committees : evaluating collaborative management planning in Canada's Pacific groundfish fisheries

Davis, Neil 05 1900 (has links)
Governing agencies increasingly employ collaborative forms of decision-making in fisheries management to improve decision quality and legitimacy. However, crafting fair and effective collaborative processes which will achieve these benefits is often difficult. In an effort to identify keys and obstacles to success, this research evaluated the Commercial Groundfish Initiative, a collaborative planning process tasked with reforming the management of Canada's Pacific groundfish fisheries. Using semi-structured interviews, I gathered the perspectives of participants from the two committees within the process: a consensus-based committee of commercial representatives and a committee broadly representative of other interest groups for which consensus was encouraged but not mandated. Control over the design of a proposal for management reform was asymmetrically divided between the two committees, giving the commercial committee the primary role. Participants from the commercial committee expressed high levels of support for their consensus process. Keys to this committee’s success in reaching a high quality agreement were (i) a strong incentive to cooperate, (ii) consensus decision-making, and (iii) independent process facilitation. The latter two functioned as security measures against the potential for process manipulation by participants or governing agencies. Results from an examination of the broader committee indicate non-commercial respondents were largely accepting of an “oversight” role provided that the scope for their input remained sufficient, which it did not. Early involvement in tasks such as designing the process and defining objectives were particularly critical to non-commercial respondents’ perceptions of procedural fairness and their ability to participate effectively. Several participants also raised concerns that the process was not appropriately representative of groups with an interest in groundfish management. The poor performance of the process in these respects overshadowed positive aspects of broadening participation beyond commercial users. Consensus approaches have gained currency among commercial participants as a result of their positive experience and made some of them more willing to consider meaningful collaboration with a broader range of interest groups. The ineffectiveness of the broader committee suggests there is still work to do in designing processes that will actually achieve this meaningful, broad collaboration.
34

Cumulative effects thresholds for arctic grayling in the Wapiti River watershed

Norris, Adam Paul 22 January 2013 (has links)
Intensity and types of land use have changed rapidly in the last century and in north-western Alberta this has coincided with the decline of Wapiti River watershed Arctic Grayling (<italic>Thymallus arcticus</italic>) populations. Data on diurnal dissolved oxygen (DO), chemical and physical stream habitat data were collected in nine sub-watersheds of the Wapiti River with historically abundant Arctic Grayling populations. Levels and fluctuations of DO and temperature were related to the status of populations; five of the nine streams had higher temperatures and lower DO during summer, anoxic conditions during winter and extirpated populations. Amount of disturbed land and road density within sub-watersheds were inversely related to DO levels and population status. Cumulative effects modelling suggests a possible mechanism for these relationships is increased phosphorous runoff, leading to impaired habitat. These relationships and thresholds may be used as a management tool to maintain or restore Arctic Grayling and other stream fishes.
35

Regional and Local-Scale Population Genetic Structure of a Primitive Teleost, the African Bonytongue (Heterotis niloticus), in Rivers of West Africa

Carrera, Elizabeth 2012 August 1900 (has links)
The African bonytongue (Heterotis niloticus), one of two living species of the primitive teleost family Arapaimidae, constitutes an important artisanal and commercial fishery in West Africa. This species has also been proposed for wide aquaculture use in Africa. Despite its importance, information on the levels of genetic differentiation for this fish in Benin is lacking, which can contribute to its conservation and management. In this study, regional and local scale genetic differentiation of the African bonytongue in Benin, West Africa, was examined using six microsatellite markers. In total, 221 H. niloticus individuals were sampled from 12 localities in Benin that include three river basins: Oueme-So (ten localities sampled); Mono (one locality); and Niger (one locality). The results showed a high degree of genetic differentiation between African bonytongue samples from the three river basins, which was expected given the barriers for dispersal for aquatic organisms. For the Oueme-So floodplain, they indicate high and homogeneous gene flow, suggesting that seasonal flooding facilitates gene flow across this region. The information obtained from this study will be useful for defining management units for H. niloticus in Benin, and caution against the translocation of individuals from different basins.
36

A tale of two committees : evaluating collaborative management planning in Canada's Pacific groundfish fisheries

Davis, Neil 05 1900 (has links)
Governing agencies increasingly employ collaborative forms of decision-making in fisheries management to improve decision quality and legitimacy. However, crafting fair and effective collaborative processes which will achieve these benefits is often difficult. In an effort to identify keys and obstacles to success, this research evaluated the Commercial Groundfish Initiative, a collaborative planning process tasked with reforming the management of Canada's Pacific groundfish fisheries. Using semi-structured interviews, I gathered the perspectives of participants from the two committees within the process: a consensus-based committee of commercial representatives and a committee broadly representative of other interest groups for which consensus was encouraged but not mandated. Control over the design of a proposal for management reform was asymmetrically divided between the two committees, giving the commercial committee the primary role. Participants from the commercial committee expressed high levels of support for their consensus process. Keys to this committee’s success in reaching a high quality agreement were (i) a strong incentive to cooperate, (ii) consensus decision-making, and (iii) independent process facilitation. The latter two functioned as security measures against the potential for process manipulation by participants or governing agencies. Results from an examination of the broader committee indicate non-commercial respondents were largely accepting of an “oversight” role provided that the scope for their input remained sufficient, which it did not. Early involvement in tasks such as designing the process and defining objectives were particularly critical to non-commercial respondents’ perceptions of procedural fairness and their ability to participate effectively. Several participants also raised concerns that the process was not appropriately representative of groups with an interest in groundfish management. The poor performance of the process in these respects overshadowed positive aspects of broadening participation beyond commercial users. Consensus approaches have gained currency among commercial participants as a result of their positive experience and made some of them more willing to consider meaningful collaboration with a broader range of interest groups. The ineffectiveness of the broader committee suggests there is still work to do in designing processes that will actually achieve this meaningful, broad collaboration.
37

Using shell morphology to characterise abalone populations across multiple spatial scales.

Saunders, Thor M. January 2009 (has links)
Many sedentary marine invertebrates have a fine-scale (100s m) population structure that complicates their conservation and management. This is a consequence of the limited information on the boundaries between component populations and the biological variability among them. Blacklip abalone (Haliotis rubra) form discrete populations many of which are ‘stunted’ with individuals reaching a maximum length less than those in adjacent areas. A range of morphological measurements from samples of stunted and ‘non-stunted’ H. rubra collected from sites spread across broad (10s km) and fine (100s m) spatial scales in southern South Australia. In addition, information on the growth, size at maturity and fecundity of H. rubra was obtained from these same sites. The ratio between shell length and shell height showed clear and significant differences among samples from stunted and non-stunted sites. The fine-scale morphometric collections suggested that stunted populations existed at smaller spatial scales compared to those for non-stunted populations. Spatial variation in these key life history parameters could primarily be attributed to differences between stunted and non-stunted sites. Relationships between each of these parameters and the ratio between shell length and shell height were also examined. The spatial patterns in morphology and biology were highly correlated suggesting that shell length:shell height ratio can be used as a simple ‘morphometric marker’ to distinguish among populations of abalone and identify their biological characteristics. The detection of differences H. rubra morphology among variable environments cannot determine whether these differences represent a plastic response to the local environment, or whether morphology is genetically fixed. A reciprocal transplant experiment was used to test whether stunted H. rubra are the result of a plastic response to the environment or fixed genetic trait. Furthermore, environmental factors that affect food availability were related to differences in morphology. Morphological plasticity was confirmed as the mechanism causing morphological variation in H. rubra. Individuals transplanted to sites with non-stunted H. rubra grew significantly faster when compared to stunted controls, while individuals transplanted to stunted sites grew significantly slower compared to non-stunted controls. It is suggested that these differences are related to resource availability with areas limited in food supply resulting in stunted populations and areas with abundant food resulting in non-stunted populations. To reduce the risks of over-fishing and localised depletion of H. rubra, management units (MUs) that encompass individual populations need to be determined and then managed according to their life-history characteristics. Potential MUs in the South Australian abalone fishery were identified from the broad-scale, spatial distribution of stunted and non-stunted populations of H. rubra, by applying the morphometric marker to commercial shell samples. Key life-history parameters of the H. rubra populations within the potential MUs were estimated using relationships between this marker and H. rubra biology. Data from fine-scale systematic sampling by commercial fishers were used to validate spatial patterns observed from the more broadly distributed commercial catch samples. The location, distribution and size of potential MUs were largely inconsistent with that of current management. The locations of two MUs were consistent across the broad- and fine-scale datasets with the fine-scale samples being more informative for identifying a potential boundary between these. These results suggest that this morphometric marker can used as a tool for the spatial management of abalone fisheries by simply and inexpensively inferring key biological parameters for individual populations and identify the boundaries among these based on these differences. This approach is among the first to provide a practical means of more closely aligning the scales of assessment and management with biological reality for sedentary marine invertebrates. / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009
38

The biology of Samson Fish Seriola hippos with emphasis on the sportfishery in Western Australia.

andrew@recfishwest.org.au, Andrew Jay Rowland January 2009 (has links)
This thesis had two overriding aims. The first was to describe the biology of Samson Fish Seriola hippos and therefore extend the knowledge and understanding of the genus Seriola. The second was to uses these data to develop strategies to better manage the fishery and, if appropriate, develop catch-and-release protocols for the S. hippos sportfishery. Trends exhibited by marginal increment analysis in the opaque zones of sectioned S. hippos otoliths, together with an otolith of a recaptured calcein injected fish, demonstrated that these opaque zones represent annual features. Thus, as with some other members of the genus, the number of opaque zones in sectioned otoliths of S. hippos are appropriate for determining age and growth parameters of this species. Seriola hippos displayed similar growth trajectories to other members of the genus. Early growth in S. hippos is rapid with this species reaching minimum legal length for retention (MML) of 600mm TL within the second year of life. After the first 5 years of life growth rates of each sex differ, with females growing faster and reaching a larger size at age than males. Thus, by 10, 15 and 20 years of age, the predicted fork lengths (and weights) for females were 1088 (17 kg), 1221 (24 kg) and 1311 mm (30 kg), respectively, compared with 1035 (15 kg), 1124 (19 kg) and 1167 mm (21 kg), respectively for males. Despite these differences, female and male S. hippos attained similar maximum age, i.e. 29 (1470 mm FL) and 28 years (1280 mm FL), respectively. The maximum age determined for S. hippos is greater than that recorded for any other Seriola spp. The largest female and male S. hippos recorded during this study were encountered during the tagging component and had fork lengths of 1600 mm and 1380 mm, respectively. Seriola hippos has a protracted spawning period, ca four months, which starts in late spring and continues through summer into early autumn during which time many individuals engage in large spawning aggregations on the lower west coast of Australia. The length at which 50 % of the females in the population reached maturity was 831 mm FL (888 mm TL) and approximately 4 years of age, whilst all females over 950 mm FL were mature. Whilst aggregated for spawning S. hippos ceases feeding, however, during the non-spawning period this species can best be described as an opportunistic carnivore which feeds on a variety of pelagic and demersal prey. This study has greatly increased our understanding of S. hippos movement on the west and south coasts of Australia and has documented, for the first time, the migratory behaviour of a carangid in these waters. Many S. hippos individuals undertake long distance migrations to join spawning aggregation sites near Rottnest Island. Individuals tagged at these aggregation sites where recaptured throughout this species distribution along the south coast of Australia, some after travelling distances of over 2400 km. Many S. hippos individuals displayed strong temporal and spatial spawning ground fidelity as numerous fish released at the spawning aggregations were recaptured at the exact same spawning site at similar times in subsequent years. Tagging data suggest that on the completion of spawning S. hippos individuals return to a resident location and remain in that general vicinity over the winter months. This study has developed a hypothesis describing larval dispersal associated with the S. hippos spawning behaviour exhibited near Rottnest Island. It is proposed that variations in the prevailing ocean currents, at this important spawning location throughout the protracted spawning period, leads to high intra and inter-annual variation in larval distribution and survival. The affect of this variation on the evolution of the spawning and migratory behaviour displayed by S. hippos is discussed. A recent increase in the popularity of S. hippos as a catch-and-release sportfish has led to concerns by some anglers about post release survival of this species, particularly due to the depth of capture. Short term mortality of S. hippos capture at the sportfishing sites was assessed by monitoring fish held within an enclosure near the site of capture for up to 31 hours post release. The total hooking mortality of S. hippos subjected to catch-and-release angling within the Rottnest Island sportfishery is approximately 8%. Most of this observed mortality is delayed and occurs sometime after release. Although best handling practises require ongoing development, the current level of mortality associated with this catch-and-release fishery is considered acceptable. Furthermore, this mortality is likely to have little effect on the S. hippos population due to the high abundance of this species and the fact that even the highest fishing effort yields a relatively low catch. Seriola hippos exhibits a typical teleost neuroendocrine stress response associated with catch-and-release. The physiological dysfunction associated with the stress of capture in this species does not appear to cause any post release mortality. Instead, most mortality was attributable to barotrauma, however, although mortality in S. hippos increases with capture depth, this species is much less susceptible to depth induced mortality than other commonly targeted species in which barotrauma has been observed. This study developed key handling protocols for fishers who catch-and-release S. hippos at the Rottnest Island aggregation sites. These protocols cover aspects of catch-and-release fishing such as hook type, water depth, time at surface, release method and shark predation. Almost all S. hippos observed during capture from deep water released large quantities of gas from the opercular region, particularly during the last 10 to 20 m before reaching the surface. This phenomenon has also been witnessed by divers and fishers to occur under natural conditions. Investigations into this release of gas revealed this physoclistous species to exhibit unique swim bladder characteristics. Seriola hippos possess a membranous tube that connects the posterior-dorsal surface of the swim bladder internally to a region under each operculum externally. This connection, termed the swim bladder vent, allows the escape of expanding swim bladder gases on rapid ascent. The presence of the swim bladder vent provides an explanation as to why the incidence of external barotrauma symptoms in S. hippos captured from the deepwater was low. The ability to expel excess swim bladder gases during rapid ascent whilst retaining full swim bladder function is likely to offer this semi-pelagic species considerable advantages when hunting prey, avoiding predators and engaging in spawning activities. Preliminary estimates of total mortality indicated that S. hippos is not currently subjected to a high level of fishing pressure. However, managers must remain mindful of the fact that the size at which females reach sexual maturity, i.e. 888 mm TL, is greater than the current minimum legal length, i.e. 600 mm, and thus fishers are currently allowed to harvest sexually immature fish. Furthermore, the effectiveness of future conservation measures must consider the large scale migration and spawning strategy undertaken by this species in order to ensure its protection. The collaborative research approach undertaken during this study demonstrated that a high level of community engagement produced a large amount of research interest, increased stakeholder satisfaction from project input, improved understanding of research outcomes, and increased research uptake, all of which has led to increased stewardship and conservation of the S. hippos fishery and fisheries resources in general. Indeed, projects of this nature would not be possible without this type of approach.
39

Risk analysis of a flatfish stock complex : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Mathematics at Massey University

McLeod, Kristin January 2010 (has links)
The New Zealand Ministry of Fisheries relies on fishery assessments to determine suitable catch quotas for exploited fisheries. Currently, 628 fish stocks are managed in New Zealand using the Quote Management System, which includes the 8 com- mercial flatfish species caught within the Exclusive Economic Zone. These eight species of flatfish, which includes four species of flounder, two species of sole, brill and turbot, are currently managed using a combined catch quota. Since these eight species are managed using a common catch quota, there is concern that some of the individual species may be under or over-fished. This thesis describes work involving the flatfish species caught in the FLA3 man- agement area, around the south island of New Zealand. The FLA3 management area contains three key species: New Zealand sole, lemon sole, and sand flounder. Due to the nature and limitations of the data available, simple biomass dynamic models were applied to these species. The maximum likelihood and Bayesian goodness of fit techniques were used to estimate the model parameters. Three models were used: the Fox model, the Schaefer model and the Pella-Tomlinson model with m = 3. As a mathematical/statistical exercise, these models were used to conduct a risk analysis to analyse the advantages and disadvantages of six management options for setting a TACC. However, because of issues over the way that the parameter K has been modelled (due to necessity caused by the lack of data), this should not be seen as an appropriate method for estimating the fish stock. Conclusions were drawn from the results regarding suitable future action for the assessment and management of flatfish stock in FLA3.
40

Prawners, prawning and policies: The management of the Queensland prawn fishery 1970-1995

Glaister, John Patrick Unknown Date (has links)
No description available.

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