Organized by SEAFDEC Aquaculture Department with funding from the Government of Japan, the 3-day International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia aims to promote and augment regional initiatives on resource enhancement and sustainable aquaculture practices, and to contribute to poverty alleviation, livelihood and food security.

Recent Submissions

  • Book | Conference publication

    Resource enhancement and sustainable aquaculture practices in Southeast Asia: challenges in responsible production of aquatic species : proceedings of the international workshop on resource enhancement and sustainable aquaculture practices in Southeast Asia 2014 (RESA) 

    MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.) - 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The conference was held in order to promote and augment regional initiatives on resource enhancement and sustainable aquaculture practices, and to contribute to poverty alleviation, livelihood and food security in Southeast Asia. The contributions of the selected participants during the conference which are contained in this volume are cited individually.
  • Conference paper

    Is small-hold tropical aquaculture in a genetic plunge towards extinction? 

    RW Doyle - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Tropical shrimp aquaculture is in a disease-induced crisis of lost production. The response to this crisis currently focuses on microbiology and pathology, quarantine, and transboundary transfer of shrimp. The crisis also involves an interaction between shrimp genetics and various human interests including protection of intellectual property. Breeders of high-quality strains generally employ (and are encouraged to employ) some form of breeder lock that generates inbreeding when broodstocks are copied . Smaller hatcheries sell these copied, inbred shrimp to farmers, who thereby increase the likelihood of losing their crops to disease. The joint behavior of breeders, hatcheries and farmers causes inbreeding to accumulate in tropical regions.

    The depressive effect of inbreeding on disease resistance is exceptionally strong in shrimp, as shown in a re-analysis of published field and experimental data. Inbreeding increases the severity and frequency of disease through a variety of mechanisms. We have relatively few, marker-based estimates of accumulated inbreeding in any non-pedigreed shrimp aquaculture system. Simulation shows, however, that locked post larvae (PLs) can be distinguished from copies in broodstocks and farm ponds, given appropriate analysis of genetic markers.

    Culture of stocks certified to be free of specified pathogens (specific pathogen free or SPF stocks) is strongly recommended and only SPF stocks can now be legally imported into most jurisdictions. These recommendations are appropriate, beneficial and necessary. But insofar as they increase the commercial value of proprietary genetic strains, such regulations may also increase the likelihood of copying, and thus inbreeding at farm level and ever-increasing susceptibility to disease and climate stress (Doyle, 2014a).

    The intellectual property value of disease-resistant strains will be extremely high and intellectual property rights are fundamental to science-based economic innovation. Breeders will, and must, continue to protect their genetic improvement programs with genetic locks, especially in regions where judicial sanctions are ineffective. The regulatory objective should be to encourage biosecurity and genetic progress while discouraging copying and consequent inbreeding.

    The current consensus that inbreeding is unimportant may therefore be out of date. Inbreeding may be amplifying the severity of diseases (including the major current threats: white spot syndrome virus or WSSV, infectious hypodermal and hematopoietic necrosis virus or IHHNV and early mortality syndrome or EMS (acute hepatopancreatic necrosis disease or AHPND). Continuing to ignore the interaction between inbreeding and disease may become a fatal error for tropical shrimp aquaculture.
  • Conference paper

    Status of resource management and aquaculture in Malaysia 

    A Yusoff - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Malaysia is a maritime nation and its fishing industry is a source of income for 134,000 fishermen. In 2012, the fisheries sector produced 1.7 million tons of fish valued at RM10.8 billion and generated trade worth RM6 billion. The landings from capture fisheries are expected to increase from 1.32 million tons in 2010 to 1.76 million tons in 2020 at an annual growth rate of 2.9%. In 2012, 65% of total catch was contributed by the coastal fisheries as compared to 35% from deep sea fishing. Landing from deep sea fishing is expected to rise from 381,000 tons in 2012 to 620,000 tons in 2020. Deep sea fishing has been identified for its potential to contribute to the increase in the country s fish production. With a growing population and an increasing preference for fish as a healthy source of animal protein, the National Agro-food Policy (2011-2020) estimated that the annual demand for fish will increase to 1.93 million tons by the year 2020. The Department of Fisheries (DOF) has developed the Capture Fisheries Strategic Management Plan (2011-2020) based on three main documents i.e.; National Agro-food Policy (NAP, 2011-2020), Department of Fisheries Strategic Management Plan (2011-2020), and Malaysia National Plan of Action on Sustainable Fisheries for Food Security towards 2020.

    Aquaculture is now being promoted in Malaysia as an important engine of growth and eventually to become the mainstay of the nation s economy. Situated in a region with abundant supply of land and water, two determinant factors for aquaculture activities, Malaysia has always strived to ensure that this sector is not sidelined in their development efforts. With a growing population and an increasing preference for fish as a healthy source of animal protein, it has been estimated that the annual demand for fish will increase to 1.7 million tons in 2011 and further to 1.93 million tons by 2020. From the present annual aquaculture production of about 525,000 tons, this output would need to be raised to 790,000 tons to meet the projected demand by 2020. In a move to develop the aquaculture industry, the DOF, has initiated the Aquaculture Industrial Zone (AIZ) Program involving the development of 49 zones, located across Malaysia, which will be used for culture of various types of high value aquatic species. The DOF has identified several strategic areas that would be developed for downstream activities such as fish seed production, feed mills, fish processing plants, and other supporting industries. Aquaculture is also currently listed amongst the 16 Agro-food s Entry Point Projects (EPP) of the National Key Economic Area (NKEA). The government aims to double the Agro-food sector s contribution to Gross National Income (GNI) from Malaysian Ringgit (RM) 20.2 billion in the year 2010 to RM49.1 billion by 2020, or an increase of RM28.9 billion.
  • Conference paper

    Assessment of humphead wrasse (Cheilinus undulatus), spawning aggregations and declaration of marine protected area as strategy for enhancement of wild stocks 

    FG Romero & AS Injaki - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Humphead wrasse, known as the Napoleon fish (Cheilinus undulatus), is the largest living member of the family Labridae. It is slow growing but can grow to a maximum size exceeding 2 m and 190 kg. This species was the first commercially important coral reef food fish to be listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II in 2004 because of its vulnerable status and the ongoing threat to its conservation from international trade. Like many coral reef fishes, the humphead wrasse, Cheilinus undulatus, aggregate in reef areas when they spawn and this spawning behaviour makes them highly vulnerable to overfishing. Assessment of the spawning aggregations of this species was conducted in the municipalities of Sibutu and Sitangkai in the province of Tawi-Tawi, Philippines. Key informant interviews (KII) with fishermen, mariculturists, and other stakeholders and focus group discussions (FGD) with local government leaders, Fisheries and Aquatic Resources Management (FARMC) members, mariculturists, and exporters were conducted. Guided by the results of these KII and FGDs, underwater visual census of mameng (local common name for Napoleon wrasse) populations (juvenile and mature) were conducted to document spawning aggregation sites. Since there was no photo-documentation of actual spawning aggregations of mameng in the reef areas, indirect measures were used. Result of the KII and FGD indicated that the Baligtang Reef in Sipangkot and Tando Owak are major sources of spawners. Anecdotal accounts of Bajau fishermen showed that Dungun Dungon, Baligtang reef, Tando Owak and Tugalan are traditional fishing grounds for mameng spawning aggregations. From the length-frequency analysis of mameng caught by hook and line and fish pot in the Baligtang Reef in Sipangkot, the estimated length at maturity of this species was found to be 25-35 cm. There were 134 individuals caught within this size range so they are considered potential spawners. Another indirect proof used was the underwater documentation of juvenile humphead wrasse which were regularly observed and photographed in association with seagrass beds and branching coral reefs in Baligtang Reef in Sipangkot, Sitangkai. Gonadal study also indicated that the mameng caught in this area had mature and ripe gonads but the number of mature fish depends on the season. These were the basis of declaring Spawning Aggregation Sites in Tando Owak and Dungun Dungun in Sibutu and Baligtang Reef, Sipangkot and Tugalan in Sitangkai. These were declared as marine protected areas by ordinance of the municipal Sangguniang Bayan of the two municipalities. Management and enforcement plans have been developed and Bantay Dagat have been trained to protect the spawning aggregations and this strategy aims to protect the wild stocks of humphead wrasse. Protecting the spawners would ensure that there would be enough recruits, prevent recruitment overfishing and enhance the wild stocks.
  • Conference paper

    Social preparations towards community-based approach to stock enhancement in Sagay Marine Reserve, Philippines 

    ND Salayo, RJG Castel, DHM Tormon, RT Barrido, MFJ Nievales & T Azuma - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Stock enhancement involves a set of management approaches which include the release of hatchery-produced aquatic organisms to enhance or restore fisheries. Stock enhancement of various species has a long history in developed countries and it showed that releases have the potential to yield substantial benefits for various fishery stakeholders. While the biological objectives of stock enhancement were often successfully achieved in most of these enhancement initiatives, some results showed that actual social gains in terms of yields, distribution of benefits and institutional sustainability are often inconclusive. The high cost of stocking accrues to the government which means these are supported by public funds. Meanwhile, benefits are dissipated across various stakeholders, some of them did not at all contribute and participate in the stocking program. In such government-initiated and publicly-funded stock enhancement programs, the lack of sense of stewardship among direct fishery stakeholders was observed to have contributed to a vicious cycle of excessive extraction of fishery resources for individual economic benefits.

    Developing countries such as the Philippines would be confronted by budgetary limitations if it has to adopt the stocking strategies applied in developed countries. Thus, with reference to the success of co-management approaches for managing fishery resources in the Philippines, a community-based strategy for enhancement of fishery stocks was explored. SEAFDEC/AQD, with support from the Government of Japan Trust Fund, initiated a community-based approach to stock enhancement in Molocaboc, an island barangay or village within the Sagay Marine Reserve (SMR). The initiative aims to ensure that its goals and strategies are within the social milieu of local stakeholders, i.e. fisherfolks are without financial assets to contribute or pay for the enhancement of the fishery and stock enhancement is often not a priority approach to address fishery resource depletion for most local governments. However, the social assets of fishing communities could be explored to implement stock enhancement. This paper describes the social preparation executed from 2007 to 2011 in order to orient a fishing community such as Molocaboc towards a successful enhancement of overfished species. Initially, the project focused on donkey s ear abalone Haliotis asinina to provide an example for other species. Abalone or kapinan in the vernacular is one of the over-extracted fishery resources in Sagay City. It is one of the high-priced catch among fishers in coastal communities in the Philippines. High buying prices compared with other fish catch motivated small-scale fishers to target abalones and caused its overfishing.
  • Conference paper

    Reaching the poor through aquaculture: The case of technology adoption in rural communities at west central Philippines 

    DB Baticados - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Aquaculture is promoted for food security and poverty alleviation in developing countries. This study examines the socio-economic impact of aquaculture technologies extended to calamitystricken rural communities in Nueva Valencia, Guimaras, representing the marine water fishery and in Dumarao, Capiz, representing the inland freshwater fishery at west central Philippines. The adoption pathway employed in both sites was community-based and participatory. The survey was conducted among cooperators and non-cooperators, randomly selected in equal numbers in two sites with 60 respondents each per site using a pre-tested interview schedule.

    Results showed that aquaculture is an acceptable technology both for cooperators and noncooperators. The venture is a profitable business either done individually or collectively through an association, if managed properly. Milkfish cage culture, however, needs big capital that technology adoption among local fisherfolk (Guimaras) is limited. In contrast, tilapia cage culture enables small farmers/fishers in Dumarao to venture on their own. Dumarao growers were able to innovate using local materials like bamboo poles to make their cages afloat instead of drums or plastic containers as buoys. There were, however, environmental, technological and institutional issues deterring technology adoption in both sites. Climate change and institutional issues were the more prevalent concerns of Dumarao growers. The technological issues like fluctuating market price, cost of feeds, and fry supply were more enunciated in Guimaras.
  • Conference paper

    Stock assessment of christian crabs (Charybdis feriatus, Linnaeus, 1758) in San Miguel bay 

    PM Nieves, NR Olfindo & AM Macale - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Assessment of the status of swimming crab fisheries in San Miguel Bay with focus on Christian or Crucifix crab, Charybdis feriatus, was undertaken from November 2011 to January 2013. An analytical length-based fish stock assessment was employed using the FISAT (version 1.2.2). A total of 7,679 length frequencies (3,612 C. feriatus and 4,067 Portunus pelagicus) were used in the analysis. About 15 and 14 percent gravid females were harvested monthly for both species that may contribute to recruitment overfishing. Population parameters showed exploitation rate (E) for P. pelagicus and C. feriatus exceeded the optimum exploitation (E0.5) implying excessive fishing effort and heavily exploited stocks. Size at maturity of C. feriatus and P. pelagicus in San Miguel Bay is 8.3 cm and 8.5 cm, respectively. Doable options for resources conservation and management strategies are proposed and supported by local government units (LGUs) including the Integrated Fisheries and Aquatic Resource Management Council.
  • Conference paper

    Potential of cowpea (Vigna unguiculata L.) meal as an alternative protein source in diets for giant freshwater prawn (Macrobrachium rosenbergii, de Man 1879) 

    FA Aya, ML Cuvin-Aralar & RM Coloso - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Growth trials were conducted to evaluate cowpea Vigna unguiculata (L.) meal as a potential protein source in diets for giant freshwater prawn, Macrobrachium rosenbergii (de Man 1879), reared in tank and lake-based cages. Five isonitrogenous (approximately 37% crude protein) and isocaloric diets were formulated where fish meal (FM) protein was replaced with 0%, 15%, 30%, 45% and 60% cowpea meal protein (or CP0, CP15, CP30, CP45, and CP60, respectively). Results of an 8-week tank trial showed that the final body weight (FBW), percent weight gain, specific growth rate (SGR) and survival of prawns were not significantly influenced by dietary treatments (P > 0.05), although the highest values, except for survival, were observed with CP45. In a lakebased cage trial that lasted for 16 weeks, prawns fed CP30 and CP45 had significantly higher FBW (13.1 and 14.4 g, respectively) compared to other treatment groups (P < 0.05). SGR (4.52 5.00%/ day), survival rates (53-77%), yield (98.5-116.5 g m-2) and feed conversion ratio (FCR; 2.0-2.7) were not affected by increasing levels of cowpea meal in the diets. Based on these results, cowpea meal can be considered as an alternative protein source in diets for M. rosenbergii.
  • Conference paper

    Perceptions on the effects of maritime activities on the Philippine aquatic ecosystem 

    E Java, T Cruz & IY Hernandez - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Throughout history, humans create an impact on marine ecosystems. May it be positive or negative, such impact is long-term and shapes the overall image of the system. As humanity increases its number, so does the impact it creates. Humanity has relied on the oceans for food, recreation and for various economic opportunities. Overfishing and pollution affects the life in the seas. Advancements in fishing technology, such as tracking technologies and better transportation have reduced fish stocks significantly when matched with non-sustainable practices, such as dredging and trawling. Intentional dumping from sewages, industrial run-off and chemicals has brought about pollution in the seas. Though some pollution may be accidental, like oil spills, it still causes adverse effects to the sea. Excess nutrients coming from fertilizers and intensive farming practices have resulted to what is known as eutrophications. Lastly, changes in the marine environment have led to the introduction of invasive alien species and marine organisms, which are oftentimes difficult to eradicate. Such effects have made researchers rethink of various ways to maintain marine activities while sustaining its ecosystem.

    Through this study, the researchers determined the effects of maritime activities on the population of aquatic creatures directly from the seafarers, and found out their perspectives on how to remedy such effects and sustain the marine ecosystem.

    This research is descriptive in nature, conducted with 100 purposively selected seafarers from Manila. The participants were given a questionnaire that asked for demographics and their perceptions on the effects of maritime activities on the marine ecosystem and ways to provide solutions to minimize or avoid its negative impacts.

    Findings show equal distribution on gender, with majority at the low socioeconomic level (47%) and are Tagalog in ethnicity (56%). The seafarers believe that the maritime activities cause harm on aquatic creatures (43%), limits propagation of aquatic species (36%), makes them prone to mortality (11%) and cause pollution to the atmosphere (10%). Likewise, their perception of minimizing the consequences lies within the proper conditioning of ships and running them in good condition (57%), maintaining a clean place for the marine inhabitants (28%) and creating a good waste-renewal system (15%). The results of the paper is directed towards proper handling and maintenance of the shipping industry and strict supervision for waste management.
  • Conference paper

    Utilization of sensors and SMS technology to remotely maintain the level of dissolved oxygen, salinity and temperature of fishponds 

    RC Munoz, RP Calderon, RC Flores, SC Masangcap & JP Angeles - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Due to the occurrence of fish kills in various fish producing areas in our country, millions of pesos and opportunities for the Filipino people had been put into waste. Bataan Peninsula State University (BPSU) collaborated with the Central Luzon Association of Small-scale Aquaculture to devise strategies to address the said problem and prevent further losses.

    More often than not, a fish kill can be attributed to the low level of dissolved oxygen (DO) in the water, decrease or increase in salinity and sudden increase in temperature, which usually occur after heavy rainfall, flooding or high tide, or high levels of ammonia due to decomposing organic matter and high temperature during summer.

    For these reasons, BPSU researchers tested the use of radio frequencies and installed sensors in different areas of the fishpond at various depths to remotely monitor the levels of DO, salinity and temperature of the water. Once these reach critical levels, the installed system which comes with a specific program, will send an alarm through radio frequencies via Short Messaging Services (SMS) technology on the cellular/mobile phone of the caretaker or the fishpond operator. Upon receiving the alarm, caretakers were able to adjust the levels of dissolved oxygen, salinity and temperature of the water by remotely switching on the air compressor or the electric water pump using their cellular/ mobile phone, thus preventing losses due to fish kills.
  • Conference paper

    Estimation of energy budget of sea cucumber, Holothuria scabra, in integrated multi-trophic aquaculture 

    S Watanabe, M Kodama, ZGA Orozco, JG Sumbing, SRM Novilla & MJH Lebata-Ramos - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Continuous intensification of aquaculture production has brought about environmental issues associated with eutrophication worldwide. Environmental deterioration such as hypoxia and sulfide production due to water and sediment eutrophication originating from aquaculture effluents have been problematic, resulting to sporadic disease outbreaks and fish kills in the Philippines.

    Integrated multi-trophic aquaculture (IMTA) is one of the promising methods for sustainable aquaculture as it also provides a supplementary source of income to the fish farmers. IMTA is a polyculture system that integrates culturing of fed species (e.g. finfish) the main commodity, organic extractive species (e.g. deposit and filter feeding benthos) and inorganic extractive species (e.g. seaweed). In this study, IMTA techniques were established for small-scale coastal fish farmers in the Philippines, with sea cucumber (Holothuria scabra, commonly known as sandfish), as the key species. Sandfish commands the highest price in tropical sea cucumber species.

    Nitrogen (N) budget of sandfish in polyculture with milkfish (Chanos chanos) and Elkhorn sea moss (Kappaphycus alvarezii), both of which are commonly cultured in the Philippines, was estimated using a simple closed box model.

    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. Culture conditions were as follows: 26 g milkfish were cultured in a 5 x 5 x 4 m cage at an average stocking density of 36.7 ind/m3 (i.e. usual practice in the Philippines) with an initial feeding ration of 10% of body weight which was gradually decreased to 4% over time; 10 g sandfish were cultured in a 5 x 5 x 0.3 m cage hung under the milkfish cage to trap particulate N waste (i.e. feces and leftover feed) from milkfish culture at a stocking density of 35 ind/m2; the stocking weight of Elkhorn sea moss line culture was 10 kg. The culture period was 200 days.

    It was estimated that milkfish culture under the above-mentioned schemes cumulatively produced 145 kg of particulate N, and milkfish and sandfish together excreted 60 kg of NH4-N in 200 days of culture. Daily assimilation rate of the particulate N by sandfish ranged from 3.4 to 12.4%, and 6.4% of the particulate N was estimated to be removed by sandfish during the entire 200 days of culture. Daily absorption rate of NH4-N by Elkhorn sea moss increased exponentially with time and reached 100% at 125 days of culture. Cumulative NH4-N from milkfish and sandfish excretion was estimated to be depleted by 162 days of culture.

    For complete utilization of particulate N by sandfish by the end of milkfish culture period (i.e. zero emission), sandfish stocking density should be 805 ind/m2, which is 200 times as high as that in existing sandfish aquaculture operations in countries such as Viet Nam and New Caledonia. The purpose of sandfish culture in IMTA should be emphasized in terms of its economic advantages and not very much on environmental integrity. Cages for sandfish culture should be designed in such a way where only a small fraction of organic matter from milkfish culture (i.e. about 6% in this culture scheme) enters it to avoid sediment quality deterioration and possible death of sandfish. Elkhorn sea moss on the other hand seems very efficient in bioremediation capability.
  • Conference paper

    Post-larval rearing strategies in sandish (Holothuria scabra) culture 

    MF Nievales, R Sibonga & H Figurado - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Various post-larval rearing methods were compared to determine which scheme would give the most yield of newly settled (visible) juvenile stage (> 1mm body length). Five types of postlarval rearing methods were tested: T1- planktonic diatom only (Chaetoceros calcitrans, Cc), T2-benthic diatom Navicula (Nsp) as biofilm and concentrate, T3- Navicula as biofilm + Cc, T4Spirulina as paste on settling plate + Cc, and T5- Spirulina (Sp) as paste on settling plates + Nsp concentrate. An experiment was conducted in small (3-li) aquaria using a cohort of Day 14 (postfertilization) sandfish larvae. Simultaneously, three of the 5 post-larval rearing methods (i.e. T2, T3 and T4) were done in medium scale (30-li) aquaria to determine how a conventional method (T2) employed in a pilot sea cucumber hatchery in Central Philippines compared with method observed in Viet Nam (T3) or with a hybrid method (T4). Visible post-settled juveniles were counted weekly for the next three weeks and expressed as percentage yield. After three days of rearing, transparent but visible early settled juveniles were observed. Mean percentage (%) juvenile yield in week 1 was highest in T1 (Cc only)(17% + 1.3) followed by T3 (Sp + Cc) (14% + 1.6) in a 3 li scale. Yield increased and peaked in week 2 especially for rearing methods with Nsp while those without (e.g T1 and T2) declined dramatically by week 3. In the 30-li scale, the highest mean yield was consistent with T5 (Nsp + Cc) until Week 3 (12% + 11.2). The mean juvenile yield on the 2nd and 3rd week were better than the 2% average for this stage or the 2.5% benchmark based on experiences in the Philippines and Viet Nam as indicated in published references.
  • Conference paper

    Milkish: new choice for aquaculture in Thailand 

    P Kosawatpat - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Milkfish is an economically important fish cultured in many countries in Asia. In Thailand, milkfish culture has not been given much attention and has not as been developed as in the other Asian countries because in the past the farmers prefer to grow shrimps and other high value fishes. Nowadays, environmental changes and degradation can affect water resources as well as the important aquaculture species that thrive in them hence the Thai Department of Fisheries recognizes the importance of developing aquaculture that is environment-friendly. This includes milkfish in particular because milkfish meat tastes good, easy to manage on farm, grows rapidly and can be grown in sea water, brackish or even freshwater. Milkfish farming is a low cost operation because milkfish feed mainly on algae and organic matter and these are natural food produced from other types of aquaculture activities. Milkfish can therefore be co-cultured with other species and are capable of reducing the amount of organic material from the process of aquaculture before entering the environment. In 2002, milkfish was first bred successfully through hormone injection and later broodstock mated naturally in Thailand. At present, production of the 1-inch milkfish has reached 1,000,000 per year. The culture sites are in the southern and eastern parts of the country, in brackish and salty areas. Culture methods are either monoculture or polyculture with other species such as shrimp, mussel etc. Milkfish culture in reservoirs last from 6 to 12 months when fish size is about 500 g or two pieces to a kg. and the price is about 50 baht/ kg. On the other hand, milkfish that are 600-1,000 g can sell at 65-90 baht/kg. Apart from culture, processing as well as marketing promotion of milkfish has also started in Thailand. Milkfish processing training is being conducted at least 2 times a year. As for the marketing initiatives, there is a move for the milkfish to be declared the symbol of Prachuap Khiri Khan Province since it was here that the fish was first found naturally in Thailand. This, apart from the plan to promote milkfish in the festivals throughout the country. Although found promising, some problems in the Thai milkfish industry are also recognized. Such issues notwithstanding, the Thai Department of Fisheries is coming up with guidelines for milkfish aquaculture as it is optimistic that this commodity shall open the doors to a new alternative industry in Thailand.
  • Conference paper

    Distribution and abundance of hard clam shells Meretrix meretrix along the coastal areas of Panguil bay, Lanao del Norte, Philippines 

    CQ Jumawan, RB Palma & RO Sia - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Meretrix meretrix is believed to be abundant in Panguil Bay and in the absence of relevant fishery statistics, it is useful to quantify their biomass with a view to determining their fishery potential. This study aims to monitor the gonadal development, identify the associated macrofauna and determine the distribution and abundance of hard clam shells M. meretrix along the coastline of four municipalities of Lanao del Norte at Panguil Bay. Four sampling sites were selected and established to achieve and relate some generalities using the transect-quadrat method. Clams were counted, measured and identified. Physicochemical parameters were also noted every sampling. M. meretrix was found to be most abundant in Raw-an Pt. Baroy (28-542 pcs./m2) followed by Mayao, Lala (0.3-26 pcs/m2). M. meretrix at Aloha Tubod occurred in low densities (0.1-4 pcs/m2). No hard clam shell was found in Taguitic, Kapatagan. Mean length differed significantly at the three locations. The coastal area of Mayao, Lala, had the highest diversity (H' = 4.236737) in terms of shell species identified and recorded during the twelve months sampling period. Most of the shells dissected were sexually immature with male shellfishes being more predominant than females. Differences in distribution, density and length size of hard clam shells were compared in this study at four locations. Anthropogenic causes e.g. exploitation as well as environmental parameters such as salinity levels and sediment quality are suggested to be the main cause of the variation. These results will be used as baseline information to properly manage hard clam shell resources in Panguil Bay.
  • Conference paper

    Potential genetic impacts of hatchery-based resource enhancement 

    ZU Basiao - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The global population according to the United States Census Bureau has reached 7 billion as of October 2013. The continuous growth in human population will continue to put tremendous pressure on food production. The demand for fish as source of good protein is no exception. In 2011 total capture fisheries supplied 90.4 million tons of food and total aquaculture provided 63.6 million tons. While aquaculture production has increased dramatically, more than 50% of fishery production still depends on capture fisheries. Overexploitation of wild fish stocks has become one of the biggest problems in global fisheries. Stock enhancement has become a potential viable strategy for marine fisheries in danger of collapse. With the tremendous progress made in the breeding and larval rearing techniques of marine species, hatchery-based stock enhancement is now operated in many stock enhancement programs. However, many questions are raised in the use of hatchery-reared fish in stock enhancement. This paper will discuss genetic considerations in stock enhancement in developing countries.
  • Conference paper

    Good aquaculture practices (GAqP): setting directions for harmonized regional standards - the Philippine experience 

    MF Matubang & NA Lopez - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    A milestone process on how Good Aquaculture Practices (GAqP) emanates in Philippine aquaculture and its integration to the ASEAN harmonized standardization efforts is discussed in the paper. The management model, value chain and draft Philippine National Standard of the GAqP code are presented and evaluated as to its impact to trade and marketing, socioeconomic considerations, food safety and technology.
  • Conference paper

    Stock enhancement? Why bother 

    J Ingles - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    There are two approaches to resource enhancement of depleted wild fish stocks: through stock enhancement where aquaculture science plays a central role, or through improved management of fish stocks. This paper presents an argument that despite major advances in stock enhancement technologies (tagging, genetic mapping, numerical modeling techniques), major hurdles in policy framework, science and information gaps, risk mitigation protocols and capacity gap remain. These factors are associated with high and recurring cost that requires medium to long-term solutions that ultimately, improving management and governance to recover depleted stocks will still be the best option available.
  • Conference paper

    Shrimp metabolism: The roles of lactate dehydrogenase (c31), glycogen phosphorylase (c34) and protein kinase (PK) as revealed by RNA interference 

    MVR Tare, H Kondo, I Hirono & MBB Maningas - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Energy metabolism is well-studied in vertebrate systems, providing insights on the genes and mechanisms involved in different pathways necessary for the survival of an organism. Yet, such studies are still lacking in invertebrate systems much more in shrimp. An earlier study has showed several contigs from the black tiger shrimp to be homologous to white spot syndrome virus (WSSV), a devastating pathogen in shrimp, including contig 31-WSSVORF82 (c31) and contig 34-WSSVORF21 (c34). This study aims to unveil the roles of three genes: c31, c34 and protein kinase (PK) in the shrimp system and its possible role in WSSV-infection. Rapid amplification of cDNA ends-polymerase chain reaction or RACE-PCR was used to obtain the full-length sequence of c31 and c34, followed by in vivo gene silencing using RNAi technology, and intramuscularly injecting dsRNA to WSSVchallenged Macrobrachium rosenbergii and Penaeus (Marsupenaeus) japonicus. Gene expression followed for healthy shrimps and dsRNA-treated shrimps.

    Mrc31 was revealed to be the enzyme lactase dehydrogenase (LDH), commonly released during tissue damage and is a marker for disease. The most parsimonious tree pictured Mrc31 to be sister clades to LDH of other shrimp species, Penaeus monodon and P. vannamei, supported with 100% and 72% bootstrap values, respectively. Mrc34 was highly homologous to the glycogen phosphorylase (GP) enzymes of other organisms including that of another shrimp, M. japonicus, bearing a bootstrap value of 99%. For PK, phylogenetic analysis revealed that the three open reading frames (ORFs) from P. monodon, M. rosenbergii and P. japonicus have 30% homology to WSSV-PK supported by a 98% bootstrap value. Mortality data from dsRNA-treated and WSSV-infected shrimps showed that treatment with dsRNA-LDH, GP and PK had significantly higher survival rates compared to that of the controls, Phosphate Buffered Saline (PBS) and Green Fluorescent Protein (GFP). Silencing the three genes in the shrimp has rendered some protective effect against the virus. Gene expression showed that all three genes are present in immune-related organs such as the gills, hepatopancreas and hemocyte. This study is the first to report the possible identities and functions of contigs 31, 34 and PK providing valuable data on the shrimp's genome.
  • Conference paper

    Marine fish hatchery: developments and future trends 

    CL Marte & JD Toledo - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The basic procedures for producing marine fish fry in hatcheries developed for milkfish fry production nearly 3 decades ago are the basis of fry production systems for all other marine fish species that are now reared in hatcheries in the Philippines and other Southeast Asian countries. These include large-scale microalgae production in outdoor tanks, feeding of appropriate sized rotifer grown on microalgae such as Nannochlorum during the first feeding phase, and shifting to larger prey such as Artemia towards the latter stages of production.

    In recent years, the increasing demand for high-value species such as groupers, sea bass, red snapper, and pompano in both local and export markets has encouraged a number of hatcheries to produce fry to supply the requirements of fish cage farmers. Techniques are modified using information from research institutions and multi-national firms active in developing products and equipment to improve commercial production of these species. Larval feeds of appropriate sizes, forms and presentation for various larval stages incorporating essential nutrients, micronutrients, and feed stimulants are now available in the market. Diseases in marine fish hatcheries have become common occurrences such that various chemotherapeutants, vaccines, and immunostimulants are now available and increasingly being applied in fish hatcheries. Technological developments in hatchery systems, such as the use of recirculating systems, water pretreatment protocols (ozonation, mircrofiltration, UV light treatment) are also increasingly being adopted by commercial establishments.

    A critical link between fry production and production of marketable fish is fingerling/ juvenile production in nurseries. Fry are commonly grown in brackishwater fishponds to appropriate size for stocking in fish cages. Methods to improve growth through proper feeding and nutrition, eliminate or reduce disease occurrence and parasite infestation, reduce cannibalism in cannibalistic species such as sea bass, grouper and snappers are active areas of research. Nursery production is integrated with fry production in large commercial facilities but is also done by small-scale fish farmers who have access to fry either from the wild or hatcheries. Commercial hatcheries adopt fingerling production from well-studied species in developed countries. Smallscale farmers however still rely on zooplanktons collected from the wild such as copepods, Moina, mysids, and trash fish as feed. Production is dependent on availability of feed sources and susceptibility to pathogens and parasites that come with the feed. It can also be erratic since smallscale farms are vulnerable to changes in climate and weather conditions.

    Further technological advancement in marine fish hatcheries will increasingly be led by commercial establishments and industries developing equipment like photobioreactor for microalgae to produce algal paste, or methods to develop intensive systems for rotifer culture. Research institutions will however need to support the needs of the small-scale farmers and hatchery operators who may not be able to apply costly products from these companies by developing innovative simple techniques that can improve culture systems such as producing fry and fingerlings in mesocosm pond system, appropriate use of probiotics as water stabilizer, and production of zooplankton in ponds.
  • Conference paper

    Rapid adaptation to a new environment: is it reversible? 

    H Araki - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Accumulating evidence suggests rapid adaptation of fish populations when they are exposed to artificial hatchery environments. However, little is known if rapidly-adapted populations can readapt to their original, natural environment at the same rate. Here, I review recent studies on salmonid fish that address this issue. They indeed suggest rapid adaptation of hatchery populations, in which reproductive fitness under a natural environment became much lower than that in the wild population after only 1-2 generations of captive breeding. However, the reproductive fitness did not recover after one generation of natural rearing, implying that rapid adaptation to a new environment was not reversible at the same rate. I discuss potential consequences of the irreversible fitness reduction in extensively stocked fish species. Understanding the mechanism behind the irreversible rapid adaptation in fish populations will help us figure out a better, nature-friendly, and hence sustainable means of hatchery operations for human welfare.

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