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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.
11

An assessment of the South African east coast linefishery from Kei Mouth to Stil Bay

Brouwer, Stephen Leonard January 1998 (has links)
During the period April 1994 and February 1996 as part of an investigation into the national Iinefishery, the east coast shore fishery and the recreational and commercial ski-boat fisheries were surveyed, at eight sites between Kei Mouth in the East and Stil Bay in the West. Roving creel, access point and aerial surveys were used. A questionnaire was developed for each sector to gather data on catch and effort, fisher demographics, economics, fisher attitudes towards, and knowledge of, the current management regulations and assess the efficacy of the fisheries inspectorate. During the access point survey the catch of 3273 fishers was inspected and 1556 interviews were conducted. Questionnaires were conducted on 118 recreational ski-boaters and the catch of 165 boats was inspected. 96 commercial skippers were interviewed and 230 had their catch inspected. Three aerial surveys of the entire area were conducted during which a total of 1067 shore fishers were counted giving a shore fisher density of 0.39 fishers.km⁻¹. The majority (99%) of participants in all sectors of the linefishery were male. The greatest number of participants were white, shore fishery 77% recreational ski-boat 98% commercial skiboat 89%, followed by coloured, asian and black people. To a large extent this reflects the income of various racial groups. Most fishers supported the current linefish management plan. However, when tested on their knowledge of the size limits, bag limits and closed seasons of their target species many shore fishers (59%) did not know them and a high proportion of fishers in all sectors had disobeyed at least one of the regulations (shore 50%, recreational ski-boat 70%, commercial ski-boat 56%). When compared to historical data the present catch per unit effort (CPUE) in all sectors has decreased. Most interviewees in the various sectors did not accept responsibility for the decline in CPUE, but attributed it to three principal reasons vis their perceived direct competitors, trawling and pollution. Analysis of the catch revealed that all sectors were multispecies fisheries, with each sector being characterised by a small number of target species. Catch composition differed significantly between the shore and ski-boat sectors, but there was significant overlap between the two skiboat sectors. Analysis of the catch in comparison to that reported to the National Marine Linefish System (NMLS) revealed that there was a substantial degree of under-reporting. There was little seasonal difference in effort in the shore fishery while the recreational ski-boat effort was highest in the summer and the commercial ski-boat effort was high in the winter. Effort in the shore and recreational ski-boat fisheries was concentrated over weekends while the commercial ski-boat effort was highest during weekdays. Total effort for the entire area was estimated at 903 186 (±1913) fisher days per annum in the shore fishery, 24 357 (±685) recreational ski-boat fisher days and 64 266 (±1686) commercial ski-boat fisher days. Expenditure and capital investment in the various sectors was calculated, as were earnings of the participants in the commercial ski-boat sector. The linefishery in the Eastern Cape was estimated to have a minimum capital investment in excess of R210 million and more than R32 million is spent annually on running costs. The commercial ski-boat fishery directly employed an estimated 3184 people. The economic implications of changes in CPUE for the commercial ski-boat fishery are considered, as are the benefits of a recreational angling licence. Management of the linefishery is discussed in relation to the findings of this study.
12

Cooperative fishery and wildlife research units program outputs

Mayer, Suzanne January 1982 (has links)
The Cooperative Fishery and Wildlife Research Units program is a federal-state-private cooperative program of training, research, and technical assistance. Formally authorized by Congress in 1960, the program actually began 26 years earlier with establishment of wildlife units at land grant universities in Virginia, Oregon, and Iowa. Each unit, of which there are 50 today, functions under a cooperative agreement involving the U.S. Fish and Wildlife Service, the state conservation agency, the university where the unit is located and the Wildlife Management Institute (wildlife units and combined fishery and wildlife units only). In recent years the program has been criticized as not being a truly cooperative media for research, education, and public services that meet the needs of cooperators and produce the intended benefits. In addition, particularly at the federal level, the program has not fared well in competition with other programs for limited manpower and financial resources. Before effectiveness of a program can be judged or justified, its inputs and outputs must be understood, not only in terms of quantity, but also in terms of quality. This study, through literature review, questionnaires, letters and personal interviews attempts to: 1) identify and define unit outputs; 2) develop criteria for measuring the quality and quantity of the outputs; 3) integrate output data into a method for evaluating effectiveness; and 4) provide cooperators in the program with a methodology for program evaluation. The study does not involve an actual program evaluation or justification. Rather, it provides cooperators with a methodology for program evaluation. / Master of Science
13

Recreational specialization as an indicator of attitudes and management preferences of Virginia river anglers

Chipman, Brian D. January 1986 (has links)
The angling public is a heterogenous aggregation of subgroups with differing value systems; therefore, fisheries managers must identify the subgroups and their corresponding attributes to guide management programs. This study was designed to evaluate the concept of recreational specialization for differentiating angler subgroups, and to determine if angler attitudes and management preferences vary predictably by specialization level. Specialization was defined as a continuum of angler behavior, from general to specialized, along four dimensions: (1) fishery resource use, (2) degree of experience, (3) investment, and (4) the relationship of angling to the lifestyle. In 1984-85, 544 anglers on the Shenandoah and New Rivers, Virginia, were interviewed and asked to participate in a followup mail survey. Of those who agreed, 379 anglers returned completed questionnaires (80% response rate). Cluster analysis of respondents, using variables in each of the four dimensions, identified six distinct angler types, ranging from low to high specialization. As expected, occasional and generalist anglers cited escape and family-oriented motivations, placed greater emphasis on luck to catch fish, were satisfied with catching and harvesting smaller fish, and favored liberal harvest regulations. Specialists were more likely to cite resource-oriented motives (testing skills, trophy fishing), to rely on skill to catch fish, preferred to catch and release larger fish, and favored restrictive harvest regulations. The results show that relatively simple and objective surveys of angler behavior can substitute for attitude surveys and can indicate how programs should be managed to maximize angler satisfactions. / M.S.
14

Modelling to compare harvest regulations in recreational fisheries: case study of smallmouth bass fisheries

Wagner, Brian Keith 25 August 2008 (has links)
Negative binomial distributions were fitted for ten sets of complete trip creel survey data from the New and Shenandoah Rivers in Virginia and West Virginia. The fits for eight of ten datasets were not significantly different from the observed distributions (P< 0.05). The negative binomial provides a good alternative when complete trip data are unavailable or unreliable; however it was still more accurate to use the observed frequency distributions. An age-structured, non-linear population model employing instantaneous mortality rates was developed to compare the merit of various regulation schemes. Model outputs included parameters commonly measured in recreational fisheries management, including structural indices, catch, harvest, and yield. Eight creel limits (1-8 fish/angler-day) and ten length limits (six minimum limits, three slot limits, and no length limit) were simulated in all possible combinations. A catch-and-release scenario was also simulated, increasing the total number of simulations to 81. As a case study, data were used from the smallmouth bass fishery in a pool of the New River in West Virginia. Principal components analysis revealed that 91% of the total variation in the output variables among the 81 simulations was represented by the first three components. A set of seven variables maximized the differences among simulations: harvest (numbers), size harvested, catch (numbers), size caught, proportional stock density, relative stock density of trophy fish, and yield (weight). Model results for these individual variables revealed that, while harvest and yield were maximized by liberal scenarios, all other variables were improved by the more restrictive regulations. The results also indicate that minimum length limits have a much greater impact than creel limit reductions. / Master of Science
15

An ecological analysis of the quality fishery for rainbow trout in Becker Lake

Satterthwaite, Thomas Dee, 1953- January 1978 (has links)
No description available.
16

Site selection and community participation in the development of Gracilaria Gracilts (stackhouse) steentoft, irvine and farnham mariculture in the Western Cape province, South Africa.

Brown, Bernadette January 1999 (has links)
Magister Artium (Development Studies) - MA(DVS) / The seaweed Gracilaria gracilis has been shown in previous studies to have potential for mariculture along the West Coast of South Africa. However, the selection of suitable sites is crucial for the success of a farming enterprise. The variables important in the success or sustainability of suspended raft culture, and the environmental factors influencing these variables, were identified through a literature review. A suitable site was defined as a site with surface water temperature of between 10 and 17 "C, water depth of between 2 and 10 m below surface, and wave heights of less than 4 m. Data and information about these factors were obtained from sources such as the Sea Fisheries Research Institute, the SADCO database, the CSIR and from volunteers in St Helena Bay. The objectives of this study were to convert available data into formats that could be used in a Geographical Information System (GIS), and to predict suitable and available sites for suspended cultivation of Gracilaria gracilis in Saldanha Bay, Langebaan Lagoon and St. Helena Bay. Data were converted to digital format and data layers created. Each data layer represented suitable and unsuitable areas. Areas with existing mariculture, harbours, ship traffic zones and other uses were excluded to determine the real available areas. The Saldanha Bay-Langebaan lagoon system and St Helena Bay, have sites that show potential for suspended cultivation of G. eracilis. The total sizes of the areas selected as suitable are 975.4 ha in Saldanha Bay and 474.8 ha in St. Helena Bay. Some sites predicted as suitable are located in areas known to be subject to conditions not suitable for seaweed mariculture, and led to the conclusion that the accuracy of input data or method of analysis must be improved.
17

An evaluation of the Hirgigo Fishing Training Centre : the role of training in socio-cultural development of traditional fisheries in Eritrea.

Alamin, Hassan Hassaballah January 2005 (has links)
In a bid to support the harvesting of marine resources amongst the rural coastal communities and fishing sectors of Eritrea; the traditional fishermen of the coastal and island communities of this country have been involved in formal training regarding their fishing skills. The training programmes are intended to transfer fishing knowledge to the traditional fishermen of coastal communities and to introduce appropriate basic fishing skills through the Hirgigo Fishing Training Centre (HFTC). This study analyses the perceived role of the fishing training programme in improving fishing activities. The study further evaluates the HFTC programme, from the perspective of its 'traditional fishermen' target audience. Criteria for the observation and the focal point of the analysis, is to reveal ways in which to best contribute to the development of the fishing villages. This research therefore poses the following question: Is the current training sufficient to develop fishing livelihoods in rural coastal fishing communities, so improving the lives of the people in the fishing villages of Eritrea - or is a greater socio-cultural understanding of the fishing communities required, complimented by subsequent grass-roots development? In order to answer this question, the study will depend upon the perceptions of key informants and trained fishermen - which are used to examine the impact of the training centre and its programmes. In order to evaluate the HFTC training programme, the study applies a mixture of evaluative social research using the 'naturalistic model' as well as 'Participatory Rural Appraisal' (PRA) research methodologies. The data collection and analysis of the research study is based upon qualitative research methods. Traditional Eritrean coastal fishing life is based upon traditional knowledge, customs, religion, culture and behavioural experiences that emphasise the flexibility of livelihoods amongst rural shore inhabitants - over many generations. It is suggested that, as a consequence, the training and development programme faces difficulties in penetrating the inherent characteristics of traditional fishing. The study shows that while the training programme curricula and instructors' teaching methods are appropriate for the traditional fishermen, they cannot adequately address the everyday constraints experienced by these individuals and their communities. Traditional fishermen are dependent upon multiple livelihoods. While the research participants perceived fishing as a very important way of making a living (as opposed to other livelihoods) they are not willing to rely exclusively on fishing. This study further shows that Eritrean fishing communities are rooted in traditional attitudes and have unique socio-cultural characteristics. As a research area, the social and cultural milieu of coastal communities is fascinating and requires further social research studies; as does the context of social organisations in coastal and island communities, their indigenous knowledge, culture and ecology. These require special attention to assist rural coastal and island communities and develop academic social and cultural studies. / Thesis (M.Soc.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005
18

Habitat use by fishes of the New River, West Virginia

Lobb, M. Delbert January 1986 (has links)
Density estimates of the species and life stages in different habitat types were made from electrofishing collections and underwater fish counts. During midday, fish densities in edge pool and riffle habitats were comparable, but densities in edge pool habitat were significantly higher than densities in middle pool and run habitats. Snag and edge riffie habitats supported the highest densities of fish. Habitat use and activity shifts between daytime and nighttime were found for many species. Fish species and lifestage composition and densities differed among the habitat types, and five habitat-use guilds (edge-pool, middle-pool, edge-channel, riffie, and generalists) were described. Larger centrarchids preferred deep habitats with slow velocities (deep edge and middle pool, and snags), while young centrarchids preferred shallower habitat. However, all sizes of smallmouth bass were nearly ubiquitous in the habitats of the study area. The cyprinids and percis preferred shallow areas, but preferences for velocity differed among the species and lifestages. Spawning and habitat preferences of the endemic bigmouth chub, Nocomis platyrhynchus, were described. Bigmouth chubs used areas with plenty of small to large gravel (3-64 mm diameter), shallow depths, and moderate velocities for constructing spawning mounds. Bigmouth chubs were seen only using riffie and adjacent run habitat during late summer. Within these areas, depth, velocity, substrate, and cover were used in accordance with their availability, except for an avoidance of the shallowest available depths. Bigmouth chubs occupied positions near the substrate, where velocities were slower than the mean water column velocity. / M.S.
19

A cooperative effort to track Humboldt squid invasions in Oregon

Chesney, Tanya A. 04 September 2012 (has links)
Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing their range expansion from Mexico is poorly understood due to the recent nature of their "invasion" and a lack of monitoring. Humboldt squid are large predators that have the potential to affect ecosystem structure and fisheries because of their high-energy demands and ability to exploit a variety of oceanographic conditions and prey sources. Developing baseline distribution information is a critical first step to assess their potential ecological, social, and economic impacts, and to develop models to predict future range expansion. This study has two main objectives: (1) to document where and when Humboldt squid have been present in Oregon through cooperative fisheries research, and (2) to correlate the sightings with oceanographic conditions using a geographic information system (GIS) and species distribution modeling (SDM). I conducted 54 interviews with local fishermen and aggregated their squid sightings with available fishery-independent survey and fishery-dependent observer data from the National Marine Fisheries Service. I compiled a total of 339 Humboldt squid sightings, reported for the years 2002-2011 from the Oregon coast to 131�� west longitude. Correlation analyses were performed for Humboldt squid sightings and sea surface temperature (SST), chlorophyll a content (chla), sea surface height anomalies (SSH), dissolved oxygen at 30 m depth (30 m DO), and sea surface salinity (SSS) using a GIS, nonparametric multiplicative regression (NPMR) habitat modeling, and maximum entropy modeling (Maxent). Results indicate that oceanographic conditions have the potential to influence Humboldt squid occurrence, and in Oregon, sightings vary temporally and spatially. Combining the sightings from fishermen and scientific surveys greatly enhanced the spatial extent of the data. Humboldt squid were most frequently observed between 124.4��W and 125��W in proximity to the shelf-break at the 200 m isobath, with peak sightings (116) recorded in 2009 and the fewest (6) reported in 2003 and 2011. The highest occurrence of Humboldt squid were observed at a SST of 10.5-13.0��C, 0.26-3.0 mg m����� chla content, -4.0-1.0 m SSH anomalies, 32.2-32.8 psu SSS, and at 3-4.5 ml L����� and 6-7 ml L����� 30 m depth DO. Maps of estimated likelihood of occurrence generated by NPMR were consistent with overlayed observations from fishermen, which were not used in the model because they were limited to presence-only information. An interdisciplinary approach that incorporates cooperative fisheries research and ecosystem-based management is necessary for monitoring Humboldt squid in Oregon. Traditional methods are insufficient because Humboldt squid are data-poor, highly migratory, and are main predators of many commercially important fisheries in Oregon. Based on my findings, sightings recorded by fishermen covered a much larger area over a longer time frame than the scientific survey and observer data, and excluding their knowledge would have led to a different interpretation of Humboldt squid distribution and environmental tolerances. Although there is uncertainty in the data from potential map bias or misidentification of smaller Humboldt squid, incorporating sightings from fishermen with traditional fisheries research increases the quantity and quality of information. Cooperative monitoring for Humboldt squid could include training in species identification and sea condition reporting in logbooks. Future "invasions" are likely, and more eyes on the water will improve our understanding of the behavior and impacts of Humboldt squid on coastal resources. / Graduation date: 2013
20

Sea Change

Vice President Research, Office of the January 2009 (has links)
As political debate over the overexploitation of fish stocks rages on, UBC’s Fisheries Centre is targeting the responsible management of aquatic ecosystems from multiple perspectives.

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