Affiner votre recherche
Résultats 1-10 de 1,277
Study on aquatic ecology to generate guideline for fisheries conservation in wetland of Nong Bong Khai Non–Hunting area, Chiang Rai province | การศึกษานิเวศวิทยาทางน้ำเพื่อกำหนดแนวทางการอนุรักษ์ประมงในพื้นที่ชุ่มน้ำ เขตห้ามล่าสัตว์ป่าหนองบงคาย จังหวัดเชียงราย Texte intégral
2010
Kwanruen Yodkham(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Fisheries Management) | Sukhoom Rowchai(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Fisheries Management) | Idsariya Wudtisin(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Fisheries Management)
Community readiness for participation and role of community for fishery management: A case study in Haiphong province, Vietnam
2010
Nguyen Quoc Anh(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Fisheries Management) | Sangtien Ajjimangkul(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Fisheries Management) | Kungwan Juntarashote(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Fisheries Management) | Shettapong Meksumpum(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Marine Science) | Jantra Srisomwong(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Fisheries Management) | Urairat Netharn(Kasetsart University, Bangkok (Thailand). Faculty of Fisheries. Department of Fisheries Management)
Fisheries management
2010
Girdler, Ashley | Wellby, Ian | Welcomme, R. L.
The book's first part covers the ecology of still waters and includes information on physical and chemical processes, nutrient cycles, energy movements, trophic levels, bacteria, plants, invertebrates, fish, disease-causing organisms, mammals and birds. Part two provides in depth information, on how a still-water fishery should be set up, developed and successfully managed. Coverage includes development, preparation and construction; stock assessment and invertebrate survey; control of water quality, aquatic plants, erosion, predators and nuisance species; management of the impact of climate change; fish disease and biosecurity; control of fishing activities, fish nutrition, fishery enhancement and condition improvement, and general administration. The final part of this manual covers legal and social frameworks including general and environmental legislation, direct fisheries-related legislation, and agencies and organizations.
Afficher plus [+] Moins [-]Changes in frigate tuna populations on the south coast of Sri Lanka: evidence of the shifting baseline syndrome from analysis of fisher observations Texte intégral
2010
Venkatachalam, A.J. | Price, A.R.G. | Chandrasekara, S. | Senaratna Sellamuttu, S. | Kaler, J.
Changes in frigate tuna populations on the south coast of Sri Lanka: evidence of the shifting baseline syndrome from analysis of fisher observations Texte intégral
2010
Venkatachalam, A.J. | Price, A.R.G. | Chandrasekara, S. | Senaratna Sellamuttu, S. | Kaler, J.
1.This study examines changes in frigate tuna populations in southern Sri Lanka, based on reports from fishers in three age classes. Significantly higher values for best day's catch and largest specimen ever caught were obtained by older fishers than younger ones. Values were also significantly higher during early years, providing clear evidence of a decrease in the resource over time (1951-2007).2.Older fishers reported best catches further inshore and in shallower waters which, on becoming depleted, forced younger generations to fish in less exploited areas further offshore. Heavy harvesting is also evident from the significantly greater number of sites reported by older fishers as being depleted, compared with observations of younger fishers.3.These findings contrast markedly with catch and catch per effort patterns from statistics for frigate tuna and bullet tuna (combined) in southern Sri Lanka (1994-2004). No stock decline is evident, and at least one report in the early 1990s advocated increasing exploitation rates by 40% to maximize yields.4.Although not a primary research objective, fisher observations on frigate tuna populations were also analysed to help evaluate possible effects of the 2004 tsunami. Most fishers reported post-tsunami decline, but mainly from a larger new generation of fishers, rather than extra boats provided by aid money or (direct or indirect) biophysical impacts from the tsunami.5.Reliance on fishery statistics, especially for mixed species and over a limited period, can be risky and easily mask true stock status. Evidence of harvesting effects on frigate tuna in southern Sri Lanka is evident using questionnaire data over a longer time scale.6.This study provides another compelling case of the 'shifting baseline syndrome', whereby fishers of different ages have altered perceptions/experiences of their environment. This may be its first reported occurrence in Sri Lanka. Traditional knowledge from this and similar surveys may provide national fishery management with valuable insights and help improve conservation prospects for frigate tuna and other marine resources.
Afficher plus [+] Moins [-]Changes in frigate tuna populations on the south coast of Sri Lanka: evidence of the shifting baseline syndrome from analysis of fisher observations Texte intégral
2010
Venkatachalam, A.J. | Price, A.R.G. | Chandrasekara, S. | Senaratna Sellamuttu, Sonali | Kaler, J.
This study examines changes in frigate tuna populations in southern Sri Lanka, based on reports from fishers in three age classes. Significantly higher values for best day's catch and largest specimen ever caught were obtained by older fishers than younger ones. Values were also significantly higher during early years, providing clear evidence of a decrease in the resource over time (1951-2007). Older fishers reported best catches further inshore and in shallower waters which, on becoming depleted, forced younger generations to fish in less exploited areas further offshore. Heavy harvesting is also evident from the significantly greater number of sites reported by older fishers as being depleted, compared with observations of younger fishers. These findings contrast markedly with catch and catch per effort patterns from statistics for frigate tuna and bullet tuna (combined) in southern Sri Lanka (1994-2004). No stock decline is evident, and at least one report in the early 1990s advocated increasing exploitation rates by 40% to maximize yields. Although not a primary research objective, fisher observations on frigate tuna populations were also analysed to help evaluate possible effects of the 2004 tsunami. Most fishers reported post-tsunami decline, but mainly from a larger new generation of fishers, rather than extra boats provided by aid money or (direct or indirect) biophysical impacts from the tsunami. Reliance on fishery statistics, especially for mixed species and over a limited period, can be risky and easily mask true stock status. Evidence of harvesting effects on frigate tuna in southern Sri Lanka is evident using questionnaire data over a longer time scale. This study provides another compelling case of the 'shifting baseline syndrome', whereby fishers of different ages have altered perceptions/experiences of their environment. This may be its first reported occurrence in Sri Lanka. Traditional knowledge from this and similar surveys may provide national fishery management with valuable insights and help improve conservation prospects for frigate tuna and other marine resources.
Afficher plus [+] Moins [-]Changes in frigate tuna populations on the south coast of Sri Lanka: evidence of the shifting baseline syndrome from analysis of fisher observations Texte intégral
2010
Venkatachalam, A.J. | Price, A.R.G. | Chandrasekara, S. | Senaratna Sellamuttu, Sonali | Kaler, J.
This study examines changes in frigate tuna populations in southern Sri Lanka, based on reports from fishers in three age classes. Significantly higher values for best day's catch and largest specimen ever caught were obtained by older fishers than younger ones. Values were also significantly higher during early years, providing clear evidence of a decrease in the resource over time (1951-2007). Older fishers reported best catches further inshore and in shallower waters which, on becoming depleted, forced younger generations to fish in less exploited areas further offshore. Heavy harvesting is also evident from the significantly greater number of sites reported by older fishers as being depleted, compared with observations of younger fishers. These findings contrast markedly with catch and catch per effort patterns from statistics for frigate tuna and bullet tuna (combined) in southern Sri Lanka (1994-2004). No stock decline is evident, and at least one report in the early 1990s advocated increasing exploitation rates by 40% to maximize yields. Although not a primary research objective, fisher observations on frigate tuna populations were also analysed to help evaluate possible effects of the 2004 tsunami. Most fishers reported post-tsunami decline, but mainly from a larger new generation of fishers, rather than extra boats provided by aid money or (direct or indirect) biophysical impacts from the tsunami. Reliance on fishery statistics, especially for mixed species and over a limited period, can be risky and easily mask true stock status. Evidence of harvesting effects on frigate tuna in southern Sri Lanka is evident using questionnaire data over a longer time scale. This study provides another compelling case of the 'shifting baseline syndrome', whereby fishers of different ages have altered perceptions/experiences of their environment. This may be its first reported occurrence in Sri Lanka. Traditional knowledge from this and similar surveys may provide national fishery management with valuable insights and help improve conservation prospects for frigate tuna and other marine resources.
Afficher plus [+] Moins [-]A Case Study in Successful Management of a Data-Poor Fishery Using Simple Decision Rules: the Queensland Spanner Crab Fishery
2010
Dichmont, Catherine M. | Brown, Ian W.
The Queensland spanner crab Ranina ranina is the target of a relatively data-poor, low-value fishery that has been managed for the last decade by using total allowable catches (TACs) in an individual transferable quota system. Despite the fact that this management system is usually applied to data-rich fisheries, it has been successfully used on this data-poor fishery. The key factor has been the use of harvest strategies that consisted only of simple decision rules that were appropriate given the size of the fishery and knowledge of the resource. These strategies were tested in a management strategy evaluation framework; however, it was not traditional in that (1) the operating model (or ““true”” resource to be managed) was not conditioned to data but rather was set to parameter ranges seen as appropriate for the resource and (2) the TAC was not set by using a stock assessment model, so the magnitude of the stock biomass was unknown. The important test was whether one could develop harvest strategies that were robust to this large uncertainty in knowledge by using only commercial catch rates. The management system had to be adaptive over time as more was learned about the biology of the species and how the harvest strategies affected the management of the fishery. This meant that the TAC was almost always set using the harvest strategies, but modifications to the decision rules were made on several occasions as more was learned about the fishery. The transparency and simplicity of the rules mean that the industry was empowered to make significant contributions to fine tuning the harvest strategies. As a result, the process does not rely solely on scientific advances but on the pooled knowledge of scientists, industry, and managers in a cooperative environment.
Afficher plus [+] Moins [-]Ecological indicators display reduced variation in North American catch share fisheries Texte intégral
2010
Essington, Timothy E.
A growing push to implement catch share fishery programs is based partly on the recognition that they may provide stronger incentives for ecological stewardship than conventional fisheries management. Using data on population status, quota compliance, discard rates, use of habitat-damaging gear, and landings for 15 catch share programs in North America, I tested the hypothesis that catch share systems lead to improved ecological stewardship and status of exploited populations. Impacts of catch share programs were measured through comparisons of fisheries with catch shares to fisheries without catch shares or by comparing fisheries before and after catch shares were implemented. The average levels of most indicators were unaffected by catch share implementation: only discard rate, which declined significantly in catch share fisheries, showed a significant response. However, catch share fisheries were distinguished by markedly reduced interannual variability in all indicators, being statistically significant for exploitation rate, landings, discard rate, and the ratio of catch to catch quotas. These impacts of catch shares were common between nations and ocean basins and were independent of the number of years that catch share programs had been in place. These findings suggest that for the indicators examined, the primary effect of catch shares was greater consistency over time. This enhanced consistency could be beneficial to fishery systems and might also be an indication of more effective management.
Afficher plus [+] Moins [-]Reform Drivers and Reform Obstacles in Natural Resource Management: The Northeast Atlantic Fisheries from 1945 to the Present Texte intégral
2010
Gezelius, Stig S. | Raakjær, Jesper | Hegland, Troels Jacob
The ability to transform historical learning into institutional reform is a key to success in the management of common pool natural resources. Based on a model of institutional inertia and a comparative analysis of Northeast Atlantic fisheries management from 1945 to the present, the paper aims to identify drivers and obstacles to learning-based institutional reform. We argue that the ineffectiveness of implementation systems has been a key driver of reform requirements, but that the need for agreement amongst a large number of interdependent decision makers has been an obstacle to required reform. In such situations, distribution systems, especially, tend to become important obstacles to reform. Institutional inertia tends to be reinforced by tacit discourse frames: however, strong tensions between institutional inertia and needs for reform may also create room for innovation. Institutional inertia entails that large-scale management reform tends to be crisis driven.
Afficher plus [+] Moins [-]Governance and decentralization reforms in small-scale fisheries: an African perspective Texte intégral
2010
c | bã©nã©
Relying on a framework that highlights different dimensions of â??decentralizationâ??, this paper reviews fisheries co-management programmes as they have been implemented over the last 20 years in sub-Saharan Africa. It shows that in most cases, fisheries co-management programmes failed to improve governance, but simply altered the distribution of power and responsibility amongst the different stakeholders. In this new context, the co-management programmes were implemented often at the detriment of the direct endusers (fisherfolk) who benefit from those reforms only in a limited number of cases. Challenging the current narrative that presents participation as the central condition for governance reforms, the review instead highlights the importance of downward accountability. The paper concludes with a series of recommendations | Béné, C. (2009) p. 253-266. In: Wramner P., M. Cullberg and H. Ackefors (eds.) Fisheries, sustainability and development. Royal Swedish Academy of Agriculture and Forestry, Stockholm. (open access)
Afficher plus [+] Moins [-]Fisher-Collected Sampling Data: Lessons from the New Zealand Experience
2010
Starr, Paul
The New Zealand fishing industry has adopted a strategy of using fishers to collect biological sampling data from their fisheries, usually on a voluntary basis. This approach can be adopted for data-poor fisheries to obtain data that would otherwise not be available. This article describes a wide range of such programs implemented in fisheries spanning a period of 15 years. This article also reveals the designs employed, how these data have been used in stock assessment and fisheries management situations, and some of the problems encountered in administering these programs. I conclude that while these programs need supervision and support in order to succeed, the benefits that can accrue are considerable. These benefits include a dynamic sampling design that should ensure good representation of the fishery and the involvement of fishers in collecting the data used to manage their fishery.
Afficher plus [+] Moins [-]Age and growth, mortality and reproduction of the striped sea bream, Lithognathus mormyrusLinnaeus 1758, from the south coast of Portugal (Algarve) Texte intégral
2010
Monteiro, Pedro | Bentes, L. | Coelho, Rui | Correia, Carla | Erzini, Karim | Lino, Pedro | Ribeiro, Joaquim | Gonçalves, J. M. S.
The striped sea bream, Lithognathus mormyrus, used for this population dynamics study were obtained from longline catches and market sampling in the Algarve (south Portugal). The macroscopic analysis of the gonads and the gonad somatic index showed that the south Portuguese population of L. mormyrus spawns mainly between late spring and summer (June to August). The length at first maturity was similar for males and females and the value for both sexes combined was estimated to be 16.08 cm, corresponding to an age between 1 and 2 years. Fish age classes (0 to 13) were determined by reading growth rings on whole otoliths. Age determination was validated by marginal increment analysis. The estimated parameters of the von Bertalanffy growth equation were L∞=35.30 cm, K=0.264 and t 0= − 0.809. Mortality rates were calculated for fish captured with longlines, and the estimated parameters were M=0.356, Z=0.622 and F=0.266. From an Algarve fishery management perspective, these results suggest the need for an increase in the minimum landing size (from 15 to 17 cm), which should be beneficial for the sustainability and conservation of this species. The results also showed that fishing with longlines off the Algarve coast may allow for a sustainable use of the resource. | info:eu-repo/semantics/publishedVersion
Afficher plus [+] Moins [-]