Now showing items 627-646 of 1064

    • Article

      The macronutrient composition of natural food organisms mass cultured as larval feed for fish and prawns 

      OM Millamena, VD Peñaflorida & PF Subosa - The Israeli Journal of Aquaculture-Bamidgeh, 1990 - Society of Israeli Aquaculture and Marine Biotechnology
      The macronutrient composition of natural food organisms that are mass cultured as feed for the larval stages of fish and prawns in the SEAFDEC Aquaculture Department was determined by chemical analysis. The food organisms included five species of marine phytoplanktons (algae): Chaetoceros calcitrans, Skeletonema costatum, Tetraselmis chui, Chlorella vulgaris and Isochrysis galbana, and two zooplanktons: Artemia sp. nauplii (San Francisco Bay strain) and Brachionus plicatilis. The algal species were grown in batches on Guillard and Ryther media and harvested during the exponential phase of growth using a procedure which preserved cellular integrity and prevented cell lysis. The zooplankton were cultured using standard techniques adopted at the SEAFDEC Larval Food Laboratory. Each species was analyzed for proximate composition (protein, fat, fiber and ash) and for mineral content (calcium and phosphorous). Nitrogen-free extract (NFE) was determined by difference. For the five algal species, the protein, fat and NFE contents varied from 22% to 48%, 2% to 16% and 14% to 24%, respectively. The zooplanktons had higher protein and fat contents than any of the phytoplankton species except I. galbana which had the highest fat content. On the other hand, the phytoplanktons, particularly the diatoms which have a siliceous cell wall, contained significantly higher quantities of inorganic matter (ash). C. vulgaris had the highest fiber content which may be attributed to its cellulosic cell wall.
    • Article

      Major viral and bacterial disease problems in shrimp culture 

      CR Lavilla-Pitogo - Aquaculture Engineering (Philippines), 1998 - Society of Aquaculture Engineers of the Philippines
      Major disease problems particularly viral and bacterial in origin have resulted in significant decline in the production of farmed shrimps worldwide.

      The major diseases of viral and bacterial origins are listed and described. Innovations being applied to prevent and/or minimize their effects are enumerated.

      The paper suggests a broad outlook of shrimp disease by considering not only the etiological causes but also the epidemiological approach. Attempts to produce disease-free fry are still expensive and cannot be applied widely in commercial farms. The aim is to attain sustainable shrimp farming.
    • Article

      Management of brackishwater pond for milkfish fingerling production in Sri Lanka 

      DD Baliao - Journal of Inland Fisheries, 1982 - Ministry of Fisheries and Aquatic Resources
      The author reviews the present methods of milkfish (Chanos chanos) fry collection and presents his observations and recommendations of improvement.
    • Article

      Managing excess capacity in small-scale fisheries: Perspectives from stakeholders in three Southeast Asian countries 

      ND Salayo, L Garces, M Pido, K Viswanathan, R Pomeroy, M Ahmed, I Siason, K Seng & A Masae - Marine Policy, 2008 - Elsevier
      The management of fishing capacity--in both inland and marine fisheries--is a major policy concern in most countries in Southeast Asia. Excess capacity leads to a number of negative impacts, such as resource use conflicts, overfishing, environmental degradation, economic wastage, and security threats. This paper presents the results of a regional study that examined various approaches to managing excess fishing capacity in small-scale fisheries in Southeast Asia. More specifically, the paper presents an analysis of perceptions of stakeholders in Cambodia, Philippines and Thailand regarding preferred solutions to addressing excess capacity. The paper concludes with a discussion of policy guidance for addressing excess fishing capacity based on the stakeholder-preferred solutions.
    • Article

      Managing fisheries conflicts through communication planning: Experience from inland fisheries of Bangladesh 

      K Murshed-e-Jahan, ND Salayo & U Kanagaratnam - Fisheries Research, 2009 - Elsevier
      Increasing population, ineffective management, competition among fishing gears over access to resources and proliferation of destructive practices are imposing severe stress on the inland water bodies of Bangladesh. These factors also contribute to the increasing incidence of conflicts among fishery stakeholders. When unabated, these conflicts are potential threats to the livelihoods of millions of the poorest fishing communities that depend on these resources. Effective communication between conflicting parties is perceived as a key for establishing successful negotiations for managing conflicts. On this premise, this paper presents and assesses a Fisheries Conflicts Communication Framework, henceforth called FishCom, a tool for developing plans and strategies for managing fisheries conflicts in the inland fisheries of Bangladesh. This tool embodies a structured participatory process intended for use by policy-makers and conflict management practitioners. They have important roles in catalyzing and effecting changes that are instrumental in minimizing, if not totally eliminating conflicts. Experiences from applying FishCom in the inland fisheries study sites in Bangladesh show that it has enabled a systematic stakeholder-inclusive identification and evaluation of fisheries conflicts and planning of communication interventions to manage them.
    • Article

      Mangroves and brackishwater pond culture in the Philippines 

      JH Primavera - Hydrobiologia, 1995 - Springer Verlag
      Around 50% of mangrove loss in the Philippines can be traced to brackishwater pond construction. The decrease in mangroves from 450 000 ha in 1920 to 132 500 ha in 1990 has been accompanied by expansion of culture ponds to 223 000 ha in 1990. The history of fishpond development in the country includes a government-sponsored fishpond boom in the 1950-g and 1960s, the proconservation decade of the 1970s followed by a shrimp fever in the 1980s. Production from brackisshwater ponds has increased from 15 900 mt worth P7.6 million in 1938 to 267 000 mt valued at P6.5 billion in 1990. On the other hand, the maximum valuation of over $11 000 ha−1 yr−1 for unmanaged and managed mangrove forests makes them economically on par with the most profitable pond farming systems. The loss of mangrove systems and their varied goods and services is the single most important consequence of brackishwater pond culture in the Philippines. Moreover, intensive shrimp farming is associated with other ecological and socioeconomic effects such as pollution of coastal waters and decline in domestic food crops. New legislation and enforcement of existing laws, conservation of remaining mangroves, massive rehabilitation of denuded mangrove areas, and promotion of sustainable aquaculture and fisheries are recommended.
    • Article

      Mangroves and shrimp pond culture effluents in Aklan, Panay Is., central Philippines 

      JH Primavera, JP Altamirano, MJHL Lebata, AA delos Reyes Jr. & CL Pitogo - Bulletin of Marine Science, 2007 - University of Miami, Rosenstiel School of Marine and Atmospheric Science
      The capacity of a natural mangrove system in Ibajay, Aklan province, central Philippines to process shrimp pond culture effluents was assessed through analysis of mangrove community structure and 24-hr monitoring of water quality parameters (NH3-N, NO3-N, PO4-P, sulfide, and total suspended solids). Results from the latter showed decreased nutrient levels within 6 hrs after daytime draining of effluents into the mangrove stand, but only nitrate reduction was statistically significant. Based on nitrate loss, volume of water drained, mangrove area, and shrimp farming data (e.g., N loss from ponds, feed composition, feeding rate), calculations show that 1.8–5.4 ha of mangroves are required to remove nitrate wastes from 1 ha of shrimp pond. N uptake by the mangrove macroflora was supported by data showing longer nipa palm leaflets and faster mangrove seedling growth in the experimental mangrove receiving effluents compared to a control mangrove, but not from mangrove biomass measurements. These results have significant implications for the Philippine brackishwater pond culture industry to conserve or rehabilitate mangroves as potential pond biofilters, to implement legally mandated 20- and 50-m greenbelts, and to reverse the national 0.5 ha mangrove: 1.0 ha pond ratio.
    • Article

      Mangroves as nurseries: Shrimp populations in mangrove and non-mangrove habitats 

      JH Primavera - Estuarine, Coastal and Shelf Science, 1998 - Elsevier
      A total of 4845 penaeids belonging to nine species—Metapenaeus anchistus, M. ensis, M. moyebi, M. philippinensis, Penaeus merguiensis, P. monodon, P. semisulcatus, P. latisulcatus and Metapenaeopsis palmensis—were collected by pocket seine monthly over 13 months from mangrove and non-mangrove sites in Guimaras, Philippines. The restricted distribution of the three dominant species—M. ensisandP. merguiensisto the brackish water riverine mangrove, andM. anchistusto the high-salinity island mangrove and tidal flat—is probably related to different salinity and substrate preferences. Abundance and size composition of the major species suggest a strong nursery role for the riverine mangrove (high juvenile densities, relatively small sizes year-round), limited nursery use of the island mangrove (fewer shrimps, larger size ranges, presence of maturing females) and a non-nursery use (e.g. foraging) in the tidal flat. Penaeid recruitment to the river had two peaks in November and May when the average salinity was ∼20 (Practical Salinity Scale) and water temperatures were high (30–31 °C). The spatio-temporal pattern of penaeid species in Guimaras shows partitioning across habitats and seasonal recruitment influenced by physical and biological factors.
    • Article

      Mangroves, fishponds, and the quest for sustainability 

      JH Primavera - Science, 2005 - American Association for the Advancement of Science
      Aquaculture, the farming of shrimp and other useful aquatic and marine plants and animals in artificially confined and tended ponds, pens, and cages, ranks as a phenomenal success story in global food production. In 1975, aquaculture contributed 8% to the overall yield of the world's fish harvest; now it provides more than one-third of the yield. Total aquaculture production in 2003 was 54.8 million metric tons valued at $67.3 billion in U.S. dollars. More than 90% of this output comes from Asia, where aquaculture has its origins and where this month's essay author has lived and worked all of her life. In her essay, Jurgenne H. Primavera, senior scientist of the Aquaculture Department of the Southeast Asian Fisheries Development Center based in Iloilo, Central Philippines, traces the recent history of aquaculture and the socioeconomic and environmental challenges that its rapid growth has wrought, especially for the mangrove ecosystems in which much of brackishwater pond aquaculture occurs. With an eye on all stakeholders, Primavera lays out how aquaculture is now falling short of the goal of sustainability and what steps might be taken to move the industry in that direction.
    • Article

      Mariculture development and livelihood diversification in the Philippines 

      ND Salayo, ML Perez, LR Garces & MD Pido - Marine Policy, 2012 - Elsevier
      This paper aims to evaluate mariculture as sustainable livelihood diversification option for coastal fishers in the Philippines and guide policy development in this direction. Mariculture in the Philippines refers to the culture of finfishes, shellfish, seaweeds and other commodities in cages, pens, stakes and rafts in marine environment. This paper evaluates the biophysical and socioeconomic contexts in which mariculture operate. Ten years after launching the first mariculture park organized and managed by the country's government fishery agency, and the nationwide promotion of this program, only 273 ha or 0.54% of the 50,150 ha total area planned for development has been established. Mariculture has not met its expected results due to a number of problems. This paper revisits the policies, organization, governance and administration of mariculture parks in the country. It also discusses the issues and challenges with mariculture as a livelihood diversification option within the context of ecosystems approach to fisheries management in the Philippines.
    • Article

      Marine leech (Zeylanicobdella arugamensis) infestation in cultured orange-spotted grouper, Epinephelus coioides 

      ER Cruz-Lacierda, JD Toledo, JD Tan-Fermin & EM Burreson - Aquaculture, 2000 - Elsevier
      Heavy infestation of a marine leech occurred among tank-reared juvenile and adult orange-spotted grouper, Epinephelus coioides Hamilton, at SEAFDEC AQD, Philippines with a prevalence of 83% and 17%, respectively. The leeches were attached in large numbers on the fins, lower jaw, under the operculum, eyes, and inside the mouth of the fish. The attachment and feeding sites exhibited frayed fins, hemorrhages and swelling of the host's skin. External and internal features indicate that the leech is Zeylanicobdella arugamensis De Silva (Hirudinea, Piscicolidae). The parasite can be effectively controlled using 50 ppm formalin bath treatment for 1 h.
    • Article

      Market survey of snappers (Genus Lutjanus) from Panay and Palawan waters 

      RMT Cheong, WG Gallardo & JD Toledo - Philippine Journal of Science, 1992 - Science and Technology Information Institute
      Thirteen species of snappers (genus Lutjanus) were identified and sourced for location of capture from surveys conducted at the Iloilo Fishing Port and Central Market. They were Lutjanus argentimaculatus,Lutjanus boutton, Lutjanus carponotatus, Lutjanus decussatus, Lutjanus fulviflamma, Lutjanus malabaricus, Lutjanus monostigma, Lutjanus quinquelineatus, Lutjanus rivulatus and Lutjanus vitta. Incidence of lutjanids was year round with a peak in May. Most abundant and commonly observed were Lutjanus vitta, Lutjanus gibbue and Lutjanus argentimaculatus.
    • Article

      Mass mortalities associated with viral nervous necrosis in hatchery-reared sea bass Lates calcarifer in the Philippines 

      Y Maeno, LD de la Peña & ER Cruz-Lacierda - Japan Agricultural Research Quarterly, 2004 - Ministry of Tropical Agricultural Research Centre
      Viral nervous necrosis (VNN), also known as viral encephalopathy and retinopathy (VER), is an emerging disease affecting larvae and juveniles of many farmed marine fish species in Asia, Australia, Europe and North America. Mass mortality occurred in 14-day old larval sea bass Lates calcarifer at a hatchery in the Philippines associated with clinical signs such as abnormal swimming behavior and pale-gray discoloration of the body. Histological investigations in moribund fish revealed marked vacuolation in the retina and brain. Cytopathic effects (CPE) were observed in SSN-1 cells inoculated with the tissue filtrate of affected sea bass. A piscine nodavirus, the causative agent of VNN, was detected in the affected tissues and SSN-1 cells inoculated with the tissue filtrate of affected fish by RT-PCR. Electron microscopy revealed non-enveloped viral particles, 22-28 nm in diameter, in the cytoplasm of the brain and retina of affected fish and in the cytoplasm of VNN-infected SSN-1 cells after CPE appeared. These results indicate that mass mortality of sea bass larvae in the Philippines was caused by a piscine nodavirus.
    • Article

      Mass mortality of hatchery-reared milkfish (Chanos chanos) and mangrove red snapper (Lutjanus argentimaculatus) caused by Amyloodinium ocellatum (Dinoflagellida) 

      ER Cruz-Lacierda, Y Maeno, AJT Pineda & VE Matey - Aquaculture, 2004 - Elsevier
      Outbreaks of heavy infestation by the parasitic dinoflagellate Amyloodinium ocellatum in hatchery-reared milkfish (Chanos chanos) and mangrove red snapper (Lutjanus argentimaculatus) caused 100% mortality events in hatcheries in the Philippines. Parasites were recorded on the body surface in 14-day-old milkfish fry and on both skin and gills in 2-month-old snapper. Trophonts of A. ocellatum caused local erosions of fish skin and degeneration of epithelial cells at the sites of the parasite's attachment to the body surface. Separation and hyperplasia of gill epithelium and fusion of secondary lamellae at the distal parts of the gill filaments were common. High pathogenicity of A. ocellatum to fish may be attributed to the severe alterations of the fish gills, the disruption of the host's skin, and feeding of trophonts on hosts' epithelial cells. In-vivo treatments of A. ocellatum-infested snapper with a 1 h freshwater bath and 200 ppm H2O2 showed promising results. This is the first report of A. ocellatum infestation in milkfish and mangrove red snapper in the Philippines.
    • Article

      Mass production in concrete tanks of sugpo Penaeus monodon Fabricius spawners by eyestalk ablation 

      JH Primavera, E Borlongan & RA Posadas - Fisheries Research Journal of the Philippines, 1978 - Fisheries Research Society of the Philippines
      Two batches of 196 and 181 P. monodon females were ablated on one eyestalk in March and July 1977, respectively, and a control batch of 180 unablated females was stocked in July 1977. The females were stocked with males in 120-ton concrete tanks with partial flowthrough of water and fed salted mussel (Modiolus metcalfei ) at 15% body weight daily. Total number of spawnings was 82 for the March-ablated group, 3 for the July-ablated group and 4 for the July unablated group. Maturation and mortality in relation to the moult cycle and tank plus water conditions are discussed.
    • Article

      Mass-production of Tetraselmis chuii in seawater 

      RQ Gacutan & MCL Baticados - Kalikasan: The Philippine Journal of Biology, 1979 - University of the Philippines at Los Baños
    • Article

      Maturation and spawning of Penaeus indicus using different ablation methods 

      S Makinouchi & J Honculada-Primavera - Aquaculture, 1987 - Elsevier
      Wild immature Penaeus indicus females (11.5 ± 3.1 g body weight) were ablated by pinching, cautery or tying of one eyestalk, and stocked with control (unablated) females and males (9.2 ± 1.5 g) in a 12-m3 maturation tank. Full ovarian maturation and spawning were attained 4 days after ablation/stocking in all treatments, with a peak at 5–6 days. Seventy-five percent of ablated and unablated females spawned during the study period. Average egg numbers from complete spawns increased with size of females for all treatments. There was no significant difference in fecundity of complete spawns from the various treatments. However, hatch rates of unablated P. indicus were significantly higher than eyestalk-pinched females but not those ablated by cautery and tying. Similarly, survival after the 15-day period was lowest among pinched females.
    • Article

      Measures of egg quality in induced spawns of the Asian sea bass, Lates calcarifer Bloch 

      JN Nocillado, VD Peñaflorida & IG Borlongan - Fish Physiology and Biochemistry, 2000 - Springer Verlag
      The egg morphometry and lipid and protein components were determined in induced spawns (n = 14) of the sea bass, Lates calcarifer, to identify measures of egg quality. Based on fertilization and hatching rates, the spawns were classified either in Group I, (zero fertilization) or Group II (where fertilization and hatching occurred). The egg morphometry did not differ between the two groups (p > 0.05). The total lipid was higher in Group II than in Group I, although the difference was not significant (p > 0.05). The EPA and linoleic acid were significantly higher in Group II (p < 0.05). There were positive correlations between the total saturated fatty acids and fertilization rate (p < 0.05; r = 0.58), the total saturated fatty acids and percentage of normal zygotes (p < 0.02; r = 0.62), and DHA and the percentage of normal zygotes (p < 0.04; r = 0.56). The total protein and FAAs were higher in Group I than in Group II, but the differences were not significant (p > 0.05). Proline, glycine, p-ethanolamine, and aspartic acid were significantly higher in Group II (p < 0.05), while tyrosine and glutamic acid were significantly higher in Group I (p < 0.05). Phosphoserine and fertilization rate were positively correlated (p < 0.03; r = 0.60), as well as aspartic acid and hatching rate (p < 0.05; r = 0.54). Arginine was negatively correlated with fertilization rate (p < 0.03; r = -0.61) and the percentage of normal zygotes (p < 0.03; r = -0.63). Serine was inversely correlated with yolk volume of the newly-hatched larvae (p < 0.03; r = -0.77). The moisture content of the eggs, which was significantly higher in Group II than in Group I (p < 0.03), was directly correlated with the FAAs:protein ratio (p < 0.03; r = 0.76). The present results reveal egg components that may be used as quality measures in induced spawns of sea bass, a euryhaline teleost that spawn pelagic eggs containing an oil globule.
    • Article

      The mechanics of mass occurrence and recruitment strategy of milkfish Chanos chanos (Forsskal) fry in the Philippines 

      P Buri & G Kawamura - Memoirs of the Kagoshima University Research Center for the South Pacific, 1983 - Kagoshima University Research Center for the South Pacific
      The daily and hourly catch of milkfish Chanos chanos (Forsskal) fry in the coast of Hamtic, Panay Island in the Philippines was recorded over a period of 16 weeks, and correlated with time, location, types of gear, and lunar and tidal variations. About 4000 fry were marked and released, scanning electronmicroscopy was employed to examine the feeding habit of the fish. The results obtained suggest an active process governing the occurrence and movement of fry in coastal waters. The appearance of the fry is related to the developmental stage of the fry and is subject to lunar modulation. Interaction with predators in coastal waters has produced diverse and selective antipredator adaptations, such as body transparency, the use of timing (seasonality, tidal conditions), and distribution patterns. The maximization of resource utilization and minimization of resource sharing also occurs in a seasonal basis. High mortality rate in shallow coastal waters is counteracted by high recruitment rate and specific behavioural and physiological adaptations to ensure successful and fast colonization of backwaters. It is suggested that higher food availability in the nursery ground exerts a stronger selective pressure over predation, and act as the major force in the migration from offshore to shore waters.
    • Article

      Mercury and selenium interaction: A review 

      MLA Cuvin-Aralar & RW Furness - Ecotoxicology and Environmental Safety, 1991 - Elsevier
      This paper reviews studies on mercury and selenium interaction. It includes the effects of selenium on mercury toxicity on the organism, organ/tissue, and subcellular levels. The paper also touches on possible mechanisms for the "protective action" of selenium against mercury toxicity and deals briefly with the synergism between the two elements.