The WorldFish Center, a CGIAR Consortium Research Center, is an international, non-profit research organization dedicated to reducing poverty and hunger by improving fisheries and aquaculture. CGIAR is a global research partnership that unites organizations engaged in research for sustainable development. CGIAR research is dedicated to reducing rural poverty, increasing food security, improving human health and nutrition, and ensuring more sustainable management of natural resources. Wikipedia.
Purcell S.W.,Worldfish Center |
Purcell S.W.,Southern Cross University of Australia
Marine Biology | Year: 2010
Understanding concealment behaviour of marine animals is vital for population surveys and captive-release programmes. The commercially valuable sea cucumber Holothuria scabra Jaeger 1833 (Holothuroidea) can display a diel burying cycle, but is it widely predictable? Circadian burying of captive H. scabra juveniles, and both juveniles and adults in the wild, was examined in New Caledonia. Groups of ten cultured juveniles in mesh chambers in a tank were monitored for 24 h. Small juveniles (1-5 g) displayed an expected diel cycle of epibenthic foraging in the afternoon and night then burial in sediments in the morning. Burial was related significantly to both light and temperature in combination. Similar groups of juveniles were handled once or three times a day for 1 week then frequency of emergence during another week was compared to unhandled controls. Handling stress, whether occasional or frequent, significantly suppressed the frequency of their afternoon emergence from sediments for 4 days. In a coastal seagrass bed, burial and emergence of H. scabra were monitored during days of opposing tidal cycles in three seasons. Adults seldom buried during the day except in the cool season. At that site, most small hatchery-produced H. scabra juveniles were buried during most of the day, while larger juveniles showed little diurnal burying. This study underscores that the circadian behaviours of marine animals can exhibit substantial spatial variation, may be absent at certain sites or seasons, and can be mediated by a complexity of factors that vary over short timescales. © Springer-Verlag 2009.
Barman B.K.,Worldfish Center |
Little D.C.,University of Stirling
Aquaculture | Year: 2011
Seed production of Nile tilapia (Oreochromis niloticus L.) in nylon mesh net cages (hapas) was tested through a participatory on-farm trial with households in NW Bangladesh. A total of 43 households with small ponds (0.04-0.08ha) located close to the homesteads were sampled from poor to medium social groups in three communities: Tarala Banara (TB), Dewnaghata (DW) and Dola Para (DP). Broodfish of GIFT strain Nile tilapia (12 female and 6 male; 60g size) were stocked in a single spawning hapa (3×2×1m). Swim-up fry were collected from breeding hapas at 15day intervals and stocked alternately in two nursing hapas (1.5×1×1m). With the exception of 15 households at DP in which flooding caused loss of fish, most of the households in TB and DW produced tilapia fry from hapas for 4-5months in addition to the usual production of foodfish/fingerlings in their ponds. Mean swim-up fry production in TB and DW was 5185±3764 and 3415±1536fryhousehold-1, leading to nursed fry production of 2708±1967 and 1380±734fryhousehold-1 respectively. Nursed fry were sold (70%) or re-stocked (30%) for foodfish production in the participants' own ponds. Only households with perennial ponds that were able to hold and rear tilapia broodfish (25% of total households at TB and DW) successfully produced seed in Year 2, but such households started earlier in the season (March) and achieved significantly higher productivity than the previous year. Hapa productivity was impacted by local soil type, presence of shade, depth of mud and level of drainage inputs; more fry were produced in ponds based on sandy and sandy-loam soils with less overhanging vegetation and shade, lower levels of turbidity and benthic mud, and no drainage connections with tube wells or surface run-off. Poorer households were more successful overall and tended to prioritise sale of fry over retention for foodfish culture Households engaged in ancillary fry trading and/or nursery businesses also tended to be relatively successful. Between 8 and 20 customers were supplied by each hapa operator, indicating the broader impacts of local seed production on grow-out for foodfish production. © 2011 Elsevier B.V.
Hall S.J.,Worldfish Center |
Hilborn R.,University of Washington |
Andrew N.L.,Worldfish Center |
Allison E.H.,University of East Anglia
Proceedings of the National Academy of Sciences of the United States of America | Year: 2013
This article examines two strands of discourse on wild capture fisheries; one that focuses on resource sustainability and environmental impacts, another related to food and nutrition security and human well-being. Available data and research show that, for countries most dependent on fish to meet the nutritional requirements of their population, wild capture fisheries remain the dominant supplier. Although, contrary to popular narratives, the sustainability of these fisheries is not always and everywhere in crisis, securing their sustainability is essential and requires considerable effort across a broad spectrum of fishery systems. An impediment to achieving this is that the current research and policy discourses on environmental sustainability of fisheries and food security remain only loosely and superficially linked. Overcoming this requires adoption of a broader sustainability science paradigm to help harness synergies and negotiate tradeoffs between food security, resource conservation, and macroeconomic development goals. The way society chooses to govern fisheries is, however, an ethical choice, not just a technical one, and we recommend adding an ethical dimension to sustainability science as applied to fisheries.
Beare D.,Worldfish Center |
ICES Journal of Marine Science | Year: 2012
Average towing speed by Dutch beam trawlermen has fallen substantially between 2002 and 2009. Changes in towing speed are related to changes in oil price. The price of their valuable main target species (sole, Solea vulgaris) did not influence towing speed. © 2012 International Council for the Exploration of the Sea.
Lorenzen K.,University of Florida |
Lorenzen K.,Mote Marine Laboratory |
Beveridge M.C.,Worldfish Center |
Mangel M.,University of California at Santa Cruz |
Mangel M.,University of Bergen
Biological Reviews | Year: 2012
Fish aquaculture for commodity production, fisheries enhancement and conservation is expanding rapidly, with many cultured species undergoing inadvertent or controlled domestication. Cultured fish are frequently released, accidentally and deliberately, into natural environments where they may survive well and impact on wild fish populations through ecological, genetic, and technical interactions. Impacts of fish released accidentally or for fisheries enhancement tend to be negative for the wild populations involved, particularly where wild populations are small, and/or highly adapted to local conditions, and/or declining. Captive breeding and supplementation can play a positive role in restoring threatened populations, but the biology of threatened populations and the potential of culture approaches for conserving them remain poorly understood. Approaches to the management of domestication and cultured-wild fish interactions are often ad hoc, fragmented and poorly informed by current science. We develop an integrative biological framework for understanding and managing domestication and cultured-wild fish interactions. The framework sets out how management practices in culture and for cultured fish in natural environments affect domestication processes, interactions between cultured and wild fish, and outcomes in terms of commodity production, fisheries yield, and conservation. We also develop a typology of management systems (specific combinations of management practices in culture and in natural environments) that are likely to provide positive outcomes for particular management objectives and situations. We close by setting out avenues for further research that will simultaneously improve fish domestication and management of cultured-wild fish interactions and provide key insights into fundamental biology. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.
Ziv G.,Princeton University |
Ziv G.,Stanford University |
Baran E.,Worldfish Center |
Nam S.,Inland Fisheries Research and Development Institute |
And 2 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2012
The Mekong River Basin, site of the biggest inland fishery in the world, is undergoing massive hydropower development. Planned dams will block critical fish migration routes between the river's downstream floodplains and upstream tributaries. Here we estimate fish biomass and biodiversity losses in numerous damming scenarios using a simple ecological model of fish migration. Our framework allows detailing trade-offs between dam locations, power production, and impacts on fish resources. We find that the completion of 78 dams on tributaries, which have not previously been subject to strategic analysis, would have catastrophic impacts on fish productivity and biodiversity. Our results argue for reassessment of several dams planned, and call for a new regional agreement on tributary development of the Mekong River Basin.
Cochrane K.L.,Food and Agriculture Organization of the United Nations |
Andrew N.L.,Worldfish Center |
Fish and Fisheries | Year: 2011
The social and economic importance of small-scale fisheries is frequently under-valued, and they are rarely effectively managed. There is now growing consensus on how these fisheries could be managed for sustainability and to minimize the risks of crossing undesirable thresholds. Using a concept developed in health care, these approaches have been referred to as primary fisheries management. By encouraging the use of best-available information in a precautionary way, the approaches will facilitate sustainable use and should therefore be encouraged, but they accept high scientific and implementation uncertainties as unavoidable because of limited management and enforcement resources and capacity. It is important to recognize that this limitation will result in social costs, because application of a precautionary approach in the face of high uncertainties will require forgoing potential sustainable benefits. Acceptance of primary fisheries management as a final and sufficient goal could therefore add a further constraint on the possibility of fishing communities escaping the poverty trap. Primary fisheries management should be seen as a first and minimum target for fisheries where there is currently no or inadequate management, but the longer-term goal should still be well informed and adaptive management that strives for optimal benefits, referred to here as tertiary management. © 2010 Blackwell Publishing Ltd.
Murshed-E-Jahan K.,Worldfish Center |
Pemsl D.E.,Worldfish Center
Agricultural Systems | Year: 2011
Intensification of agriculture often requires external inputs, has negative environmental effects and increases risk, especially for small-scale producers. Integrated aquaculture-agriculture (IAA) instead uses on-farm synergy effects of crop and fish production. The impact of long-term IAA training provided to small-scale farmers in Bangladesh is assessed using panel data from 260 project and 126 control farmers who were monitored from 2002/2003 to 2005/2006. We find that the training had a significant positive impact on farmers' technical efficiency, total factor productivity and net incomes. These result in higher food consumption and better nutrition for trained households compared to control farmers. © 2011 Elsevier Ltd.
Brummett R.E.,The World Bank |
Beveridge M.C.M.,Worldfish Center |
Cowx I.G.,University of Hull
Fish and Fisheries | Year: 2013
Freshwater allocation in an environment of increasing demand and declining quality and availability is a major societal challenge. While biodiversity and the needs of local communities are often in congruence, the over-riding necessity of meeting national demands for power, food and, increasingly, mitigation of the hydrological effects of climate change, often supersedes these. Sophisticated models of ecosystem function to establish environmental flows are difficult to implement and consequently have generally failed to reduce rates of biodiversity and habitat loss, resulting in disenfranchisement of local communities resulting from dam construction and water abstraction for industry and agriculture. There are no agreed standards upon which a fairer allocation of resources can be made and thus a pragmatic approach to the resolution of these conflicts is clearly needed. While having generally negative impacts on biodiversity and traditional lifestyles, creation of new infrastructure and active management generates national economic growth and much-needed employment. Intensification of usage in watersheds already expropriated for human enterprise can spare land needed for the biodiversity that will fuel adaptation for the future. Taking advantage of a range of mitigation technologies and building their cost into the investment plans for water management infrastructure can improve the cost/benefit ratio of water control infrastructure and may be a more practical and efficacious approach to the valuation of fisheries and the maintenance of other essential services from functional aquatic ecosystems. © 2012 John Wiley & Sons Ltd.
Weeratunge N.,Worldfish Center |
Snyder K.A.,Worldfish Center |
Sze C.P.,Worldfish Center
Fish and Fisheries | Year: 2010
Most research on gender difference or inequities in capture fisheries and aquaculture in Africa and the Asia-Pacific focuses on the gender division of labour. Emerging research on globalization, market changes, poverty and trends in gendered employment within this sector reveals the need to move beyond this narrow perspective. If gleaning and post-harvesting activities were enumerated, the fisheries and aquaculture sector might well turn out to be female sphere. A livelihoods approach better enables an understanding of how employment in this sector is embedded in other social, cultural, economic, political and ecological structures and processes that shape gender inequities and how these might be reduced. We focus on four thematic areas - markets and migration, capabilities and well-being, networks and identities, governance and rights - as analytical entry points. These also provide a framework to identify research gaps and generate a comparative understanding of the impact of development processes and socioecological changes, including issues of climate change, adaptation and resilience, on gendered employment. Without an adequate analysis of gender, fisheries management and development policies may have negative effects on people's livelihoods, well-being and the environment they depend on, or fail altogether to achieve intended outcomes. © 2010 Blackwell Publishing Ltd.