Conference Proceedings
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Conference paper
Development of integrated multi-trophic aquaculture using sea cucumber
- In K Gruenthal, M Rust, P Olin & E Trentacoste (Eds.), Genetics in Aquaculture: Proceedings of the 42nd U.S.-Japan Aquaculture Panel Symposium, La Jolla, CA, October 1, 2014, 2017 - United States Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service
Series: NOAA technical memorandum; NMFS-F/SPO-168In Southeast Asian countries, aquaculture production continues to increase. Environmental deterioration associated with water and sediment eutrophication by aquaculture effluent has been problematic, sometimes resulting in disease outbreaks and fish kills due to hypoxia and hydrogen sulfide poisoning. Integrated multi-trophic aquaculture (IMTA) is one of the promising measures for sustainable aquaculture. In this study, a box model estimation of nitrogen (N) budget based on experimental data and values from literature was made for a system of sandfish (Holothuria scabra) in sea cage IMTA with milkfish (Chanos chanos) and Elkhorn sea moss (Kappaphycus alvarezii). Information on stocking density, stocking size, mortality, growth, feed ration, feed assimilation, NH4-N production and NH4-N absorption of these species was obtained from a series of experiments and existing literature. In the production system 26 g milkfish were cultured in a 5 x 5 x 4 m cage at the stocking density of 36.7 ind/m3 with the initial feeding ration of 10% of body weight which was gradually decreased to 4% over time; 10 g sandfish were cultured in a cage with the same bottom area as milkfish cage hanged under the milkfish cage to trap particulate N waste (i.e. feces and leftover feed) at the stocking density of 35 ind/m2; the stocking weight of Elkhorn sea moss line culture was 10 kg; culturing period was 200 days. It was estimated that milkfish culture cumulatively produced 145 kg of particulate N, and milkfish and sandfish together produced 60 kg of NH4-N in 200 days of culture. Daily assimilation rate of the particulate N by sandfish ranged 3.4 - 12.4%, and 4.3% of the particulate N was estimated to be removed by sandfish in 200 days of culture. Daily absorption rate of NH4-N by Elkhorn sea moss increased exponentially with time and reached 100% after 125 days of culture. Cumulative NH4-N was estimated to be depleted after 162 days of culture. For complete utilization of particulate N by the end of culture, sandfish stocking density should be 805 ind/m2, which is 200 times as high as that in existing sandfish aquaculture operations. -
Conference paper
Expressions of molt-inhibiting hormone (MIH) and extracellular signal-regulated kinase (ERK) during the molting stages of the giant mud crab, Scylla serrata
- In Proceedings of the DLSU Research Congress 2017, De La Salle University, Manila, Philippines, June 20-22, 2017, 2017 - De La Salle UniversitySurvival and growth of mud crabs and any other crustaceans depend on molting. Molting is influenced by several hormones, two of which are Molt-Inhibiting Hormone {MIH} and a molt promoting hormone, the Extracellular Signal-regulated Kinase (ERK). Controlling and synchronizing the molting of the crabs would be a big boost to the mud crab industry, especially in the production of soft shell crabs. The best way to control molting would be to stock juvenile crabs of the same molting stage together. In this study, hormone expressions were analyzed using quantitative Real-Time Polymerase Chain Reaction (1RT-PCR). Molt stages of 36 juvenile S. serrata were established based on MIH and ERK expression levels that was analyzed using Principal Component Analysis (PCA). One group of six individuals had MIH value equal to zero and presumed to be in the PR stage. The rest of the crabs had values for MIH and were presumed to be in the PM-IM stage. The value of ERK for the PM-IM stage was higher at 24.79 than in the PR stage at 21.67. Based on the data gathered, morphological markers may now be identified to standardize hormone expression. This would be the first study concerning the comparison of hormones during molting. -
Conference paper
Morphological development and survival of Philippine silver therapon larvae, Leiopotherapon plumbeus (Kner, 1864) reared under different feeding schemes
- In Proceedings of the DLSU Research Congress 2016, De La Salle University, Manila, Philippines, March 7-9, 2016, 2016 - De La Salle UniversityPhilippine silver therapon, Leiopotherapon plumbeus, locally known as ayungin, is an endemic fish species in the country. The demand for silver therapon remained high despite the decline of its population and commercial catches. Taking into account the potential of this species for stock enhancement, this study focused on developing an initial feeding strategy necessary to provide potential L. plumbeus juveniles for aquaculture. The experiment conducted was a short duration 10-day feeding experiment which used different feeding schemes utilizing live food organisms [Brachionus (B), Moina (M), co-fed with BM, Chlorella (C) and filtered lake water (L)]. Morphometric measurements were evaluated to assess growth performance of larvae among different feeding schemes. Survival rate was determined at the end of feeding experiment at 9 DAH (days after hatching). Growth parameters of L. plumbeus larvae reared under different feeding schemes showed significant differences starting at 5 DAH (P < 0.05) onward. After a total of 10 days, a significant decline in fish larval samples was observed under two feeding schemes (C and L). BM has a significant higher rate of survival (18.07 ± 7.09%) compared to other treatments. B. rotundiformis (15-20 mL-1) can be considered as a starter food for silver therapon larviculture and M. micrura (5-10 mL-1) can be utilized during an assumed co-feeding phase at 6 DAH. -
Conference paper
Salt tolerant Nile tilapia production: Prospects in aquaculture
- In MC Remany & J Kumar (Eds.), Proceedings of the India Tilapia Summit 2014 and 2nd Edition of the Dr. E. G. Silas Endowment Lecture, 18th December 2014, Vijayawada, India, 2016 - Rajiv Gandhi Centre for Aquaculture (MPEDA)In the Philippines, salt tolerant Nile tilapia strains have been developed and promoted for culture to increase tilapia production in brackishwater pond systems previously dedicated for milkfish and/or penaeid shrimp culture. This was mainly done to address the decline in the production of such major commodities in ponds and/or cages brought about by diseases and mass fish kills caused by intensified culture methods. The present paper focuses on the different salt tolerant Nile tilapia stocks that have been developed and disseminated in the Philippines, the culture practices involved, as well as the prospects for profitable production of Nile tilapia in saline conditions. -
Conference paper
Community-based stock enhancement of abalone, Haliotis asinina in Sagay marine reserve: Achievements, limitations and directions
- In K Hajime, T Iwata, Y Theparoonrat, N Manajit & VT Sulit (Eds.), Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium … Strategy for Fisheries Resources Enhancement in the Southeast Asian Region, Pattaya, Thailand, 27-30 July 2015, 2016 - Training Department, Southeast Asian Fisheries Development CenterThe Sagay Marine Reserve (SMR) under the National Integrated Protected Area System (NIPAS) is one of the many reef areas in the Visayan Sea in the central part of the Philippine archipelago. The SMR covers 32,000 ha or 59% of coastal waters north of the mainland Sagay City. Donkey’s ear abalone is one of the most sought mollusks traded by small-scale fishers in Molocaboc Island located within the SMR. High buying prices in local and international markets compared with other fish catch motivated fishers to target abalone and caused its overfishing. SEAFDEC/AQD, with support from the Government of Japan Trust Fund (JTF), conducted a community-based stock enhancement through a tri-party collaboration between the fisherfolks of Molocaboc Island, the Sagay local government at the village and city levels, and SEAFDEC/AQD. The study showed that the decision and implementation of stock enhancement and the definition of its objectives and relevance involves the strong engagement with stakeholders. For over a period of eight years (2007-2014), we learned that stock enhancement necessarily involve high financial investments and enormous transaction cost over a long period of time which are often not affordable to local governments of coastal communities in Southeast Asia. Thus, community-based collaborations may help achieve enhancement and restocking goals. -
Conference paper
Fishery resource enhancement: An overview of the current situation and issues in the southeast Asian region
- In K Hajime, T Iwata, Y Theparoonrat, N Manajit & VT Sulit (Eds.), Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium … Strategy for Fisheries Resources Enhancement in the Southeast Asian Region, Pattaya, Thailand, 27-30 July 2015, 2016 - Training Department, Southeast Asian Fisheries Development CenterThe total global production from capture fisheries has plateaued since the mid 90s. This stagnation in production or reduced productivity of the world’s coastal and marine wild fisheries is caused by overfishing and degradation of habitats through coastal development and destructive fishing methods. Reports have shown that if the current fishing trends continue, all of the commercial fisheries will have collapsed by 2050. To boost production, scientists, fisheries managers, government agencies, and NGOs have been looking at ways of enhancing fish stocks. Replenishing depleted stocks may be done by regulating fishing effort, restoring degraded nursery and spawning habitats or through resource enhancement. Resource enhancement using individuals reared in aquaculture facilities or seed stocks abundant in the wild is becoming a popular method of supplementing depleted stocks. It is one of the many strategies that could help address the decreasing fisheries production in the wild. A brief history of resource enhancement, the aquatic species released in the different countries in the region, the reasons for releasing stocks, and the issues involved, are discussed briefly in this paper. Among the main reasons for resource enhancement are to increase production or enhance stocks and increase food supply and/or family income. Other reasons include protection of endemic and maintenance of endangered species, rehabilitation of degraded natural habitats and for recreation fisheries, among others. Age or size of seeds, seed quality, genetics, governance, economics, biodiversity conservation, politics, and the introduction of exotics are among the resource enhancement issues identified in the region. -
Conference paper
Aquaculture-based restoration and stock enhancement of tiger shrimps in the Philippines
- In K Hajime, T Iwata, Y Theparoonrat, N Manajit & VT Sulit (Eds.), Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium … Strategy for Fisheries Resources Enhancement in the Southeast Asian Region, Pattaya, Thailand, 27-30 July 2015, 2016 - Training Department, Southeast Asian Fisheries Development CenterIn central Philippines, the Aquaculture Department of the Southeast Asian Fisheries Development Center (SEAFDEC/AQD), with strong collaboration and support from the Research Institute for Humanity and Nature (RIHN) of Kyoto, Japan, has been looking into the stock enhancement of tiger shrimp Penaeus monodon in the New Washington Estuary (NWE), province of Aklan, central Philippines. The NWE was a productive fishing ground that has been suffering from degenerating brackishwater fisheries and estuarine environment. Average daily catch declined from 24 kg in 1970s to only 0.7 kg at present. Shrimp fisheries, the most important livelihood, declined in quality and quantity. Tiger shrimps were abundant in catch until the early 1990s when these were observed to decline in volume, replaced by smaller and cheaper species. This was coincidental with the rapid decline in mangrove cover for ponds and huge increase in fishing pressure. It is clear that crucial interventions are required to restore the tiger shrimp fisheries in the NWE in order to increase income of local fishers, while promoting reduction of fishing gears and restoration of mangroves. Stock enhancement of tiger shrimps shows good potential in answering these needs. Site-specific assessments were conducted to evaluate prospects of shrimp stock enhancement in NWE. Conservative simulations of capture of released stocks showed that fishers can increase income by 300%. To decrease fishing pressure in the area, number of gears per fisher may have to be reduced but shrimp catches will be relatively high-priced. Comparative experiments using aquaculture techniques were done to identify strategies especially in the delicate intermediate acclimation rearing. Aquaculture protocols like those for pond preparation were also adapted to be used in a mangrove pen nursery rearing system for shrimps. Supplemental feeding with formulated feeds increased carrying capacity of the culture area, while enhancing growth and survival of stocks. Culture experiments showed that shrimps grow to 0.5 g within 1 mo and >1g in 2 mo. High stocking density of 40-60 shrimps m-2 can be used for <2 mo rearing in a mangrove pen. Release experiments showed that 60-d old shrimps have higher chances of survival when released in the estuaries. With strong support from local communities, government and other sectors, together with effective management and law enforcement, aquaculture-based stock enhancement of tiger shrimps can be a viable intervention to restore livelihood and promote estuarine rehabilitation in the NWE. -
Conference paper
SEAFDEC/AQD stock enhancement initiatives: Release strategies established
- In K Hajime, T Iwata, Y Theparoonrat, N Manajit & VT Sulit (Eds.), Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium … Strategy for Fisheries Resources Enhancement in the Southeast Asian Region, Pattaya, Thailand, 27-30 July 2015, 2016 - Training Department, Southeast Asian Fisheries Development CenterSEAFDEC/AQD’s Stock Enhancement Program started in 2001 with the first stock enhancement initiative on mud crab Scylla spp. funded by the European Commission. This was followed by another stock enhancement program in 2005 supported by the Government of Japan Trust Fund with seahorses Hippocampus spp., giant clam Tridacna gigas, abalone Haliotis asinina, and sea cucumbers Holothuria spp. as priority species. This paper discusses the release strategies that have been established for giant clam, abalone and mud crab. -
Conference paper
Paradigm shifts in mangrove rehabilitation in Southeast Asia: Focus on the Philippines
- In HG Palis, SA Pasicolan & CI Villamor (Eds.), Proceedings of the 1st ASEAN Congress on Mangrove Research and Development, 3-7 December 2012, Manila, Philippines, 2014 - Department of Environment and Natural Resources - Ecosystems Research and Development Bureau (DENR-ERDB)Mangrove rehabilitation has a long history in the Philippines dating back to the 1930s. The standard practice is the planting of bakhaw Rhizophora propagules by paid community members (or volunteers) in seafront sites selected during spring low tides. In 2009, the Community-based Mangrove Rehabilitation Project (CMRP) of the Zoological Society of London was established to: (a) rehabilitate abandoned government-leased fi shponds into healthy mangroves; (b) increase coastal protection, food resources, and livelihood income through sustainable management of mangroves; and (c) re-establish the legally mandated mangrove ‘greenbelt’ along the coast. Over four years, the CMRP has planted the following in various partner sites in Panay and Guimaras: (a) 58,000 seeds or wildings bagged in nurseries by 3,000 participants, and (b) 99,000 seedlings/wildings outplanted by 4,000 planters in ~20 ha of greenbelts and abandoned ponds. The species are mainly bungalon/piapi Avicennia marina, pagatpat Sonneratia alba, and to a lesser extent, bakhaw Rhizophora. The planters include high school/college students and teachers, members of people’s organizations, barangay and municipal government employees, BFAR and DENR staff , and civil society organizations. The extensive CMRP trials have yielded signifi cant learnings, many of them paradigm shifts from present protocols, as included in the 20 Golden Rules of Mangrove Rehabilitation. A manual that documents these learnings with concrete examples based on CMRP monitoring of fi xed quadrats and other standardized protocols, is currently in press. Some of these protocols are the following: (a) planting site: shift from seafront sites to abandoned ponds (whenever possible); (b) time of site selection: during (low tide of) Neap Tide rather than Spring Tide; (c) species selection for seafront sites: the ecologically correct bungalon/piapi and pagatpat, rather than the easy-to-plant but unsuitable bakhaw; (d) sources of planting materials: use of available wildings is harvesting nature’s excess (equivalent to withdrawing from ‘seedling banks’), which also saves time; (e) labor: “No Pay” planting is based on the premise that labor contributed by the community provides the basis for ownership, thereby obligating them to nurture the plants to maturity and validating their role as de facto managers of mangrove resources. Similar mangrove initiatives have been observed elsewhere in Southeast Asia, as follows: (a) barriers/breakwater in MaIaysia, Vietnam, and Thailand; (b) use of wildings in Malaysia; and (c) mangrove ecoparks/reserves in Singapore, Thailand, Vietnam and Brunei. -
Conference paper
Fish biodiversity and incidence of invasive fish species in an aquaculture and non-aquaculture site in Laguna de Bay, Philippines
- In C Biscarini, A Pierleoni & L Naselli-Flores (Eds.), Lakes: The Mirrors of the Earth. Balancing Ecosystem and Human Wellbeing, 2014 - Science4PressLaguna de Bay is the Philippines' largest inland water with 900 km2 surface area. The lake has been assessed as hypereutrophic (Rohani and Roblo, 1984) to dystrophic (Barril and Tumlos, 2002). To make use of the lake's natural productivity a pilot aquaculture project started in 1971 (del Mendo and Gedney, 1979). The aquaculture industry in the lake rapidly developed, mainly using species not native to the lake. Since then, the lake has become a major source of fish in Metro Manila and the adjacent provinces. An assessment of the impact of aquaculture in the lake showed increased total finfish biomass in the lake; ecotrophic efficiency of phytoplankton increased; and the calculated total net primary production decreased by a factor of two compared to the pre-aquaculture period (de los Reyes, 1993). The dominant species cultured in Laguna de Bay are introduced species. After more than 40 years the lake is now populated with non-native species including species that are considered invasive and nuisance. Many of these species were deliberately introduced for aquaculture and there are those that were considered accidental introductions like ornamental fish cultured in ponds within the lake's watershed. To assess the impact of aquaculture in localized areas in the lake, a study was conducted to monitor diversity in the fisheries resources of the lake at two adjacent, but distinctly different sites: the West Cove (WC), an open fishery area, with no aquaculture and the East Cove (EC) which is an aquaculture site with cages for Nile tilapia, bighead carp, giant freshwater prawn. -
Conference paper
Low-cost production of the marine thraustochytrid isolate, Schizochytrium sp. LEY7 as larval live feed enrichement for the mangrove snapper, Lutjanus sp.
- In CI Hendry (Ed.), Larvi ’13 – Fish & Shellfish Larviculture Symposium, 2013 - Laboratory of Aquaculture & Artemia Reference Center, Ghent UniversityThis study demonstrates the potential of low-cost production substrates in mass producing the Schizochytrium sp. LEY7 for maximum DHA production. High biomass yield was achieved by optimizing the culture conditions particularly the incubation temperature and salinity levels. Preliminary data on feeding trials have shown promising results and therefore confirmatory experiments need to be conducted to verify the results obtained. -
Conference paper
The Agusan Marsh and the Agusan River Basin: The need for science-based development and management
- In MLC Aralar, AS Borja, AL Palma, MM Mendoza, PC Ocampo, EV Manalili & LC Darvin (Eds.), LakeCon2011: Building on the pillars of Integrated Lake Basin Management (Second National Congress on Philippine Lakes), 2013 - PCAARRD-DOST
Series: Summary of Proceedings No. 1/2013 -
Conference paper
Resiliency of small-holder fishfarmers to climate change and market prices in selected communities in the Philippines
- In MG Bondad-Reantaso & RP Subasinghe (Eds.), Enhancing the contribution of small-scale aquaculture to food security, poverty alleviation and socioeconomic development, 2013 - FAO
Series: FAO fisheries and aquaculture proceedings; 31A rapid assessment of the resiliency of small-holder fishfarmers in selected communities in the Philippines was conducted to gather the fishfarmers’ observations and insights about climate change and market prices, and the impacts of climate change on their environment, livelihood and life, in general, and to learn measures they have adopted to cope with adverse situations. The study sites were communities that were undertaking aquaculture livelihood, with technical support from the Aquaculture Department of the Southeast Asian Fisheries Development Centre or SEAFDEC/AQD and logistical assistance from their local governments and international and private donors. The climate change phenomena observed in the study sites were flash floods, sea level rises, increases in temperature, stronger waves, and longer dry season (drought). The major ecological impacts were mortality of marine flora and fauna, destruction of aquaculture facilities (cages and ponds), disruption of aquaculture protocol, and frequent occurrence of fish diseases. As a result, fishfarmers suffered substantial financial losses that forced them to either borrow more money (most are already heavily indebted), or stop operation until financial support is available. To help each other survive common hardships, the fishfarmers resorted to the Philippine traditional “bayanihan” system or collective action for their common good. Rapid assessment studies can only provide initial insights on the situation in the community. A more comprehensive and integrated methodology to include various dimensions (human, ecological, economic, technological and institutional) is recommended in future studies on climate change. -
Conference paper
Sustaining aquaculture by developing human capacity and enhancing opportunities for women
- 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; NACAPeople 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. -
Conference paper
Evaluation of nutritional condition of juvenile sandfish (Holothuria scabra)
- In CA Hair, TD Pickering & DJ Mills (Eds.), Asia-Pacific tropical sea cucumber aquaculture. Proceedings of an international symposium held in Noumea, New Caledonia, 15-17 February 2011, 2012 - Australian Centre for International Agricultural Research
Series: ACIAR Proceedings; No. 136It is important to accurately evaluate the wellbeing or nutritional condition of organisms when monitoring the wild stock conditions and improvement in aquaculture techniques; however, reliable nutritional condition indexes have not been established for sea cucumbers. In this study, the effects of starvation on condition factor (body weight / body volume), coelomic fluid constituent (protein, carbohydrate and cholesterol) concentrations and coelomic fluid density were analysed in an attempt to establish a method to determine nutritional condition in juvenile sandfish (Holothuria scabra). Body length, breadth and weight of juveniles produced at the sea cucumber hatchery of the Aquaculture Department, Southeast Asian Fisheries Development Center, were measured after anaesthetisation with 2% menthol-ethanol. Coelomic fluid protein level was analysed by the bicinchoninic acid method. Carbohydrate level was analysed by the phenol – sulfuric acid method. Cholesterol level was analysed by the Zak method. Coelomic fluid volume and coelomic fluid weight were measured. Starvation caused a concomitant decrease in body length, breadth and weight, resulting in no net change in the condition factor. This result indicated that condition factor cannot be used as a nutritional condition index. Coelomic fluid constituent level could be measured with a small volume of sample (i.e. 10–20 μL). Although no clear pattern was observed in coelomic fluid protein and cholesterol levels during the starvation trial, carbohydrate level increased, as did coelomic fluid density. These results suggest that coelomic fluid density and carbohydrate level may be used as indexes for nutritional condition of sandfish without sacrificing the animal. -
Conference paper
A lifetime of mangrove research, management and advocacy
- In F Dahdouh-Guebas & B Satyanarayana (Eds.), Proceedings of the International Conference ‘Meeting on Mangrove ecology, functioning and Management - MMM3’, Galle, Sri Lanka, 2-6 July 2012, 2012 - Vlaams Instituut voor de Zee (VLIZ)
Series: VLIZ Special Publication; 57Apart from a decade of undergraduate teaching, my professional life has been directly or tangentially devoted to mangrove issues. Strife in my native Mindanao pushed my family and me to the peace and quiet of Panay Is. in central Philippines and to research on marine shrimp, the commercial superstars of the mangrove macrobenthos. My early focus was on broodstock development, larval rearing and pond grow-out of penaeids, mainly the mangrove-associated giant tiger prawn Penaeus monodon and the white shrimp P. indicus: Because brackishwater ponds are the dominant aquaculture system in the Philippines, species whose rearing requirements mimic the estuarine habitat, e.g., fluctuating salinity levels, have become the crops of choice. Published papers from this period include a classification of P. monodon egg quality types (Fig. 1: Primavera and Posadas 1981) which allows hatchery technicians to predict larval numbers and the corresponding tank water volume to prepare. -
Conference paper
Ability of sandfish (Holothuria scabra) to utilise organic matter in black tiger shrimp ponds
- In CA Hair, TD Pickering & DJ Mills (Eds.), Asia-Pacific tropical sea cucumber aquaculture. Proceedings of an international symposium held in Noumea, New Caledonia, 15-17 February 2011, 2012 - Australian Centre for International Agricultural Research
Series: ACIAR Proceedings; No. 136Due to frequent viral disease outbreaks, a large proportion of shrimp aquaculture in South-East Asian countries has switched from black tiger shrimp (Penaeus monodon) to P. vannamei, an exotic species originally imported from Latin America. One of the causes of disease outbreaks is thought to be poor water and sediment conditions in the shrimp ponds, which may aggravate disease symptoms. To obtain basic information for co-culture methods of black tiger shrimp and sandfish (Holothuria scabra) for possible mitigation of shrimp-pond eutrophication and prevention of disease outbreaks, basic laboratory experiments were conducted at the Southeast Asian Fisheries Development Center—Aquaculture Department in Iloilo, the Philippines. A feeding trial of juvenile sandfish showed that they do not grow well with fresh shrimp feed on hard substrate. Another trial indicated that sand substrate enhances the growth of juvenile sandfish fed with shrimp feed. A feeding trial using shrimp tank detritus, shrimp faeces and Navicula ramosissima (a benthic diatom) as food sources showed that sandfish grew fastest with the faeces, followed by detritus and N. ramosissima. Dissolved oxygen consumption and acid-volatile sulfur levels in the shrimp tank detritus were reduced by sandfish feeding. This suggests that sandfish are capable of growing with organic matter in shrimp ponds, and can bioremediate shrimp-pond sediment. -
Conference paper
Overview of sea cucumber aquaculture and sea-ranching research in the South-East Asian region
- In CA Hair, TD Pickering & DJ Mills (Eds.), Asia-Pacific tropical sea cucumber aquaculture. Proceedings of an international symposium held in Noumea, New Caledonia, 15-17 February 2011, 2012 - Australian Centre for International Agricultural Research
Series: ACIAR Proceedings; No. 136South-East Asia has traditionally been the global centre of production of tropical sea cucumbers for Chinese markets. Early research into culture methods took place outside this region, notably in India, the Pacific region and China. However, recent investment in Holothuria scabra (sandfish) culture has led to some significant advances within this region. The Philippines and Vietnam have been at the forefront of recent efforts, with involvement from substantial national programs and local institutions as well as international donors and scientific organisations. Smaller programs are ongoing in Thailand, Malaysia and Indonesia. Recent advances and simplifications in hatchery techniques are a major step forward, having promoted the development of experimental-scale sea-ranching ventures, and given rise to a small, commercial pond-based culture industry in Vietnam. Technology developments in nursery systems are likely to provide opportunities for culture enterprises in a broader range of environments than is now possible. A major research thrust in the Philippines towards developing cooperative sea-ranching enterprises has demonstrated good potential, and institutional/legislative arrangements to ensure adequate property rights have been tested. Rotational culture with shrimp is proving successful in Vietnam, while the possibility of proximate co-culture of sandfish and shrimp has largely been ruled out. Small-scale experiments in the Philippines raise the possibility of co-culture in ponds with a number of finfish species. Current research directions are looking at diversifying technology to increase success in a range of coastal conditions, better understanding the social and biophysical conditions required for success, and finding ways of effectively scaling-out developed systems and technology. -
Conference paper
Recent developments in the study and surveillance of koi herpesvirus (KHV) in Asia
- In MG Bondad-Reantaso, JB Jones, F Corsin & A Takashi (Eds.), Diseases in Asian Aquaculture VII: Proceedings of the Seventh Symposium on Diseases in Asian Aquaculture, Taipei, Taiwan 20-26 June 2008, 2011 - Fish Health Section, Asian Fisheries SocietyKoi herpesvirus infection causes significant mortalities in common carp (Cyprinus carpio carpio), koi carp (Cyprinus carpio koi) and ghost carp (common x koi cross, Cyprinus carpio koi). Outbreaks have been reported in many countries worldwide i.e. UK, Germany, Israel, USA, Belgium, South Africa, Switzerland, The Netherlands, France, Denmark, Austria, Italy, Luxemburg and Poland. The first outbreaks attributed to KHV in Asian countries were reported from Hong Kong in 2001; Indonesia in 2002; Taiwan in 2002; Japan in 2003; Thailand in 2005; and Singapore in 2005. Thereafter, research studies embarked on KHV focused on pathogenicity, cell line susceptibility, fish size susceptibility, predilection to fish organs, persistence in fish, vaccine development and application, surveillance and gene sequence analyses of KHV strains. To date, annual active surveillance of the virus in Cambodia, Lao PDR, Myanmar, the Philippines and Vietnam showed that these countries were free of KHV from 2004 to 2007. Several strains of KHV apparently affect koi and common carp in this region indicating that transboundary movement of the virus has occurred not only in Asia but also from Europe and the Americas. The extensive international trade in live ornamental koi fish has largely contributed to the global spread of KHV. Hence, KHV disease (KHVD) was recently added to the list of notifiable diseases of the World Organisation of Animal Health or the Office International des Epizooties (OIE), an indication of the global significance of this viral infection. -
Conference paper
Using mangroves for aquaculture - Why should we?
- In M Troell, T Hecht, M Beveridge, S Stead, I Bryceson, N Kautsky, A Mmochi & F Ollevier (Eds.), Mariculture in the WIO region - Challenges and Prospects. Proceedings from Workshop on Mariculture, December 2009, Zanzibar, 2011 - Western Indian Ocean Marine Science Association (WIOMSA)Although brackishwater ponds have been a major factor in mangrove loss in Southeast Asia where aquaculture is centuries-old, the “No Touch option” for mangroves is a luxury that most countries in the region cannot afford. So the question is not whether mangroves and aquaculture are compatible, but how best to integrate them so that mangrove services are maximized while some benefits from aquaculture remain? A review of “mangrove-friendly aquaculture” or MFA in Southeast Asia shows that while some technologies are traditional, others are government-driven (rather than research-based, to mitigate social conflict). MFA may be sited in subtidal waterways (e.g., seaweeds, bivalves) or the intertidal forest -- Hong Kong gei wai, Indonesian tambak tumpang sari, Vietnam mixed mangrove-shrimp farm systems and mangrove pens for mudcrab in Malaysia.
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