96 research outputs found

    Cultivation of tropical red seaweeds in the BIMP-EAGA region

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    The Brunei–Indonesia–Malaysia–Philippines East Asia Growth Area (BIMP-EAGA) is located within the Coral Triangle, known to have the world’s richest biodiversity in marine flora and fauna. This region lies within the 10° N and 10° S of the Equator where natural populations of both Kappaphycus and Eucheuma grow luxuriantly and abundantly. It is in this same region where commercial cultivation of Kappaphycus and Eucheuma began in the Philippines around the mid-1960s. Commercial farming of Kappaphycus (which was originally called Eucheuma) was successful in the Philippines from the early 1970s, after which the technology was transferred to Indonesia and Malaysia in the late 1970s. No seaweed cultivation has been reported in Brunei. At present, carrageenophytes are cultivated in sub-tropical to tropical countries circumferentially around the globe within the 10° N and S of the Equator. However, their combined production is still low as compared to Indonesia, the Philippines, and Malaysia. Notably, few improvements in farming techniques have been made since its first introduction. Some of the major improvements were the introduction of deep-water farming using hanging long lines, multiple rafts, and spider webs in the Philippines; the use of short and long ‘loops’, instead of plastic ‘tie-tie’ in Indonesia; and mechanization in harvesting and use of solar “greenhouse” drying in Malaysia. Commercial cultivation of tropical red seaweeds in the BIMP-EAGA region is dominated by Kappaphycus and Eucheuma (carrageenophytes) and Gracilaria (agarophytes) and the area became the major region for the production of carageenophytes and agarophytes globally. In particular, Indonesia is a major center for the production of Gracilaria. There is an increasing demand for other agarophytes / carrageenophytes in the international market such as Gelidium spp., Pterocladia spp., Porphyroglossum sp., and Ptilophora sp. for paper and ethanol production in Indonesia and Malaysia, and Halymenia for phycoerythrin pigments in the Philippines currently pursued in an experimental stage. A summary of the present status, problems, sustainability, and challenges for the cultivation of tropical red seaweeds in the BIMP-EAGA region are discussed in this paper

    Genetic and morphological analyses of Gracilaria firma and G. changii (Gracilariaceae, Rhodophyta), the commercially important agarophytes in western Pacific

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    Many studies classifying Gracilaria species for the exploitation of agarophytes and the development of the agar industry were conducted before the prevalence of molecular tools, resulting in the description of many species based solely on their morphology. Gracilaria firma and G. changii are among the commercially important agarophytes from the western Pacific; both feature branches with basal constrictions that taper toward acute apices. In this study, we contrasted the morpho-anatomical circumscriptions of the two traditionally described species with molecular data from samples that included representatives of G. changii collected from its type locality. Concerted molecular analyses using the rbcL and cox1 gene sequences, coupled with morphological observations of the collections from the western Pacific, revealed no inherent differences to support the treatment of the two entities as distinct taxa. We propose merging G. changii (a later synonym) into G. firma and recognize G. firma based on thallus branches with abrupt basal constrictions that gradually taper toward acute (or sometimes broken) apices, cystocarps consisting of small gonimoblast cells and inconspicuous multinucleate tubular nutritive cells issuing from gonimoblasts extending into the inner pericarp at the cystocarp floor, as well as deep spermatangial conceptacles of the verrucosatype. The validation of specimens under different names as a single genetic species is useful to allow communication and knowledge transfer among groups from different fields. This study also revealed considerably low number of haplotypes and nucleotide diversity with apparent phylogeographic patterns for G. firma in the region. Populations from the Philippines and Taiwan were divergent from each other as well as from the populations from Malaysia, Thailand, Singapore and Vietnam. Establishment of baseline data on the genetic diversity of this commercially important agarophyte is relevant in the context of cultivation, as limited genetic diversity may jeopardize the potential for its genetic improvement over time

    The farming of the seaweed Kappaphycus

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    A 24-page manual that introduces the carrageenan-producing seaweed Kappaphycus whose culture has spread from Jolo in Mindanao to at least 14 sites in the Visayas and Luzon. Four culture methods are presented: fixed off-bottom, raft long-line (single or multiple), hanging long line, and polyculture of seaweeds with carnivorous fishes.Englis

    Pag-aalaga ng halamang-dagat na Kappaphycus

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    A 24-page manual that introduces the carrageenan-producing seaweed Kappaphycus whose culture has spread from Jolo in Mindanao to at least 14 sites in the Visayas and Luzon. Four culture methods are presented: fixed off-bottom, raft long-line (single or multiple), hanging long line, and polyculture of seaweeds with carnivorous fishes.Filipin

    Seaweeds of Panay

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    This practical book on the seaweeds of Panay, Philippines, acquaints and provides information to members of the academe and research institutions, policy makers, fishermen and businessmen regarding the taxonomy, distribution, ecology and economic importance of these resources. It consists of 4 major parts: (1) Introduction, which reviews the literature, habitat, distribution, morphological structure and reproduction; 2) Classification, which describes the classes to which the seaweeds generally belong; 3) Collection and preservation, which explains the procedure used in treatment of specimens; and, 4) Taxonomic list. A glossary is included, covering technical terms used. All species listed and described in this book are macrobenthic and were collected in Panay and Guimaras Islands.Preface -- Introduction -- Classification -- Collection and preservation -- Taxonomic list: Class Chlorophyceae -- Class Phaeophyceae -- Class Rhodophyceae -- Glossary -- References -- Acknowledgement.1st Ed

    The Economics of Kappaphycus Seaweed Cultivation in Developing Countries: A Comparative Analysis of Farming Systems

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    The farming of the red seaweed Kappaphycus alvarezii and related species as raw material for the hydrocolloid carrageenan rapidly spread from the Philippines in the late 1960s to Indonesia, Tanzania, and other tropical countries around the world. Although numerous studies have documented positive socioeconomic impacts for seaweed farming, factors such as diseases and distance to export markets have led to an uneven development of the industry. Using standard budgeting techniques, this study adapted production and market data from a FAO-led global review of seaweed farming to develop comparative enterprise budgets for eight farming systems in six countries (Indonesia, the Philippines, Tanzania, India, Solomon Islands, and Mexico). Although the basic technology package is the same across countries, the study revealed large differences in the economic performance of systems due to wide variations in farm prices and the scale of operations. Although seaweed farming is a suitable activity for small-scale producers, a minimum of 2,000m of cultures lines are still necessary to ensure adequate economic returns. Greater farming plots may be needed if farm prices are well below the average farm prices paid in Indonesia and the Philippines. Policy recommendations are made to improve the economic potential of underperforming systems

    Seaweed research at SEAFDEC/AQD

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    Seaweed: Gracilaria

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    This paper reviews the studies on Gracilaria/Gracilariopsis conducted from 1988 to 1991 by the Aquaculture Department, Southeast Asian Fisheries Development Center. It includes 114 species of macrobenthic algae collected in Panay, the nomenclature of Gracilariopsis heteroclada previously described as Gracilaria sp., and the biology, ecology, and farming systems of Gracilariopsis. Agar quality of the different species of Gracilaria and the effect of seasonal variation on the quality and quantity of agar produced from Gracilariopsis heteroclada were also studied

    Research on seaweeds and mollusks

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    Research on seaweeds focused on the carrageenan-producing Kappaphycus alvarezii and the agar-producing Gracilaria spp. Growth of K. alvarezii was better on horizontal lines than on vertical or cluster lines from bamboo rafts. All morphotypes (brown green, and red) grew faster at 50 cm than at 100 cm below the water surface, but the green morphotype showed better carrageenan properties. A socioeconomic survey of K. alvarezii farming in Panagatan Cays, Antique revealed that a farmer has an average annual production of 3 tons/ha (dry) with the fixed bottom and hanging longline methods. Three species of Gracilaria in natural beds in lloilo showed monthly variations in biomass and agar quality; G. heteroclada had the highest biomass and gel strength. When this species was grown in tanks, growth and agar sulfate content were influenced by the interaction of light, salinity, and nutrients. Enriched and unenriched stocks of G. heteroclada differed in agar quality. When G. heteroclada was grown with the tiger shrimp Penaeus monodon in extensive ponds, the highest growth rate and production were obtained at the seaweed stocking density of 250 g/m2; this was in November when average water temperature, transparency, and salinity were low. Salinity tolerance varies among Gracilaria species.Oyster (Crassostrea iredalei) and mussel (Perna viridis) farming in Western Visayas were assessed in 1992 in terms of the culture methods, socioeconomics, marketing, and profitability. A more localized survey of oyster and mussel fanning was conducted through rapid rural appraisal in two coastal towns in 1993. A farmer-participatory study followed in 1994 for the culture of oysters, mussels, seaweeds, and rabbitfishes in a river mouth in Dumangas, lloilo. Green mussel, brown mussel (Modiolus metcalfei), and seaweeds transplanted to Dumangas from Capiz have reproduced. In another study, the green mussel was tested as a biological filter in tiger shrimp ponds; shrimps stocked with mussels grew better than those without. A nationwide survey on the Placuna placenta fishery in 1993 showed 27 remaining 'kapis' beds; many others have been depleted due to excessive gathering, pollution, siltation, and trawling. Broodstocks are being developed to produce 'kapis' seed for grow-out and restocking. For the first time at AQD, adult donkey-ear abalone Haliotis asinina from the wild spawned naturally in laboratory tanks. Juvenile abalones can be successfully grown on Gracilaria or abalone diet

    Seaweed research at SEAFDEC Aquaculture Department

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    Seaweed research at the Aquaculture Department of SEAFDEC focuses mainly on 2 genera of agarophytes (Gracilaria and Gracilariopsis) and carrageenophytes (Eucheuma and Kappaphycus). From 1988 to 1998, research works were mainly on Gracilaria and Gracilariopsis along these areas: (1) refinement of culture technique, (2) basic biology, production ecology, and corp management, (3) product utilization, (4) screening and characterization of natural products, and (5) economics of farming system. Four years ago, the Seaweed Program of the Department re-focused its thrust on Advanced Aquaculture Technologies (Biotechnology) to include also Eucheuma and Kappaphycus in answer to the needs of the industry. This paper briefly describes the highlights of the different studies done on biotechnology
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