Now showing items 1-7 of 7

    • Article

      Approaches to stock enhancement in mangrove-associated crab fisheries 

      L Le Vay, MJHL Lebata, M Walton, JH Primavera, ET Quinitio, CR Lavilla, FD Parado-Estepa, E Rodriguez, VN Ut, TT Nghia, P Sorgeloos & M Wille - Reviews in Fisheries Science, 2008 - Taylor & Francis
      Over the last decade, hatchery production of mud crabs has become technically and economically more feasible, enabling evaluation of the potential effectiveness of hatchery release in fisheries enhancement. The high growth rates and limited movement of released crabs means that fisheries’ yields an isolated mangrove systems with restricted recruitment can be enhanced with a few months. Thus, a release program may be an effective strategy for short-term enhancement in carefully selected specific areas. To date, results are very promising; with recovery rates up to 50% and increases in fisheries’ yield up to 46% over baseline catches. In contrast, mark-recapture studies in more open mangrove system populations shows that recruitment success and subsequent stock abundance may be largely determined by habitat availability. For these populations, restoration of lost o degraded mangrove areas has been show to be effective in promoting stock recovery through natural recruitment, with replanted mangroves supporting fisheries of equivalent economic value to that of natural mangroves, though it may take some years to reach these levels. Thus, a balanced approach to stock management could integrate both hatchery-release and habitat restoration programs, depending on local conditions and over different thin scales, with parallel-co-management to support effectiveness.
    • Article

      Culture of Artemia on rice bran: The conversion of a waste-product into highly nutritive animal protein 

      The age-old problem of finding a cheap suitable food for Artemia is finally solved with rice bran, in fact a waste-product which is available at a very low price in many countries all over the world.
    • Article

      Improved larval survival at metamorphosis of Asian seabass (Lates calcarifer) using ω3-HUFA-enriched live food 

      P Dhert, P Lavens, M Duray & P Sorgeloos - Aquaculture, 1990 - Elsevier
      Asian seabass (Lates calcarifer) larvae were fed Brachionus cultured on Chlorella and, as soon as ingestin was possible, different types of Artemia, i.e., nauplii of the San Francisco Bay (SFB) strain, Great Salt Lake (GSL) strain or GSL nauplii that had been bioencapsulated with an emulsion containing high levels of the ω3-HUFAs (highly unsaturated fatty acids) 20:5 and 22:6. San Francisco Bay Artemia with a good natural fatty acid profile and small body size could be offered earlier than the larger but HUFA-poor Great Salt Lake strain. The poor nutritional quality of the latter, however, could be corrected by enriching the nauplii with an ω3-HUFA emulsion for 24 h, after which time high levels of the ω3-HUFAs 20:5 and 22:6 were obtained. When the Artemia diet offered before metamorphosis included natural or supplemented essential fatty acids, no significant differences in dry weight, length or survival of the fish were noticed, as compared to fish fed the naturally deficient GSL Artemia. Onset of metamorphosis and physiological condition after metamorphosis, however, were influenced by the HUFA content of the ingested prey. Seabass larvae fed SFB or enriched GSL Artemia started metamorphosis on day 19, while those in the non-enriched series never achieved metamorphosis and died of a nutritional deficiency syndrome by day 27. An indication of the physiological condition of the larvae and the early detection of the syndrome was possible by subjecting 21- and 25-day-old larvae to a stress test: abrupt exposure of the larvae to 65-ppt saline water resulted in abundant and early mortality in HUFA-deficient fish larvae. Fry receiving ω3-HUFA-fortified Artemia had a superior physiological condition which was reflected by significantly lower mortality figures in the stress test.
    • Article

      Poly-beta-hydroxybutyrate-enriched Artemia sp. for giant tiger prawn Penaeus monodon larviculture 

      G Ludevese-Pascual, JLQ Laranja, EC Amar, P Sorgeloos, P Bossier & P De Schryver - Aquaculture Nutrition, 2017 - John Wiley and Sons
      The beneficial effects of PHB as supplement for giant tiger prawn Penaeus monodon postlarvae using a short-term enrichment strategy via Artemia were examined. The effects of co-supplementing with a lipid emulsion were also evaluated to determine whether it yielded an additional benefit. Results on the average weight and larval development were not significantly different among postlarvae fed the different dietary treatments, indicating that PHB supplementation could not be used to stimulate growth in P. monodon postlarvae while such positive results have been reported in other aquaculture species. Nonetheless, significantly higher survival was obtained in postlarvae fed PHB-enriched Artemia irrespective of lipid enrichment. In addition, PHB increased the survival of the postlarvae after exposure to a lethal dose of ammonia. Lipid supplementation nullified this effect. The cumulative mortality of postlarvae subjected to a sublethal concentration of ammonia for 24 h and subsequent exposure to pathogenic Vibrio campbelli showed that PHB but not lipids could effectively enhance the resistance of the postlarvae. Co-supplementing lipids even significantly decreased this outcome. Our study indicates that PHB supplementation increases the quality of larval P. monodon and their chance of surviving under adverse environmental conditions. The short-term co-supplementation with lipid emulsion did not add to these effects.
    • Article

      Poly-β-hydroxybutyrate (PHB) accumulating Bacillus spp. improve the survival, growth and robustness of Penaeus monodon (Fabricius, 1798) postlarvae 

      JLQ Laranja, GL Ludevese-Pascual, EC Amar, P Sorgeloos, P Bossier & P De Schryver - Veterinary Microbiology, 2014 - Elsevier
      Low larval survival resulting from suboptimal culture conditions and luminous vibriosis poses a major problem for the larviculture of penaeid shrimp. In this study, a poly-β-hydroxybutyrate (PHB) accumulating mixed bacterial culture (mBC; 48.5% PHB on cell dry weight) and two PHB accumulating bacterial isolates, Bacillus sp. JL47 (54.7% PHB on cell dry weight) and Bacillus sp. JL1 (45.5% PHB on cell dry weight), were obtained from a Philippine shrimp culture pond and investigated for their capacity to improve growth, survival and robustness of Penaeus monodon postlarvae (PL). Shrimp PL1 and shrimp PL30 were provided with the PHB containing bacterial cultures in the feed for 30 days followed by, respectively, a challenge with pathogenic Vibrio campbellii and exposure to a lethal dose of ammonia. Prior to the pathogenic challenge or ammonia stress, growth and survival were higher for shrimp receiving the PHB accumulating bacteria as compared to shrimp receiving diets without bacterial additions. After exposure to the pathogenic challenge the shrimp fed PHB accumulating bacteria showed a higher survival as compared to non-treated shrimp, suggesting an increase in robustness for the shrimp. Similar effects were observed when shrimp PL30 were provided with the PHB accumulating bacterial cultures during a challenge with pathogenic V. campbellii through the water. The survival of shrimp exposed to lethal ammonia stress showed no significant difference between PHB accumulating bacteria-fed shrimp and non-PHB treated shrimp. The data illustrate that bacilli capable of accumulating PHB can provide beneficial effects to P. monodon post-larvae during culture in terms of growth performance, survival and resistance against pathogenic infection and ammonia stress. Further investigations are required to verify the PHB effect of the bacterial cultures on the shrimp.
    • Conference paper

      Sustaining aquaculture by developing human capacity and enhancing opportunities for women 

      MJ Williams, R Agbayani, R Bhujel, MG Bondad-Reantaso, C Brugère, PS Choo, J Dhont, A Galmiche-Tejeda, K Ghulam, K Kusakabe, D Little, MC Nandeesha, P Sorgeloos, N Weeratunge, S Williams & P Xu - In RP Subasinghe, JR Arthur, DM Bartley, SS De Silva, M Halwart, N Hishamunda, CV Mohan & P Sorgeloos (Eds.), Farming the Waters for People and Food. Proceedings of the Global Conference on Aquaculture 2010, Phuket, Thailand, 22-25 September 2010, 2012 - FAO; NACA
      People are at the heart of sustaining aquaculture. Development of human capacity and gender, therefore, is an important human dimension. Human capacity development (HCD) was a major thrust of the 2000 Bangkok Declaration and Strategy, but gender was not addressed. The Food and Agriculture Organization of the United Nation's (FAO) Strategic Framework for Human Capacity Development (HCD) emphasized building human capacity in a coherent fashion at four levels - in individuals, organizations, sectors/networks and in the overall enabling environment. Although strategic HCD in aquaculture has not received attention, substantial HCD has occurred in aquaculture education and training. Aquaculture departments in universities, aquaculture research institutes, networks and professional societies all include training as central activities.

      Women are active participants in aquaculture supply chains, but a dearth of gender-disaggregated information hampers accurate understanding of their contribution. Research results and FAO National Aquaculture Sector Overview (NASO) fact sheets show that female participation rates vary by type and scale of enterprise and country. Women are frequently active in hatcheries and dominate fish processing plant labourers. Women's work in small-scale aquaculture frequently is unrecognized, under or unpaid. Most aquaculture development projects are not gender sensitive, and aquaculture success stories often do not report gender dimensions; projects can fail if their designs do not include gender.

      Lacking gender-disaggregated data on participation rates and trends in education, we conducted a preliminary survey of aquaculture tertiary institutes in Africa, Asia, Europe and North America. The percentage of female graduates in aquaculture increased considerably over the last four decades, from zero or low numbers in the 1970s to recent rates of around 30-60 percent; rates vary both by country and within countries. No data are available to track whether female graduates are entering successful careers in aquaculture. To accelerate HCD to meet the needs of aquaculture growth, commodity and theme priorities for HCD must be established. Educational institutions should cooperate and harmonize work programmes and overcome language barriers. Aquaculture education needs the best students and should help prepare them for rewarding careers. More social science content is needed in aquaculture curricula to groom graduates for management and leadership roles. The gender balance in aquaculture faculty could be improved by recruiting and retaining more women.

      Gender should be put firmly on the policy agenda and built into normative instruments, old and new, complemented by the collection of gender-disaggregated data for aquaculture supply chains. Women should be empowered through gender equity in access to financial, natural, training and market resources. Women in aquaculture should not be stereotyped as 'small-scale' and poor. Women are often hampered by systemic barriers such as lack of legal rights. Women should be encouraged to build their management, leadership and entrepreneural skills. In circumstances where rural men have migrated for work, small-scale aquaculture has proven a suitable livelihood option to reduce the pressure on women. Because postharvest processing and fish trade are feminized occupations, gender equity deserves special attention in fair trade and fish certification schemes. HCD and gender are receiving more attention in rehabilitation efforts to assist survivors from disease and natural disasters.
    • Article

      Use of ongrown Artemia in nursery culturing of the tiger shrimp 

      P Dhert, RF Bombeo & P Sorgeloos - Aquaculture International, 1993 - Springer Verlag
      Juvenile and adult Artemia produced in a semi flow-through culture system were used as food for postlarval shrimp. The growth performance of shrimp reared on such ongrown Artemia live prey is identical to the growth obtained when feeding newly hatched Artemia. However, a significantly better stress resistance is obtained when the postlarvae are exposed to a low salinity in a stress test. Besides nutritional and energetic advantages, the use of Artemia biomass for feeding postlarval shrimp also results in improved economics as expenses for cysts and weaning diets can be reduced.