Recent Submissions

  • Women in aquaculture

    Brugere, C.; Felsing, M.; Kusakabe, K.; Kelkar, G. (Institute of Aquaculture, University of Stirling, 2001)
    [PDF contains 61 pages]
  • An approach to valuing ponds within farming systems for aquaculture

    Brugere, C.; Little, D. (Institute of Aquaculture, University of Stirling, 2000)
    [PDF contains 37 pages]
  • Control of bacterial disease in small scale fresh-water aquaculture: Project R0754. Project completion report December 1998 - May 1999

    Thompson, K.; Crumlish, M. (Institute of Aquaculture, University of Stirling, 1999)
    The work presented here represents an 18-month study to examine the relationship between environmental conditions, bacterial load in the water and bacteria levels in tissue macrophages of a range of clinically healthy freshwater fish species, farmed in a range of culture systems in Thailand and Vietnam. Preliminary assessment was made of the clinical significance of the macrophage bacterial load. The aim of this work was to improve production in fresh-water aquaculture through the control of clinical bacterial disease and subclinical infection, and to identify management practices most effective in promoting fish health. [PDF contains 37 pages]
  • Fisheries marketing systems and consumer preferences in Puttalam District Sri-Lanka

    Murray, F.J.; Little, D.C. (Institute of Aquaculture, University of Stirling, 2000)
    The aim of this study was to understand the current and historic market situation for inland fish and it’s substitutes in order to identify which of the various production opportunities presented by the seasonal tank resource might have greatest relevance for marginalcommunities in the Dry-zone. Regional and sub-regional market networks for fish and meat products were investigated, ranking and scoring exercises used to characterise consumer demand in rain-fed areas of North West Province and secondary data sources were used to assess historic patterns of demand and supply [PDF contains 57 pages]
  • Nutrient dynamics of seasonal tanks in the dry zone of Sri Lanka in relation to their hydrological regimes

    Jayakody, B.V.P.L.; Murray, F.J.; Little, D.C.; Mowjood, M.I.M. (Institute of Aquaculture, University of Stirling, 2002)
    Village tanks are put to a wide range of uses by the rural communities that depend on them for their survival. As the primacy of irrigation has decreased under these tanks due to a variety of climatic and economic reasons there is a need to reevaluate their use for other productive functions. The research presented in this paper is part of a programme investigating the potential to improve the management of living aquatic resources in order to bring benefits to the most marginal groups identified in upper watershed areas. Based on an improved typology of seasonal tanks, the seasonal changes and dynamics of various water quality parameters indicative of nutrient status andfisheries carrying capacity are compared over a period of one year. Indicators of Net (Primary) Productivity (NP): Rates of Dissolved Oxygen (DO) change, Total Suspended Solids (TSS): Total Suspended Volatile solids (TVSS) ratios are the parameters of principle interest. Based on these results a comparative analysis is made on two classes of ‘seasonal’ and ‘semi-seasonal’ tanks. Results indicate a broad correlation in each of these parameters with seasonaltrends in tank hydrology. Highest productivity levels are associated with periods of declining water storage, whilst the lowest levels are associated with the periods of maximum water storage shortly after the NW monsoon. This variation is primarily attributed to dilution effects associated with depth and storage area. During the yalaperiod, encroachment of the surface layer by several species of aquatic macrophyte also has progressively negative impacts on productivity. The most seasonal tanks show wider extremes in seasonal nutrient dynamics, overall, with less favourable conditions than the ‘semi-seasonal’ tanks. Never the less all the tanks can be considered as being highly productive with NP levels comparable to fertilised pond systems for much of the year. This indicates that nutrient status is not likely to be amongst the most important constraints to enhancing fish production.Other potential management improvements based on these results are discussed. [PDF contains 19 pages]
  • Potential for poverty focused integration of aquaculture into irrigation systems in Batticaloa District

    Murray, F.J. (Institute of Aquaculture, University of Stirling, 2002)
    The visit highlighted the vital contribution of the inland fisheries sector to provision of basic food security within the uncleared area (farmers report very low consumption frequencies for all other fish or meat protein substitutes). A 30-mile system of Brackish water lagoons which demarcates the cleared and uncleared areas is the main source of retailed fish in the uncleared area. Second in importance is the inland tank fishery, where the bulk of production emanatesfrom 17 major irrigation reservoirs. [PDF contains 29 pages]
  • The nature of small-scale farmer managed irrigation systems in North West Province, Sri Lanka and potential for aquaculture

    Murray, F.J.; Little, D.C. (Institute of Aquaculture, University of Stirling, 2000)
    RRAs were carried out in two Small Tank Cascade systems (STCs) of North West Province, Sri Lanka (less than 1000 ha total watershed area). A total of 21 tanks and 7 villages were investigated with primary emphasis on two upper watershed communities. The two systems differ primarily in their resource base; namely rainfall, natural forests and proximity to large scale perennial irrigation resources. [PDF contains 86 pages]
  • Inland fisheries resources and the current status of aquaculture in Sri Lanka

    Murray, F.J.; Little, D.C. (Institute of Aquaculture, University of Stirling, 2000)
    The aim of this working paper was to evaluate the potential of different fisheries enhancement and aquacultural systems to benefit marginal farmers who manage small rainfed irrigation systems in the lowland Dry zone of Sri Lanka. Analysis was based on secondary data and key informant interviews with professional fishermen and marginal farmers in N.W Province. [PDF contains 57 pages]
  • The lowland dry zone of Sri Lanka: site for study of aquaculture development within farmer-managed irrigation systems and methodology for participatory situation appraisal

    Murray, F.J.; Little, D.C. (Institute of Aquaculture, University of Stirling, 2000)
    The aims of this paper are twofold. Firstly to characterise rural poverty and to give a broad overview of the agro-ecological, climatic and socio-economic conditions in Sri Lanka which shape poverty. Secondly to present the methodology employed to screen suitable field research areas and the techniques subsequently used to carry out Rapid Rural Appraisal in two upper-watersheds villages. Also presented are details of a concurrent stakeholder analysis that aimed to investigate the capacity of secondary stakeholders to promote sustainable aquaticresource development and to invite their participation in the formulation of a participatory research agenda.[PDF contains 58 pages]
  • Assessing the sustainability of brackish water aquaculture systems in the Philippines. Working Paper 4: Aquaculture and poverty - a case study of five coastal communities in the Philippines

    Irz, X.T.; Stevenson, J.R.; Tanoy, A.; Villarante, P.; Morissens, P. (University of Reading, 2003)
    After reviewing the rather thin literature on the subject, we investigate the relationship between aquaculture and poverty based on a case study of five coastal communities in the Philippines. The analysis relies on a data set collated through a questionnaire survey of 148 households randomly selected in these five communities. The methodological approach combines the qualitative analysis ofhow this relationship is perceived by the surveyed households and a quantitative analysis of the levels and determinants of poverty and inequality in these communities. There is overwhelming evidence that aquaculture benefits the poor in important ways and that it is perceived very positively by the poor and non-poor alike. In particular, the poor derive a relatively larger share of their income from aquaculture than the rich, and a lowering of the poverty line only reinforces this result. Further, a Gini decomposition exercise shows unambiguously that aquaculture represents an inequality-reducing source of income. We believe that the pro-poor character of brackish water aquaculture in the study areas is explained by the fact that the sector provides employment to a large number of unskilled workers in communities characterized by large surpluses of labour. Our results also suggest that theanalysis of the relationship between aquaculture and poverty should not focus exclusively on the socio-economic status of the farm operator/owner, as has often been the case in the past. [PDF contains 51 pages]
  • Assessing the sustainability of brackish water aquaculture systems in the Phillipines. Working Paper 1: A typology of brackish-water pond aquaculture systems in the Philippines

    Stevenson, J.R.; Irz, X.T.; Petit, J.; Alcalde, R.-G.; Morissens, P. (University of Reading, 2003)
    Aquaculture in the Philippines is a long-standing activity but has witnessed relatively recent, rapid, technical change with the introduction of hatchery technology and commercial feed-mills changing the production possibilities for a fishpond operator. We are confronted with a diversity of aquaculture practices in the coastal areas of the Philippines, with new technologies being incorporated into more traditional systems. As a first step to understanding the sector, we therefore present a typology of farming systems with the motivation of generating domains (farm “types”) over which we can compare performance on a number of indicators. Our typology, restricted to brackish-water pond systems, is constructed using multivariate methods (principal components analysis, cluster analysis). Eight variables are used relating to the management of the farm across all the major factors of production. A stratified net sample of 136 observations provides the data for the analysis, from a farm-level survey carried out between January and June 2003 in the two main brackish-water production regions in the Philippines. We define five farm types from this analysis. In later work we will show how the use of this typology can be used for comparative study of economic, social and ecological performance at the farm-level. [PDF contains 42 pages]
  • The improved management of small-scale cage culture in Asia: final technical report

    Bulcock, P.; Beveridge, M.C.M:; Hambrey, J. (University of Stirling, Institute of Aquaculture, 2000)
    The purpose of the project is to develop sustained small-scale cage fish culture in inland and coastal watersthrough improved understanding of the social, institutional and resource environment of resource poor groups. Two Asian countries, Bangladesh (inland systems) and Vietnam(marine), were studied with this workshop bringing together both sides of the project together with representatives of collaborative institutions, government departments anduniversities. Addressing the overall aim of producing guidelines for the planning and extension of cage aquaculture in Asia a combination of group work and plenary discussion was conducted producing the following outputs. 1) An assessment of cage aquaculture potential, 2) Development options for small-scale cage culture, 3) A review of tools and methodologies and 4) Policy initiatives for sustainable cage culture development. Key issues raised were the use of outputs as a guide to be adapted to regional circumstances to facilitate farmer and extension worker discussion and not as a rigid methodology. Thedegree of linkage between development, research and government institutions was also considered a crucial factor in benefiting the research and development of cage culture at the local, regional and national level and vital in affecting the future policies by both development and government institutions. [PDF contains 242 pages]
  • Genetic improvement and utilisation of indigenous tilapia in southern Africa: final technical report, December 1st 1998 to June 31st, 2002

    Brink, D.; Mair, G.C.; Hoffman, L.; Beardmore, J.A. (University of Stellenbosch, Aquaculture Dvision, 2002)
    Mozambique tilapia (Oreochromis mossambicus) is an indigenous tilapia species in southern Africa, until now the majority of genetic research has been carried out on Asian species of tilapia but this project aims to look at this African species. Those most suited to further development in aquaculture in southern Africa have now beenidentified. The genetic characterisation of strains has been completed. This information has aided the choice of strains for use in small scale aquaculture and for genetically male tilapia (GMT) production. They will form the basis of future strategies for further genetic improvement, and management of genetic diversity of Mozambique tilapia. The information will also contribute towards responsible management and development ofgenetic resources, particularly with regard to indigenous species of tilapia. Good progress has been made with the adaptation and implementation of producing the supermale fish required to produce all male offspring, resulting in faster growing populations of tilapia. The presence of the project and its associated activity has been a catalyst for a surge in interest in tilapia culture throughout southern Africa. [PDF contains 183 pages]