Now showing items 1-7 of 7

    • Conference paper

      Development of integrated multi-trophic aquaculture using sea cucumber 

      S Watanabe, M Kodama, JG Sumbing & MJH Lebata-Ramos - 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-168
      In 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.
    • Book

      Field guide to mangrove identification and community structure analysis 

      MJH Lebata-Ramos - 2013 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The mangrove field guide is a 32-page field guide with a one page introduction on mangroves, followed by a key to mangrove genera and species (with colored pictures of the whole plant and plant parts), then a definition of important terms used in the key, species code for use during mangrove community structure, instructions on how to conduct mangrove community structure analysis plus the formulas for the different indices (relative density, dominance, frequency; importance value and species diversity) and a sample data sheet. The guide, measuring 9 cm x 14 cm, is printed on PVC material hence it can get wet, soaked or be left in the water for days.
    • Article

      The first record of a cupped oyster species Crassostrea dianbaiensis in the waters of Japan 

      M Sekino, H Ishikawa, A Fujiwara, EFC Doyola-Solis, MJH Lebata-Ramos & H Yamashita - Fisheries Science, 2015 - Springer Verlag
      With a combination of our mitochondrial and nuclear DNA data, we evidenced the occurrence of a Crassostrea oyster hitherto unrecognized in Japan. This species, C. dianbaiensis (named Sumizome-gaki in Japanese), was very recently described as a new “tropical” oyster, although we located it in a temperate water zone (southwestern coast of Shikoku Island, Japan). Our specimens bore a morphological resemblance to the slipper cupped oyster C. bilineata (syn. C. iredalei), consistent with their close phylogenetic relationship. Some of the shell characteristics represented in the original species description were not applicable to our specimens, especially in terms of the pattern of their inner-shell coloration. Our novel finding of C. dianbaiensis in Japan updated the taxon list of Japanese Crassostrea species.
    • Conference paper

      Fishery resource enhancement: An overview of the current situation and issues in the southeast Asian region 

      MJH Lebata-Ramos & EF Doyola-Solis - 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 Center
      The 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.
    • Article

      Growth pattern of the tropical sea cucumber, Holothuria scabra, under captivity 

      S Watanabe, J Sumbing & MJH Lebata-Ramos - Japan Agricultural Research Quarterly, 2014 - Ministry of Tropical Agricultural Research Centre
      The growth of the juvenile sea cucumber, Holothuria scabra, was studied under captivity to elucidate the growth variation pattern and determine the best-fit growth model to estimate age- and size-specific growth rates. Individual growth was extremely variable, with some individuals below the mean initial weight and some expanding their original body length (L) and weight (W) by up to 6.4 and 156 times, respectively; during 84 days of culture starting at 127 days of age. Some of the smallest individuals showed a higher condition factor than larger individuals in the presence of ample food, indicating that lack of food may not be the only impediment to growth. Among the three growth models compared (von Bertalanffy, Gompertz and logistic), the Gompertz model was considered optimal to express H. scabra growth; both in L and W. The age- and size-specific daily growth rate for L and W up to 365 days of age, as estimated by the Gompertz model, had a range of two and nine orders of magnitude in L (0.035 – 0.96 mm/day) and W (3.4 × 10-7 – 3.5 g/day), respectively. Use of the Gompertz model over the linear model, which tends to overestimate growth rates, is encouraged to estimate the growth of H. scabra more accurately.
    • Article

      Metabolic rate characteristics and sediment cleaning potential of the tropical sea cucumber Holothuria scabra 

      M Kodama, JG Sumbing, MJH Lebata-Ramos & S Watanabe - Japan Agricultural Research Quarterly, 2015 - Ministry of Tropical Agricultural Research Centre
      The oxygen consumption rate (OCR) and ammonium excretion rate (AER) of a tropical sea cucumber, Holothuria scabra, were determined in laboratory experiments. OCR and AER exhibited a significant negative correlation to body weight (BW), expressed as a power function of BW: OCR = 0.09 × BW−0.58 (mgO2/g/h, r2=0.89, n=15) and AER = 0.38 × BW−0.19 (μmolN/g/h, r2=0.54, n=15). These values were comparable to those in previous studies on other sea cucumber species. The OCR of shrimp tank sediment was reduced to less than half (4.5 ± 0.3 to 1.0 ± 0.1 mgO2/gdry/h) by the ingestion and excretion process of H. scabra. Acid volatile sulfide (AVS-S) concentration was also decreased to less than half (0.67 to 0.31 mgS/mgdry); despite the low reduction rates of organic carbon and nitrogen contents (0.19 to 0.14 mgC/mgdry and 0.022 to 0.019 mgN/mgdry, respectively). These results suggest that components in the sediment with high oxygen consumption potential were removed by H. scabra. These findings also provide fundamental information with which to evaluate the quantitative role of H. scabra in polyculture with shrimp.
    • Conference paper

      SEAFDEC/AQD stock enhancement initiatives: Release strategies established 

      MJH Lebata-Ramos, EF Doyola-Solis, R Sibonga, JB Abroguena, A Santillan & M Dimzon - 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 Center
      SEAFDEC/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.