Aquaculture's Potential Impacts on Conservation of Wild Stocks and Biodiversity

Anderson theorizes that development of the aquaculture of a fish species (also captured in an open-access fishery) favours the conservation of its wild stocks, if competitive market conditions prevail. However, his theory is subject to significant limitations. While this is less so within his model, it is particularly so in an extended one outlined here. These other models allow for the possibility that aquaculture development can impact negatively on wild stocks thereby shifting the supply curve of the capture fishery, or raise the demand for the fish species subject both to aquaculture and capture. Such development can threaten wild fish stocks and their biodiversity. While aquaculture development could in principle have no impact on the biodiversity of wild stocks or even raise aquatic biodiversity overall, its impact in the long-term probably will be one of reducing aquatic diversity both in the wild and overall. The development of aquaculture does not automatically ensure long-term sustainability of fish and other aquatic supplies.

Poverty and aquatic resources in Vietnam: an assessment of the role and potential of aquatic resource management in poor people's livelihoods

This report seeks to discuss a variety of approaches to poverty in order to illustrate the diversity of poor people, and the range of ways in which people are poor, facilitating a broader understanding of poverty and the significance of aquatic resources in poor people’s livelihoods. This is intended to provide a balance to the general neglect of the poor in the pursuit of aquaculture development within the Fisheries sector. It is also intended that this approach to poverty will assist in the planning and targeting of aquatic resource interventions that aim to promote poverty alleviation. In its many different forms, poverty remains a persistent problem with a great number of people facing deprivation and vulnerable livelihoods. Rates of poverty alleviation also differ; whereas the Red River Delta has achieved the greatest reductions in poverty, the Mekong Delta has achieved the smallest improvements, with possible indications that inequality has increased (see 2.4). Inequality between regions persists despite progress in all regions. (PDF has 37 pages.)

Final report of the Support to Regional Aquatic Resources Management (STREAM): a NACA networking initiative

The governing council of Naca has resolved to effect a shift in emphasis from aquaculture development to aquaculture for development. This will require engaging partners from a broad spectrum of government and development agencies, the nature of the information that will need to be gathered and the strategies used for disseminating information and initiating action. The vehicle for operationalising this shift is STREAM - Support to Regional Aquatic Resources Management. This report outlines the nature of the STREAM network, its relationship to NACA's vision, mission, objectives and operating principles, and how STREAM differs from previous NACA's networks. Because STREAM is different, a theoretical basis for network communication is presented along with an outline of the preliminary steps in getting the network up and running. (Pdf contains 33 pages).

Enhancement of fish production in Borno State with extension services

Borno State possesses great potentials for fish production both from inland fisheries and aquaculture. The socio-economic and environmental production factors are suitable for fish production. If the potential of the State were well harnessed, it would be playing significant roles in achieving self-sufficiency in fish production in Nigeria. But the situation at the moment is that its fisheries potentials are not being optimally utilized. While the inland waters of Lake Chad are currently being recklessly exploited, aquaculture development is given little or no attention. It is evident that there is a missing link between research results and the potential end users. Because information in fish production variables is a pre-requisite for fisheries development, the gap that exists between two poles must be bridged, fisheries Extension provides this important link between research result and the end users of research findings. The paper examines the importance of extension services as the key to unlock fish production information that are usually consigned to the pages of academic journals and research publications

Food and nutrition security in Timor-Leste

This report is a literature review on Food and Nutrition Security in Timor-Leste based on data from surveys conducted by the Timor-Leste National Statistics Directorate, as well as from national and international organizations working in Timor-Leste. This review was supported by the Australian Centre for International Agricultural Research (ACIAR)-funded project “Strategy for Investment in Fisheries in East Timor”. This report describes the current food and nutrition situation in Timor-Leste for the purpose of planning and implementing interventions aimed at improving food and nutrition security, especially within aquatic agricultural systems. The potential role of aquaculture in improving food and nutrition security is considered, with reference to the recently endorsed Timor-Leste National Aquaculture Development Strategy (2012-2030) developed by the National Directorate of Fisheries and Agriculture, Ministry of Agriculture and Fisheries.

Comparative effect of Pediococcus acidilactici and Lactococcus lactis on growth performance, survival and enzyme activity of western white leg shrimp (Litopenaeus vannamei)

This study was done in Shahid Kiani Marine Aquaculture Development Center, Choebde, Abadan in order to evaluate the effects of Pediiococcus acidilactici, Lactococcus lactis and vitamin C on growth performance, survival, enzymatic activities and immune responses of L. vannamei during three months. Treatments were included control group, Pediiococcus and Lactococcus treatments which fed with diet containing 1×10P9P cfu gP_1P bacteria and vitamin C. At the end of the experiment, the growth factors, immune parameters, digestive enzymes, intestinal, histology of intestine, carcasses and microbial flora (bacterial total count and lactic acid count) were evaluated. The results indicated that administration of lactobacillus had significant effects on the growth factors as the highest weight, increase specific growth rate, relative growth rate, feed conversion ratio and protein efficiency in the shrimps received pediococcus and then Lactococcus (P<0.05). The best immune function was also observed in the shrimps fed by probiotics, so that proteins and hemoglobin̛ hemolymph, phenoloxidase activity and challenged with V. parahaemolyticus showed a statistical difference comparing to the control group and the group received vitamin C (P<0.05). Some digestive enzymes, in pediococcus treatment showed a significant increase when compared to other treatments (P<0.05). Significant changes in bacterial intestinal flora were observed in probiotic groups compared with control and vitamin C groups (P < 0.05). Histological results showed the positive effects of probiotics in the gut (P < 0.05). While these supplements cannot caused to significant impacts on the shrimp carcass composition (P ˃ 0.05). As a result pediococcus group had the best performance among treatments.

Quantitative pathways for Northeast Atlantic fisheries based on climate, ecological–economic and governance modelling scenarios

Here we present quantitative projections of potential futures for ecosystems in the North Atlantic basin generated from coupling a climate change-driven biophysical model (representing ecosystem and fish populations under climate change) and a scenario-driven ecological–economic model (representing fleets and industries under economic globalization). Four contrasting scenarios (Baseline, Fortress, Global Commons, Free Trade) were defined from the perspective of alternative regional management and governance of the oceanic basin, providing pathways for the future of ecosystems in the Northeast Atlantic basin by 2040. Results indicate that in the time frame considered: (1) the effects of governance and trade decisions are more significant in determining outcomes than the effects of climate change alone, (2) climate change is likely to result in a poleward latitudinal shift of species ranges and thus resources, with implications for exploitation patterns, (3) the level of fisheries regulation is the most important factor in determining the long term evolution of the fisheries system, (4) coupling climate change and governance impacts demonstrates the complex interaction between different components of this social–ecological system, (5) an important driver of change for the future of the North Atlantic and the European fishing fleets appears to be the interplay between wild fisheries and aquaculture development, and finally (6) scenarios demonstrate that the viability and profit of fisheries industries is highly volatile. This study highlights the need to explore basin-scale policy that combines medium to long-term environmental and socio-economic considerations, and the importance of defining alternative sustainable pathways.

A marine candida sake as source of immunostimulants to fenneropenaeus indicus

Aquaculture has developed rapidly over the last three decades to become an important activity worldwide.The Food and Agricultural Organization (FAO) of the UN acknowledge that global fishery output must be increased by at least 50% to offset projected shortfalls in dietary protein by 2030.LAquaculture has developed rapidly over the last three decades and has become an importat industry as today’s demand for fish exceeds the natural supply.lmmunostimulants are chemical compounds that activate the immune system of animals and render them more resistant to infections by viruses, bacteria, fungi, and parasites. lmmunostimulants have been obtained from diverse natural sources where, microbial cell wall acts as the main source.The salient findings of the study are summariseSeven marine yeasts were screened for growth promoting and immunostimulant property in F. indicus. Candida sake S165 was found to be best in terms of its support for growth and protection against white spot virus infection.The study revealed that marine yeast Candida sake can be effectively used as potential source of immunostimulants for application in penaeid prawns culture systems. The study emphasise the fact that the dose and frequency of application of immunostimulants are to be standardised and validated before commercialisation to achieve optimum stimulation of the immune system and to avoid immune fatigue die to verdose.Marine yeast (whole cell) was found to support better immunostimulation compared to its cell wall component B-1,3-glucan. This study shows that administration of marine yeast (whole cell) or B-1,3-glucan as immunostimulants in aquaculture would definitely help in protection of the stock to a few more days even though total protection is not being imparted. This partial protection itself would be highly helpful to the farming industry so that they can get sufficient time to plan for a safe harvest and save the crop from cent percent mortality.

Use of geographical information systems as a tool for predicting fish yield in tropical reservoirs : case study on Sri Lankan reservoirs

Use of geographical information systems (GIS) in inland fisheries has hitherto been essentially restricted to site evaluation for aquaculture development and assessment of limnological changes in time and space in individual water bodies. The present GIS study was conducted on the land-use pattern of the catchments of nine reservoirs in Sri Lanka, for which detailed fishery data, viz. yield, fishing intensity, landing size of major constituent species, together with selected limnological data such as conductivity and chlorophyll-a, were available. Potential statistical relationships (linear, curvilinear, exponential and second-order polynomial) of fish yield (FY, in kg ha−1 yr−1) to different land-use patterns, such as forest cover (FC, in km2) and shrub-land (SL, in km2), either singly, or in combination, and/or the ratio of each land type to reservoir area (RA in km2) and reservoir capacity (RC in km3), were explored. Highly significant relationships were evident between FY to the ratio of SL and/or FC+SL to RA and/or RC. Similarly, the above land-use types to RA and RC ratios were significantly related to limnological features of the reservoirs. The relationships of FY to various parameters obtained in this study were much better correlated than those relationships of FY to limnological and biological parameters used in yield prediction in tropical and temperate lacustrine waters previously.

A review of stock enhancement practices in the inland water fisheries of Asia

Inland fisheries contribute only about ten percent to global fish production. Asia is the leading producer of inland fish, accounting for over 80 percent of the total production. Until recently, the inland fisheries sector had taken back stage in fisheries development plans, particularly so, given the emphasis being placed on aquaculture development throughout the world, including Asia. This report evaluates the inland fishery practices in a number of Asian countries according to habitat type, role in overall foodfish supplies and development trends. Special emphasis is laid on stock enhancement in inland fisheries in Asia, and only those fisheries in which some form of stock enhancement is practised are considered in this report.

In Asia, inland fisheries are mostly rural, artisanal activities catering to rural populations and providing an affordable source of animal protein, employment and household income. Stock enhancement is an integral component of many inland fisheries. With recent developments in
artificial propagation techniques for fast-growing and desirable fish species and the consequent increased availability of seed stock, such activities are beginning to affect inland fishery production in most Asian countries. Indeed, new avenues of production such as culture-based fisheries are increasingly adopted and seen as a way forward in most countries. Inland fishery activities also have a distinct advantage in that their development is usually less resource intensive than is aquaculture.

The economic viability of stock enhancement of large lacustrine waterbodies and rivers has not been demonstrated in any of the Asian countries, the fisheries of such waterbodies being dependent on naturally recruited stocks. The most successful stock enhancements in Asia are in floodplain beels and oxbow lakes in Bangladesh where the use of small waterbodies that are not capable of supporting natural fisheries has led to culture-based fisheries having stock and recapture rates that are very high. Culture-based fisheries are not resource intensive and are community-based activities. However, their success requires major institutional changes, and these are affected by national and local governments. In general, they can be considered to have the greatest potential for further development.

A major concern related to stock enhancements in inland waters is their possible effects on biodiversity. This is for two reasons: firstly, most countries depend wholly or partially on exotic species for stock enhancement and secondly, freshwater fishes are known to be among the most threatened of vertebrates. Major studies should be undertaken to evaluate the current situation so that remedial steps can be taken, if needed, without causing serious harm to some of the stock enhancement practices that are gaining momentum.

Patterns of use and exchange of genetic resources of the striped catfish Pangasianodon hypophthalmus (Sauvage 1878)

The present paper reviews the use and exchange of genetic resources of the migratory freshwater fish Pangasianodon hypophthalmus (Sauvage 1878) (the striped or sutchi catfish). This species is naturally distributed in the Mekong River and Chao Phraya River basins, and is cultured in several countries, but current production occurs predominantly in the Mekong Delta, Vietnam. Catfish aquaculture in Vietnam has evolved from extensive systems using wild-caught seed to an intensified farming system that is entirely dependent on hatchery-produced seed. Genetic improvement programmes on catfish have started in Vietnam, but are still in their infancy. Genetic studies have revealed several subpopulations of the species. Apart from selective breeding and the production of hybrids with closely related species, no other technologies have been applied to improve the performance of catfish. The use and exchange of P. hypophthalmus genetic resources have brought benefits to rural communities. Aquaculture development of catfish has evolved from being seen as an exploitation of natural resources to an activity that can reduce pressure on wild fish populations. Management of aquaculture stocks need to be rationalised to minimise the potential impacts it might cause to wild populations.

Qualidade higiênico-sanitária e ocorrência de Aeromonas sp. e Escherichia coli em tilápias comercializadas no varejo

Pós-graduação em Aquicultura - FCAV