U Win Htin
Research and Development Section
Planning and Research Division
Ministry of Livestock Breeding and Fisheries
Myanmar, having a long coast line of 2,832 km with many rivers flowing into the extended and large continental shelf of 228,781 sq.km, is rich in natural fishery resources. These resources include not only fin and shell fishes but also seaweeds which are commonly found washed up the beaches. Myanmar belongs to three coastal shelves namely Rakhine, Ayeyarwady and Tanintharyi.
Statistics on seaweed production are not readily available, but the Marine Biological Department of Moulmein University and Myanmar Foodstuff Industries estimate that at least 1,500 tons of dried raw seaweed are produced in Myanmar each year.
The economic importance of seaweed in Myanmar has been studied by Kyi Win (1968) and it has given a good basis for further expansion on utilization of the resources. Catenella nipae culture experiments have also been carried out by Kyi Shwe (1972) at Kyaikhame. Min Thein and et al., (1974) studied the culture as well as utilization aspects of Gracilaria edulis at Setse near Mawlamyaing. The carrageenan extracted from Hypnea was produced by Diamond Aerated Water Factory in 1976. Powder and stick forms of carrageenan from Hypnea were produced by some at home industry level in late 1950s. In 1977, based on the results gained from the experiments in Mon State, pilot scale culture experiments were carried out in Thantwe township, Rakhine State. These experiments were finished and the results submitted in 1979 by Lay Maung, Saw New Year and Aye Kyaw. Their report mentioned the environmental condition, culture methods and possibility of commercial production. Myo Thant Tin (1979) installed a factory to produce instant carrageenan from Hypnea and agar from Gracilaria in Thandwe. In 1984, Min Thein processed Myanmar's edible seaweed Enteromorpha, Catenella, and Sargassum as Japanese nori. Nutritional features, processing methods for assorted dishes and comparisons with Japanese nori were presented by him. Pilot scale culture of seaweed Gracilaria edulis and its economics were studied by Saw New Year, Aye Kyaw and Nyan Taw in 1988.
3. Current Status
There are ten genera of red algae, four of brown ones and eight of green ones in Myanmar. Seaweed occurrences in different coastal areas of the country are shown in Table 1. All of the genera shown in Table 1 are found in the three coastal areas except for Catenella and Porphyra which are found only in Rakhine area.
Statistics on seaweed production are not readily available, but based on a year's domestic consumption, it may be estimated that at least 1,500 tons of dried raw seaweed (15,000 tons in wet state) are produced annually. Production comes mainly from Enteromorpha, Catenella, Sargassum and Hypnea. Production by genus is shown in Table 2 below:
|Sr. No.||Genus||Production in tons|
(b) Culture System
Out of many species of seaweed Gracilaria edulis is utilized in culture. Two types of culture systems are practiced i.e. on open sea and in ponds.
Open Sea Culture
Open sea culture was carried out at Maung Shwe Lay Bay in Rakhine state, using vertical constant length long line floating system (Fig. 1). Total length of one net line system was approximately 50 m. In one net long line system, 50 floats were used. The diameter of the rope was between 8–12 mm. The concrete blocks weighing 16 kg or iron anchor, were used to anchor the net line system. Nylon nets woven 18-ply and measuring 5.0×10.0 m with a net aperture of 13 cm were used. In this system, a total of 10 nets were attached to one line, and for the experiment, from 30 to 90 long lines were used.
Pond culture was carried out using four bamboo poles fixed to the bottom in the shape of a square. The nets were attached to these poles so that the net also assumed a square shape (Fig. 2). The nets were 0.3 metres above the bottom. Two 0.2 ha ponds situated by the beach were used.
Initially, G. edulis seed plants for the culture were collected from Mawtin Point, Ngaputaw township and transported to the site within 36 hours. Recently, seed plants of the same species have been collected from Andrew Bay only about 7 miles from Maung Shwe Lay Bay. The seed plants were collected fortnightly during the season lasting from February to April and carried in baskets and planted immediately on arrival at the culture site.
Figure 1. Vertical long-line floating net system.
Figure 2. Horizontal net system.
Planting Seed Plants
The seed plants collected from various parts of the coast were immediately cut into 5–7 cm fragments and tied to the cross-sections of the nets with thin plastic strings (Fig. 3). This seeding was done during the month of April.
Cultivation and Harvest
The seaweeds were harvested about 30 days after seeding, after which harvesting was done every 30 days. At every harvest, one third of the plant was left as seed plant. Final harvest was done in September. Harvesting was done by hand. During the cultivation period, net line systems and plants had to be maintained regularly to minimize weather-influenced damage and that caused by marine animals such as fish, crab and molluscs. Harvested seaweeds were washed and cleaned. Cleaned seaweeds were then dried on bamboo screens in the sun for a day or more depending on the weather condition.
The temperature of Maung Shwe Lay Bay ranged from 28.3 °C through 31.6 °C. High water temperature was observed during April and May. Water salinity ranged from 19.2 ppt to 30.4 ppt. Low salinity was observed from mid-May to August probably due to monsoon rains (Fig. 4).
With the open sea culture method, after the planting of seed plants onto the culture nets, the plants flourished and reached full bloom in July and August. However, in mid-September, signs of deterioration could be noted. The fronds finally became pale and weak in October (Fig. 5). From then on, the growth was stunted until January.
In the present study, G. edulis was found to change into sexual plants by the appearance of spores which settled down and germinated on the culture nets. These germinated spores were found to grow to harvestable size.
Seaweed G. edulis harvested to date from vertical long-line at constant depth, with 50–90 net lines, produce over 13,454 kg (Table 3). With this method, seaweeds were harvested after 30 days from seed planting. In one season from the same net, seaweeds were harvested 5 times (Table 4). Generally, from one long-line net, between 120 and 360 kg could be harvested in one season.
Figure 3. Seed plants fixed on the culture net.
Figure 4. Seasonal variation of salinity and temperature at Maung Shwe Bay.
Figure 5. Seasonal cycle of Gracilaria edulis at Maung Shwe Bay.
|Year||No. of net line system||Wet Weight|
|No. of harvests||Total one season|
A major problem was inclement weather. Due to choppy waters, vertical long-line nets were cast off from their moorings with loss of operation materials. In some cases, seaweeds were washed away from the nets. Some seaweed lost this way were recovered from the beaches in the vicinity of the experimental site. Other problems came from predators such as fish, crab, amphipods, polychaetes, isopods, copepods, gastropods and bivalves, and competitors such as blue green algae, Padina, Acanthophora, and filamentous algae (Nostoc, Microcoleus, Hydrozoans) which in some cases totally engulfed the seaweeds.
With pond culture, production to date from two half-hectare ponds was 2,600 kg in wet condition. Production per net in terms of square meters was approximately the same as that from open sea culture. Compared to open sea culture, the materials and labour used were much less in the pond culture although the high initial investment in pond construction might be a constraint.
As mentioned before, seaweeds are processed in Myanmar into agar, carrageenan and alginates. Agar is processed from Gracilaria and Gelidium, and sold in strips and powder form. Agar is sometimes marketed as jellies. As a traditional Myanmar dessert, instant agar processed mainly from Gracilaria is a main dish after meals. Some home industries and the government-owned Diamond Aerated Water Factory produce dessert jellies from agar.
People's Toilet Industries under the supervision of Myanmar Foodstuff Industries use carrageenan from Hypnea to manufacture non-food products such as toothpaste, cosmetics and solid air fresheners. Myanmar Textile Industries also use alginates for sizing and printing.
Catenella nipae and Sargassum are popular as ingredients for salad dressing. Myanmar indigenous medical practitioners indicate that a salad dressing from the above seaweed can cure goiter.
The form and extent of seaweed utilization in Myanmar are shown in Table 5.
There occur in Myanmar ten genera of red algae, four of brown ones and eight of green ones. Except for Catenella and Porphyra which occur in Rakhine area, other species are distributed throughout the entire coast region. Estimates based on demand and uses by government-owned factories indicate that at least 1,500 tons of dried raw seaweed is produced annually.
Due to changes in weather conditions, production of natural seaweed is unpredictable, which indicates an advantage in adopting the pond culture method. Accordingly, research on culturable species, culture method and market should be carried out.
From the experiences gained by local researchers so far, it is safe to say that pond culture is more advantageous than open sea culture. For the latter, a period lasting from April through October is a good season with the remaining portion of the year to be treated as a resting period. During this resting period, the sea is calm without any up-welling resulting in deficiency of nutrients. In the same period, small fishes would graze on the seaweeds. This is when pond culture method is needed to fill up the time gap that would otherwise be wasted.
More experiments should be carried out to find more uses of the seaweed species which are currently not commercially utilized. Experiments should also be done on culture techniques so that the ones that are better suited to the condition in the country would be obtained. Regarding processing, modern technology and equipment should be searched for in countries where the technology of seaweed processing is advanced.
|Acanthophora||x||-||xx||- Human food and carrageenan|
|Catenella||x||-||xx||- Human food|
|Gelidium||x||-||xxx||- Funorin and human food|
|Gracilaria||-||x||xxx||- Funorin, human food and agar|
|Halymenia||x||-||x||- Human food|
|Hypnea||x||-||xxx||- Human food and agar|
|Laurencia||x||-||x||- Human food|
|Liagora||x||-||x||- Human food|
|Porphyra||x||-||xxx||- Human food|
|Scinaria||x||-||x||- Human food|
|Hydroclathrus||x||-||xx||- Human food, fodder, manure alginate and medicinal|
|Padina||x||-||x||- Human food|
|Sargassum||x||-||xx||- Fodder, manure alginate, potassium chloride, iodine and human food|
|Turbinaria||x||-||x||- Human food and alginate|
|Caulerpa||x||-||xxx||- Human food|
|Chaetomorpha||x||-||xx||- Fish food|
|Cladophora||x||-||xx||- Fish food|
xxx = Extensively utilized; xx = Fairly utilized; x = less utilized.
The author would like to express his gratitude to the following persons who have helped make this possible: Managing Director U Han Tun of the enterprise who allowed the author to attend this workshop; General Manager U Khin Maung Tun whose encouragement was very valuable; Deputy General Manager (Planning and Research) U Hla Myint who, despite his heavy work, read, edited and imputted the manuscript in the computer; Manager (Production Research) U Soe Tun for his advice in the preparation of the paper, and even collecting some of the required data and literature himself; and the staff of the Production Research Section and skilled workers at various experimental sites who provided a lot of valuable data and their findings.
Aung Myint, Min Thein and Kyi Shwe, 1981. Research on Farming method of some Economics Seaweeds. Burma Research Oceanographic Sciences, Nov. 1981. Yangon, Myanmar.
Chen, T. P., 1976. Aquaculture practice in Taiwan.
Chennubhotla, V. S. K., S. Kalimuthu and M. Selvari, 198 . Seaweed culture and its feasibility, Industrial Utilization and Economics. Central Marine Fisheries Research Institute, Cochin 682 018, India.
James, P.S.B.R., V. S. Krishnamurthy Chennubhotla and J. Xavier Rodrigo, 1980. Studies on the fauna associated with the cultured seaweed Gracilaria edulis. Central Marine Fisheries Research Institute, Cochin 682 018, India.
Kyi Shwe, 1972. Culture of seaweed Catenella nipae. M.Sc. Thesis. Department of Marine Biology, Moulmein College.
Kyi Win, 1968. Systematic and economic importance of seaweeds found in Myanmar.
Lay Maung, Saw New Year and Aye Kyaw, 1979. Experimental seaweed culture at Maung Shwe Lay Bay. Research Department, People's Pearl and Fisheries Corporation.
Saw New Year, Aye Kyaw and Nyan Taw, 1988. Pilot scale culture of seaweed Gracilaria edulis and its economics.
Myo Thant Zin and Hla Htay, 1979. Construction of agar production plant. Foodstuff Industries, Ministry of Industry No. 1 (In Myanmar).
Min Thein, 1984. Initial production of nori from Myanmar edible seaweeds. Marine Bio. Department, Moulmein College. (In Myanmar).
Ethel G. Llana
Chief, Seaweeds Section
Fisheries Resources Research Division
Bureau of Fisheries and Aquatic Resources
P.O.Box 623, Manila, Philippines
1. General Information on the Status of Production and Utilization
1.1 General Situation
Official data on seaweed production reveal that the Philippines produced 268,701 metric tons of fresh seaweeds in 1989, valued at over P 604 million or US$ 25.17 million (US$ 1 = P24). Only one percent of the total production was consumed locally as food (usually as fresh salads), while the bulk was absorbed by the local processors and export traders. The quantity of fresh seaweeds used for carrageenan processing was estimated at 249,700 MT (about 93% of the country's seaweed production that year).
Seaweed production data for five years (Table 1) show an upward trend in terms of value and quantity, although there was a drop of 7% from 1985 to 1986. Thenceforth seaweed production grew at the rate of 14% annually. The data apparently represent only the yearly production through culture or farming of Eucheuma, and do not include production from Caulerpa cultivation as well as by gathering of natural stocks of economically important seaweeds such as Gracilaria, Gelidiella, Sargassum, Codium, etc.
Data from the Fisheries Statistics of the Philippines* indicate that the Philippines derives its seaweed production not only from cultivation of certain species. Production, through gathering from natural stocks, ranged from 446 MT to about 3,000 MT from 1983 to 1987 (Table 2). The data are, however, limited to production of seaweed species representing only three genera, namely: Eucheuma, Gracilaria and Caulerpa. Although the figures are insignificant (only from 0.34% to about 2% of the total annual seaweed production) compared to those for the aquaculture sector, nonetheless they point out the fact that the marine fisheries sector also contributes to the country's seaweed production.
* This used to be published annually by the Bureau of Fisheries and Aquatic Resources. The Bureau of Agricultural Statistics has taken over the responsibility of gathering, collating and publishing all agricultural statistics, including that of fisheries. Starting 1988 detailed information such as those in the BFAR Fisheries Statistics, e.g. seaweed production by sector, by region, etc. were no longer available.
|Year||Quantity (mt)||Value ('000 P)|
Source: Bureau of Agricultural Statistics.
|Eucheuma spp.||Gracilaria spp.||Caulerpa spp.|
Source: Bureau of Fisheries and Aquatic Resources.
Official data show that Philippine seaweed exports are in the form of dried, fresh and salted seaweeds as well as kelp meal powder (Table 3). About 31,000 MT of dried seaweeds, valued at more than US$ 37 million, were exported in 1989 mostly to Europe (Denmark, France and the United Kingdom which accounted for about 57% of the total seaweed exports that year) and the U.S.A. (16.4%). About 26% of the total seaweed exports went to the Republic of Korea, Spain, Japan, Australia, Taiwan, West Germany, Hong Kong, Argentina, Ireland, Canada and a few other countries.
Exports of dried seaweeds are not specific to Eucheuma. it is estimated that only 18,386 MT of dried Eucheuma were exported in 1989, comprising 93.5% of the “cottonii” type and 6.5% of the “spinosum” type (Table 4).
Import of dried seaweeds is generally minimal although the quantity has been increasing at an average annual rate of about 74%. From only 0.35 MT in 1985, seaweed import rose to 754 MT in 1989 (Table 5). Imported seaweeds usually come in dried form and of the type that is mainly used in refined carrageenan processing (e.g., Chondrus crispus or “Irish moss”).
|“Cottonii” type||“Spinosum” type|
Source: Seaweed Industry Association of the Philippines.
Source: National Statistics Office.
Philippine seaweed production in 1988 was derived mainly from an estimated total area of 5,700 hectares under cultivation (Table 6). These production areas are concentrated in Western Mindanao and the Central Visayas, which account for 90.5% and 6.5% of the country's total seaweed production (Fig. 1). Potential mariculture areas are estimated at 4,500 ha. This estimate is rather low compared to that of the BFAR's which is approximately 13,000 ha of potential areas available for seaweed farming (Malig, 1990).
A study of the economic and social profile of the seaweed industry in selected areas of the Philippines (Posadas, 1988) revealed that all the farmers interviewed in Tawi-tawi, Zamboanga and Bohol (seaweed-producing areas of the country) employed the monoline method of cultivation.
Figure 1. Location of Eucheuma farms in the Philippines.
|WESTERN MINDANAO - A|
|WESTERN MINDANAO - B|
|Zamboanga del Sur||2,283||70||-|
|Zamboanga del Norte||38,520||660||2,340.9|
|Davao del Norte||26||11||-|
|Davao del Sur||20||7||-|
|Surigao del Sur||239||12||1,107.0|
Source: Bureau of Agricultural Statistics.
The Department of Agriculture, through the Bureau of Fisheries and Aquatic Resources, has drawn up an action plan for seaweed research and development which includes, among others, strategies to increase the area under cultivation and introduce new species for culture. It has also the so-called LEAD (Livelihood Enhancement for Agricultural Development) Program which extends financial assistance for seaweed projects involving production, marketing as well as processing.
1.2 Review of Economic Species
About 350 economically important seaweed species from the Philippines have been listed by Trono and Ganzon-Fortes (1988). More than 150 of these economic species, whose source and level of utilization have been determined, are enumerated in Table 7, including their uses. Majority of the economic species are red algae, comprising more than 60% of the total number of species listed. The brown algae comprise about 25%, while the green algae account for 15%.
Except for the farmed species (Eucheuma denticulatum, E. alvarezii, Caulerpa lentillifera, Enteromorpha clathrata, E. compressa and E. intestinalis), only a few species are extensively utilized. The wild species identified to have high level of utilization include Codium edule, Sargassum (S. cristaefolium, S. granuliferum, S. nigrifolium, S. polycystum and S. siliquosum), Gracilaria “verrucosa” (=G. confervoides) and Gelidiella acerosa. These species are mainly utilized as food or raw material for the manufacture of commercial products. The majority of the species with low level of utilization are sold locally as food.
Among the economic species that are being gathered from natural stocks, a few have potential of being cultured through the application of culture technologies available from other countries (e.g., culture of Gracilaria, Porphyra, etc.).
The Aquaculture Department of the Southeast Asian Fisheries Development Centre in Iloilo is conducting research on Gracilaria biology, culture and processing. The DA-BFAR has a proposed UNDP-assisted project on seaweed production development, particularly on Gracilaria. When approved, this project shall be implemented in Eastern Sorsogon in cooperation with the University of the Philippines (Marine Science Institute), University of Hawaii, and the Bicol University (College of Fisheries).
Research is being done by a private firm (FMC Corporation), through the efforts of Mr. Vicente B. Alvarez (who, together with Dr. Maxwell Doty of the University of Hawaii, pioneered the development of culture technology for Philippine Eucheuma farming), on a few economic species (Eucheuma gelatinae, Halymenia spp. and Grateloupia filicina) for introduction in commercial scale.
2 Information on Production Systems
2.1 Scales of Production
Seaweed farms are classified according to farm size as small (<0.25 ha), medium (0.25–0.50 ha) and large (>0.50 ha). Analysis of monthly production, costs and income data from seaweed farming (Posadas, 1988) showed that, on a per-farm basis, large farms produced about 13,600 kg of seaweeds per farm per month; medium farms, about 8,500 kg; and small farms, about 4,400 kg (Table 8).
In terms of farm stocking density, farms are classified into extensive (<5,000 kg/ha), semi-intensive (5,000–10,000 kg/ha), and intensive (>10,000 kg/ha). The same study showed that the semi-intensive farms gave the highest yield, but are most expensive to maintain. Data obtained in 1988 showed the following average monthly production: 10,295 kg, 13,990 kg and 12,700 kg for extensive, semi-intensive and intensive farms, respectively (Table 9).
|Species||Uses||Level of Utilization||Source|
|Acanthophora spicifera |
= A. orientalis
|Human food; source of carrageenan & agar||2||W|
|A. muscoides||Human food; source of carrageenan; w/ growth regulators (gibberellin and cytokinin)||1||W|
|Agardhiella sp.||Human food|
|Amansia glomerata||Medicine (antibiotic)||1||W|
|Amphiroa zonata||Medicine (antimicrobial)||1||W|
|Asparagopsis taxiformis = A. delilei||Human food; animal feed; source of protein; medicine (antibiotic, antimicrobial)||1||W|
|Bangia fuscopurpurea||Human food||1||W|
|Bostrychia radicaus||Human food||1||W|
|Callophyllis sp.||Human food||2||W|
|Carpopeltis sp.||Human food; material for paste||1||W|
|Catenella impudica||Human food||1||W|
|Ceramium spp.||Source of agar; medicine (antibacterial); material for paste||1||W|
|Chondria spp.||Medicine (vermifuge, antibacterial)||1||W|
|Chondrococcus||Human food; source of|
= Desmia hormemannii
|Corallopsis sp.||Source of agar||1||W|
|Digenea simplex||Source of agar; medicine (vermifuge, laxative); with iodine||1||W|
|Eucheuma arnoldii||Human food; source of carrageenan||2||W|
|E. cottonii||Human food; source of carrageenan||2||W|
|E. isiforme||Human food; source of carrageenan||2||W|
|E. gelatinae||Human food; source of carrageenan||2||W|
= E. muricoatum
= E. spinosum
|Human food; source of carrageenan and agar; controls heavy metal (pb, Cd) pollution||3||C|
|E. alvarezzii(now Kappaphycus alvarezii)||Human food; source of carrageenan and agar; w/minerals; controls heavy metal (pb, Cd) pollution||3||C|
|Galaxaura oblongata||Source of sulfated poly saccharide related to carrageenans||1||W|
|Gelidiella acerosa||Human food; source of|
|Gelidium||Human food; medicine (antifungal, antibacterial, antiviral); source of agar|
|G. pusillum||Human food; source of agar||1||W|
|Gigartina||Human food; source of agar and carrageenan; material for paste||1||W|
|G. gelatinosa||Medicine (antibacterial)||1||W|
|G. tenax||W/ vitamins (folic and folinic acids)||1||W|
|Gracilaria||Human food; source of agar; medicine (laxative); w/Vitamin B; fertilizer||1||W|
|G. arcuata||Human food; animal feed; for wastewater purification & reuse; source of agar (ideal for bacteriological use); w/ growth regulators (auxin, gibberellin & cytokinin)||1||W|
|G. blodgettii||Human food; source of agar||2||W|
|Human food; source of agar||2||W|
|G. coronopifolia||Human food; source of agar; w/ minerals, fats, proteins & Vitamin C||2||W|
|G. debilis||Source of agar||1||W|
|G. edulis||Human food; animal feed; source of agar; for = wastewater purification & reuse||2||W|
|G. eucheumoides||Human food; source of agar (ideal for dessert gel)||2||W|
|G. gigas||W/ Vitamin A||1||W|
|G. laniculata||Source of agar||1||W|
|G. lichenoides||Human food; source of agar; w/ proteins, fats, Vitamin C & iodine; medicine (as alternative; for diarrhea & dysentery; as a pectoral emollient; for pulmonary complaints; for goiter, scrofula, etc.; for poulticing swollen knee joints & unhealthy sores; for leucorrhea & profuse menstrual flow; as a dumulcent for intestinal & bladder difficulties, and jaundice)||2||W|
|Human food; source of agar;food for milkfish; w/proteins & minerals||3||W|
|Grateloupia||Human food; source of agar; material for paste||2||W|
|G. filicina||Human food||2||W|
|Gymnogongrus sp.||Human food; source of carrageenan; material for paste||1||W|
|Hypnea||Human food; source of carrageenan; fertilizer; animal feed; medicine (antitumor); w/protein|
|H. cervicornis||Human food; w/ minerals; source of agar, carrageenan & gelan||1||W|
|H. divaricata||Human food; source of agar||1||W|
|H. musciformis||Human food; source of agar & carrageenan; w/ growth hormone (gibberellin); medicine (vermifuge); w/ fats, proteins & iodine||1||W|
|Human food; source of carrageenan; medicine (antimicrobial); w/ protein||1||W|
|Human food; source of agar; w/ carbohydrates; medicine (antifungal, antibacterial)||1 1||W W|
|L. composita||Human food||1||W|
|Source of agar||1||W|
|L. intermedia||Human food||1||W|
|L. intricata||Human food||1||W|
|L. nipponica||Human food; source of amino acids & chemical product (cyclic ethers)||1||W|
|L. obtusa||Human food; source of amino acids; medicine (antibacterial, antibiotic)||1||W|
|L. okamurai||Human food; w/ vitamins (folic & folinic acids); source of chemical products||1||W|
|L. papillosa||Human food; fish bait; source of agar & carrageenan; medicine (antibacterial)||1||W|
|L. tronoi||W/ growth regulators (auxin, gibberellin & cytokinin); w/ minerals||1||W|
|Liagora farinosa||Human food||1||W|
|Porphyra||Human food; w/ Vitamin B; source of agar; aphrodisiac; medicine (reduces plasma cholesterol level)||2||W|
|P. crispata||Human food||2||W|
|Pterocladia capillacea||Human food; source of agar||1||W|
|Rhodymenia||Human food; animal feed; w/ Vitamin B||1||W|
|Scinaia hormoides||Human food||2||W|
|Wrangelia argus||Medicine (antibiotic, antifungal)||1||W|
|Chnoospora implexa||Source of food||1||W|
|C. minima||Source of food||1||W|
|Colpomenia sinuosa||Human food; source of phenols & algin; w/ vitamins (folic & folinic acids)||1||W|
|Cystoseira sp.||Medicine (antibacterial, antifungal); source of alginates, tannins & phenols||1||W|
|Dictyota||Medicine (antibacterial); source of algin; w/ proteins & minerals|
|D. dichotoma||Human food; source of phenols; w. vitamins (folic & folinic acids)||1||W|
|D. linearis||Source of algin||1||W|
|Hormophysa triquetra||Human food; source of algin; fertilizer||2||W|
= H. cancellatus
|Human food; source of algin; animal feed||2||W|
|H. tenuis||Human food||1||W|
|Padina||Source of algin; fertilizer||1||W|
|P. australis||Human food; source of alginic acid||1||W|
|P. commersonii||Human food||1||W|
|P. japonica||Source of algin||1||W|
|P. tetrastromatica||Human food||1||W|
|Sargassum spp.||Human food; animal feed; fertilizer; w/ iodine, Vitamin C, protein & minerals; medicine (for goiter & other glandular troubles, antibacterial, antitumor); source of algin, tannins & phenols||3||W|
|Human food; source of algin; W/ growth regulators (auxin, gibberellin & cytokinin) & protein||3||W|
|S. granuliferum||Human food; W/ protein||3||W|
|S. nigrifolium||Human food; W/ vitamins (folic & folinic acids)||3||W|
|S. polycystum||Human food; source of algin; W/ auxinlike substance; controls heavy metal (Pb, Cd) pollution||3||W|
|S. serratifolium||Human food; W/ protein||3||W|
|S. siliquosum||Human food; W/ protein||3||W|
|Turbinaria||Human food; fertilizer; source of algin, tannins & phenols; insect repellant||1||W|
|T.conoides||Human food; source of algin; W/ minerals||1||W|
|T. ornata||Human food; source of algin||1||W|
|Acetabularia major||Medicine (for renal troubles)||1||W|
|Caulerpa||Human food; medicine (loers blood pressure, antifungal)||1||W|
|C. clavifera||Human food||1||W|
|C. laetivirens||Human food||1||W|
|C. lentillifera||Human food||3||W|
|C. macrodisca||Human food||1||W|
|C. microphysa||Human food||1||W|
|C. peltata||Human food||1||W|
|C. racemosa||Human food||1||W|
|C. serrulata||Human food||1||W|
|C. sertularioides||Human food||1||W|
|C. taxifolia||Human food||1||W|
|Chaetomorpha aerea||Food for milkfish||1||W/C|
|C. antennina||Human food||1||W|
|C. brachygona||Human food||1||W|
|C. crassa||Human food||1||W|
|C. linum||Human food||1||W|
|Cladophora spp.||Animal feed; medicine (antibacterial, antiviral); source of protein||1||W|
|Codium||Human food; medicine (antibacterial & antitumor)|
|C. bartlettii||Human food||1||W|
|C. edule||Human food||3||W|
|C. geppii||Human food||1||W|
|C. intricatum||Human food||1||W|
|C. muelleri||Human food||1||W|
|C. papillatum||Human food||1||W|
|C. tenue||Human food||1||W|
|C. tomentosum||Human food||1||W|
|Dictyosphaeria cavernosa||Medicine (antimicrobial)||1||W|
|Enteromorpha||Human food; animal feed fertilizer; medicine (antibacterial); w/ Vitamin A|
|E. clathrata||Human food||3||W/C|
|E. compressa||Human food; medicine (reduces plasma cholesterol level)||3||W/C|
|E. intestinalis||Human food; food for milkfish; w/ Vitamin E & protein; animal feed; source of tocopherols||3||W/C|
|H. macroloba||W/ growth regulators (auxin, gibberellin & cytokinin)||1||W|
|H. tuna||Animal feed||1||W|
|Monostroma||Human food; medicine (antibacterial)||2||W|
|M. nitidum||Human food; medicine (reduces plasma cholesterol level)||2||W|
|Ulva||Human food; animal feed; fertilizer; medicine (antibacterial)|
|U. fasciata||Human food||2||W|
|U. lactuca||Human food; medicine (vermifuge); w/ minerals, tocopherols, Vitamin C & proteins||2||W|
|U. pertusa||Human food; medicine (reduces plasma cholesterol level, antibiotic); w/ vitamins (folic & folinic acids)||1||W|
|U. reticulata||Human food||1||W|
|Valonia aegagropila||Human food||1||W|
* Adapted from Table 1 in Trono and Ganzon-Fortes (1988); species list includes onlythose level of utilization and source have been determined.
2.2 Methods of Production
Seaweed production in the Philippines comes from two sources, namely: through mariculture or farming (in open waters), or pond culture; and through gathering of natural stocks. Around 90% of the total national production is derived from farming of Eucheuma alvarezii, E. denticulatum and Caulerpa lentillifera. The rest comes from the gathering of natural stocks of edible seaweeds, with the exception of Sargassum which is collected in commercial quantities for processing into seaweed meal, and Gracilaria spp. and Gelidiella acerosa for agar processing (Trono and Ganzon-Fortes, 1988).
|Seaweed production (kg)|
|Per farm/mo ++||4,394||8,470||13,626||11,706|
|Per ha/mo ++||33,804||19,022||13,517||15,697|
|Per farm ++||1,268||994||1,839||1,536|
|Per ha ++||9,756||2,466||1,794||2,128|
|Per farm ++||660||6,190||12,395||10,076|
|Per farm ++||1,928||7,204||14,249||11,630|
|Per farm ++||3,758||8,264||15,336||12,716|
|Per farm ++||3,099||2,054||2,925||2,622|
++ Significantly different at 1%.;
+ Significantly different at 5%.
Entries in per kilogram were not subjected to one-way ANDVA.
Source: Posadas (1988).
|Seaweed production (kg)|
|Per ha/mo +||13,287||18,756||20,519||15,697|
|Per ha +||2,533||1,547||1,574||2,128|
|Per farm ++||7,179||16,967||15,930||10,076|
|Per ha ++||9,543||16,886||17,223||12,601|
|Per farm ++||8,702||18,624||17,320||11,630|
|Per ha ++||12,095||18,474||18,838||14,758|
|Per farm ++||11,368||21,242||19,155||14,252|
|Per farm ++||9,867||19,592||17,766||12,716|
|Per ha +||13,689||19,778||20,881||16,297|
|Per farm ++||2,666||2,618||1,835||2,622|
|Per ha +||4,127||2,851||3,617||3,667|
++ Significantly different at 1%.;
+ Significantly different at 5%.
Entries in per kilogram were not subjected to one-way ANDVA.
Source: Posadas (1988).
Mariculture of Eucheuma
The vegetative method of culture, through regeneration of fragmented thalli, has been successfully applied to some Philippine species. Kappaphycus alvarezii (=E. alvarezii) and E. denticulatum are the two species presently cultured in the Philippines in open waters. Both species are cultivated using the same method, the monoline method, so called because it makes use of monofilament lines onto which Eucheuma cuttings are tied by means of soft plastic material.
This method is used by small family farms and large company farms. It has replaced the culture methods earlier practiced by Eucheuma farmers, namely: the simple bottom culture, and other methods which utilize some form of a support system such as the raft method, net method and fixed off-bottom culture.
Monolines are constructed by means of wooden stakes, driven deep into the substrate 10 m apart and 1 m between rows, in such a fashion that they form plots (Fig. 2a). The monolines are attached to these stakes, about 0.3–0.5 m from the bottom (depending on the water depth at low tide). Eucheuma cuttings, weighing 100–150 g, are tied (at 25–30 cm interval) using soft plastic straw.
Monolines are positioned parallel to or against the direction of the current, depending on the current velocity. In areas with relatively strong current, the monolines are arranged parallel to the current and an extra stake is placed midway between the original rows of stakes for extra support. Occasionally, an adaptation of the raft method is used in the monoline system, in which the monolines are suspended horizontally from a rectangular bamboo raft (Fig. 2b).
The plants are allowed to grow to one kilogram or more before they are harvested, usually after 2–4 months depending on the growth rates. The fast growing K. alvarezii, however, is usually harvested in 45 to 60 days from planting. Harvesting is done by removing the entire monoline and replacing the whole plants with new cuttings.
Pond culture of Caulerpa
In Caulerpa cultivation, the old practice of broadcasting cuttings into the ponds has been replaced by the more efficient method of sticking into the mud one end of a handful of Caulerpa cuttings at about 50-cm interval. This method makes use of guides or marks in planting to ensure a uniform distribution of seeds on the pond bottom.
To facilitate planting, Caulerpa ponds are first drained to a depth of 0.3 m. After planting, the ponds are flooded (slowly so as not to uproot the newly planted cuttings) to a depth of 0.5–0.8 m. Caulerpa ponds are divided into compartments of 0.10-0.25 ha; each compartment is provided with intake and outflow gates to facilitate drainage and flooding.
The first harvest may be made 1-2 months after planting, depending on the growth rates but usually when the pond bottom is uniformly covered with growth.
Figure 2. (A) Bottom monoline method and (B) floating monoline-bamboo method of farming Eucheuma. (Source: Veloso, 1990).
Gracilaria and Porphyra culture
Although the culture technology for Gracilaria is available, it has not been adopted in the Philippines for the commercial production of this agarophyte. Similarly, the technology for Porphyra culture, which is well known in Japan, Korea and China, has not also been adopted in the country for the commercial production of this seaweed in Northern Philippines where local stock is present.
Production of Gracilaria and Porphyra in the Philippines is therefore still dependent on the availability of natural stocks. Experimental works, however, have been initiated on pond and field culture of G. “verrucosa” (= G. confervoides) as well as on Porphyra culture.
Initial studies on the field culture of G. “verrucosa” utilizing natural spore recruitment and through the improvement of substrate using adobe and hollow cement blocks arranged into plots have been done by the Bureau of Fisheries and Aquatic Resources. Production results showed that the amount produced in the control (sandy-muddy) or natural substrate (Trono and Ganzon-Fortes, 1988).
An unpublished article on the successful isolation of Porphyra spores by Arcangel Balicanta reveals that research work on Porphyra culture, utilizing oyster shells as substrate, was done in 1975 at the BFAR Station in Bobon, Burgos, Ilocos Norte. Attempts to improve Porphyra production through natural spore recruitment process are being done using bamboo branches as substrate.
Species gathered from natural stocks
About 150 species of economically important seaweeds are being gathered from natural stocks (Table 7). The species that are most commonly gathered are Gelidiella acerosa, Gracilaria “verrucosa”, Sargassum spp. and Codium edule, including Enteromorpha spp.
Methods of harvesting vary depending on the species, size, abundance and habitat where these seaweeds are found. In reef areas where harvestable crops are closely associated with other species, selective harvesting, through hand picking and/or pruning, is the most common method of cropping. In shallow bays, the gathering of Gracilaria is done by hand, or with the use of rakes. In some instances, semi-mechanized method is employed using trawl-like equipment attached to a slow-moving motorized small boat (banca). In deeper areas, diving and hand picking, or the use of pruning tools, are employed. In wave-exposed areas where hand picking is hazardous, the gathering of seaweed crops is mostly dependent on drift materials which accumulate on the shore especially after some heavy surfs (Trono, 1988a).
3 Economics of Production
Comparative data on costs and returns of various scales of production, that is, by farm size (i.e., small-, medium-, and large-scale) and by seeding rate (i.e., extensive, semi-intensive, and intensive) are shown in Tables 8 and 9, respectively.
Large farms obviously produce more than the medium and small farms, but small farms incur lesser total costs than the medium and large farms. Hence, small farms obtain higher net profit than the large and medium farms. In terms of seeding rate or stocking density, semi- intensive farms produce the highest yield but are most expensive to maintain. The intensive mehtod is effective but this advantage is offset by the high cost of production involved; the extensive farms derive higher farm net profits than the semi-intensive and intensive farms.
The relative efficiency of seaweed farms, viewed from the cost and profitability indicators, measured per kilogram of wet seaweeds produced, showed that small farms are less expensive to operate and provide higher level of profits (Posadas, 1988).
A study by Smith and Pestano-Smith (1980) on the economics of seaweed farming revealed the following findings:
Initial capital outlay for most families was approximately $ 800 to cover monoline, stakes, hand tools, baskets, lease, seed plants and tying materials. All labour was family supplied at this early stage. The first harvest came 75–90 d later, and then averaged 650–700 kg/mo thereafter. Prices received were as high as $ 0.58/kg, so that the initial capital outlay was repaid within 6 months. An extensively operated farm producing 8 t/yr of dried E. spinosum, would return a total annual revenue of $ 4,640 or $ 1,100 over annual production costs including depreciation and family labour valued at its opportunity cost of $ 2.70/d. An intensively operated farm was even more profitable, giving a total annual revenue of $ 11,600 or $ 4,400 over annual production cost. The breakeven price was $ 0.44/kg and $ 0.36/kg for the extensive and intensive operations, respectively.
4. Processing and Utilization
4.1. Status of Processing
More than 50% of Philippine Eucheuma harvests are utilized by local processors in the manufacture of carrageenan products, which generated about 62% of the foreign exchange earnings in 1987 (Ricohermoso, 1988).
Philippine Eucheuma processed products are either kappa- or iota- carrageenan blended materials ready for use in their respective applications. These are manufactured either by non-extractive or extractive method.
The non-extractive method, apparently that used for semi-refined carrageenan (SRC) processing, was introduced in the country by Japanese chemists in 1978 through a joint venture with Marcel Trading Corporation. This method involves cooking of the dried seaweed material in alkali solution to a desired modification level, washing, drying (either solar or mechanical), grinding and blending to customer's specifications. Rigid quality control is observed in the process.
In SRC processing, most of the non-carrageenan matter in the seaweed is dissolved and removed, leaving a solid residue of carrageenan which is dried and milled. The process is faster and cheaper but the product contains some cellulose and does not form clear gel (Trono and Ganzon- Fortes, 1988).
The extractive method, used in refined carrageenan processing, involves alkaline cooking of the dried seaweed material, and more highly sophisticated and technically advanced potassium chloride or alcohol extraction system.
Six companies based in Cebu are involved in SRC processing. One of these companies, the Shemberg Marketing Corporation, is at present manufacturing refined carrageenan and plans to expand its production capacity to 1,200 MT (Table 10). As of 1989, the annual rated capacity of these local carrageenan processors was 9,840 MT, reflecting an increase of 28% from the 1987 capacity of 7,700 MT.
Agar processing is an established technology in the country as evidenced by the existence of agar manufacturing plants. The method simply involves pasting the raw materials, washing and drying (either solar or mechanical). Agar products usually come in the form of bars or strips.
Sargassum processing involves sorting, cleaning, drying and grinding. Sargassum materials are delivered by fishermen/seaweed gatherers at 30–40% moisture content. The local processor-exporter redries the materials at 14–18%; these are milled to about 10 mesh (Ricohermoso, 1988).
|Marcel Trading Corporation||1,800||-||500|
|Asia Pacific Colloids - FMC||2,340||-||-|
|Shemberg Marketing Corporation||2,000||800||1,200|
|Philippine Bio-Industries, Inc.||-||-||400|
Source: Foundation for Educational Evolution and Development, Inc., 1990.
4.2 Status of Utilization
Seaweeds produced in the country are marketed by fishermen/farmers in fresh or dried form. Fresh seaweeds are sold in markets, either as fresh or dried vegetables, or in thin sheets (for Porphyra and Ulva), for local consumption. Dried seaweeds are generally used as raw material for the production of seaweed gums. Only one percent of the country's seaweed production is consumed locally as food; the rest are marketed in dried form for the production of various seaweed products or for export.
Eucheuma seaweeds are processed and marketed in the following forms: dried, alkali-treated chips, semi-refined carrageenan, refined carrageenan, and ready-to eat jelly. The domestic market absorbs only a small fraction of locally processed seaweeds.
The bulk of Philippine seaweed exports comprises raw materials of Eucheuma “cottonii” type, ranging annually from 66% to about 75% of the total exports during the same period. Europe (England, Denmark, France) absorbs most of the Philippine Eucheuma processed products. Local applications of SRC are limited to beer clarification.
The local consumption pattern for refined carrageenan is as follows: ice cream product, 42%; toothpaste, 41%; and desserts/sweets, 17% (FEED, 1990, citing UNIDO report of October 1988). Exports of carrageenan grew at a compounded annual rate of almost 12% from 3,200 MT in 1982 to almost 7,000 MT in 1989. Refined carrageenan exports tripled from about 260 MT in 1987 to almost 900 MT in 1989.
4.3 Quality Standards
In general, the quality requirements for seaweeds used for commercial extraction purposes are more stringent than those which are directly sold in markets as fresh or dried vegetables. The quality requirements of commercial-scale buyers are low moisture content and purity of dried seaweeds. Moisture content of the produce must not exceed 25–30% and these must be free of foreign matter, e.g., other weeds, sand, pieces of shell, coral and other extraneous materials. Farm-produced weeds are generally of higher quality than those gathered from natural stocks (Trono and Ganzon-Fortes, 1988).
5 Marketing of Seaweeds and Seaweed Products
The common system of marketing is generally simple. Small-scale gatherers (fishermen/farmers) may sell their produce directly in the local markets. Large-scale gatherers bring their produce at landing areas to distributors and/or vendors who buy these in bulk. Others, however, dry the seaweeds and sell primarily to buying agents or collectors.
There are two types of buying agents: the independent agent who receives commissions, and the salaried agent of local subsidiaries. The collectors sell to viajeros, who then sell to the traders/processors. The seaweeds are thereafter exported dried or further processed into carrageenan which is also exported (Fig. 3 and 11).
The process, however, becomes complicated by the relationships and contractual arrangements. For instance, a transaction scheme may enable the viajeros to avail of commissions for the use of capital extended by processors/traders. The amount of commission depends on the relationship between the viajeros and the processors/traders. Likewise, the buying agents' relationship with the processors/traders may be financial in nature wherein the former are given cash advances by the latter. This marketing scheme often extends to the farmer level, with the farmers often getting cash advances from buyers who thereby practically acquire buying rights over the farmer's produce.
In Tawi-tawi, the distribution flow differs slightly in that most seaweed farmers sell their dried seaweeds to traders located in the provincial capital. These traders redry the seaweeds and sell these on a commission basis to processors in Zamboanga or Cebu. Traders advance the money for the purchase of production inputs and deduct these amounts from the payments due the farmers for the dried seaweeds (FEED, 1990).
Pricing is determined by several factors, e.g., distance of the gathering area from the market outlets, the amount of supply and the number of people through whom the product is channeled in the retail market, and moisture content and quality of the raw material, etc. Usually, however, processors and exporters determine the local price of seaweeds.
In Tawi-Tawi, the price of dried seaweeds is affected mainly by the moisture content and quality of the material. Before the price is applied, the traders generally adjust the weight of the dried seaweeds based on preset standards on moisture and foreign matter content. Amounts advanced by the traders to the farmers are likewise deducted from the payments due the farmers. However, farmers claim that the traders often take advantage of them in terms of pricing, especially when cash or inputs have been advanced to them by the traders. The traders allegedly deduct a bigger percentage from the seaweed weight than what should normally be deducted based on moisture and foreign matter content. (FEED, 1990)
Prices of dried Eucheuma have generally been on the uptrend since 1984, ranging from P 2.98/kg to P 9.50/kg (farmgate price) and P 6.02/kg to P 11.00/kg (wholesale price). At present, the price of dried Eucheuma ranges from around 11–12 pesos/kg (FEED, 1990).
6 Problems and Needs
The Philippine seaweed industry has thrived for more than two decades now. It has established its identity in the international trade, ranking fourth among the world's producers of red seaweeds. The country is now the leading producer of raw (dried) Eucheuma and semi- refined carrageenan (SRC), contributing about 70% of the world supply. Seaweed and seaweed products rank third among the Philippine export commodities, surpassed only by shrimps and tuna.
Figure 3. Distribution channels of local seaweeds. (Source: FEED, 1990).
|BUYERS||CGN||RAW COTT||EUCHEUMA SPIN||CGN||RAW COTT||EUCHEUMA SPIN||CGN||REF||RAW COTT||EUCHEUMA SPIN||CGN||REF||RAW COTT||EUCHEUMA SPIN||CGN||REF||RAW COTT||EUCHEUMA SPIN|
Source: Ricohermoso, 1990.
Despite these strengths, the local seaweed industry has also experienced problems which, if not given prompt and proper concern, may lead to the loss of the advantages that it has built up.
The problems involve those in the aspects of production, post- production, processing, marketing and utilization of seaweeds and seaweed products.
Production problems include low output due to typhoons, “ice-ice” syndrome, lack of seedlings, or planting material, highly fluid pricing, etc., which result in the cyclic fluctuations in production. There is an urgent need to stabilize production in relation to the demand in the international market. There is also a need to diversify the resource base of the industry to include development of other seaweed species as well as potential production areas; and to increase raw material quality through strain selection studies.
Poor quality produce brought about by poor post-harvest handling practices is another problem. There is a need to improve drying techniques and post-production facilities that would result in the produce conforming to the strict quality requirements of processors in order to further strengthen the Philippines' position in the world market.
In the processing aspect, the 2% AIM (acid insoluble matter) limit on SRC or Philippine Natural Grade (PNG) carrageenan to make it generally acceptable in the U.S.A. and Europe as food additive, has been a controversial issue. Although the ban has been lifted by the U.S. Food and Drugs Administration only recently, there is still a need to conduct toxicological studies to comply with the requirement of the FAO/WHO/JECFA (Joint Experts Committee on Food Additives).
Weak and inefficient marketing/pricing system is another problem that needs immediate concern. The industry has always been subjected to the unstable buying/pricing policy of traders which is dictated by the demand in the international market. This results in erratic production (since seaweed farmers, whose resources are usually tied up with their produce, are generally affected) which, in turn, may create a negative effect on the buyers in the world market who demand high quality produce and dependable supply. This problem, if not remedied, may force foreign buyers/processors to look for other sources in other countries; hence, the Philippines may stand to lose a significant part of its share in the world market. There is therefore a need to stabilize the marketing and pricing system for a more equitable distribution of industry benefits especially to the farmers.
There is a need to diversify or expand utilization of seaweeds and seaweed products. At present, commercial utilization of seaweeds is limited to a few local applications (i.e., beer clarification; ice cream, toothpaste and dessert products).
8 Research and Development Activities and Capability
Research and technological development activities, involving resources and stock assessment, biology and ecology, culture and management techniques, etc., are being undertaken by different agencies, institutions as well as the private sector.
The University of the Philippines Marine Science Institute (UPMSI) has been undertaking major research activities such as genetic studies leading to the establishment of a Eucheuma seedling bank in the Central Visayas; culture and management studies on Gelidiella acerosa, and other commercially important seaweed species in Pangasinan Province; biology and ecology of Sargassum in Bolinao, Pangasinan.
The Aquaculture Department of the Southeast Asian Fisheries Development Centre in Iloilo has been conducting studies on stock assessment, culture and processing of Gracilaria. The Bureau of Fisheries and Aquatic Resources (BFAR) has an on-going research project on the assessment of the seaweed resources and associated invertebrates in Eastern Sorsogon. Other institutions that have some related research are the University of San Carlos in Cebu, Silliman University in Dumaguete City, and the regional fisheries institutions.
Development efforts to attain and sustain a higher level of production through improved culture techniques are a major priority of the private sector. Shemberg Marketing Corporation, FMC Corporation, MCPI Corporation and other big seaweed companies are conducting their own research. Among the agencies involved in the technological development are selected regional stations of the Department of Agriculture (DA), and the Southern Philippines Development Authority.
Studies on post-harvest technology and seaweeds processing and utilization are a continuing activity of agencies and institutions like the BFAR, UPMSI, University of the Philippines in the Visayas College of Fisheries, Bicol University College of Fisheries, and private firms. Industrial research along this line is the responsibility of the Department of Science and Technology.
Training and information development and exchange among these establishments have been going on. The UPMSI has put up a Seaweed Information Centre (SICEN) with IDRC assistance.
The government is exerting efforts to develop further the local seaweed industry. Priority areas for research and development include expansion of production areas; improvement in the productivity of farmed Eucheuma strains; inventory, assessment and management of natural stocks of economically important seaweed species; and chemistry of natural products from seaweeds (Trono, 1990).
The Department of Agriculture (DA), through the BFAR, has prepared an action programme on seaweed research and development which involves, among others, specific activities to increase production and quality of raw material, improve post-harvest facilities, formulate export regulations, improve transport and marketing facilities, etc. DA's LEAD Programme and the Quedan Guaranty Fund Board are extending financial assistance to seaweed projects particularly by small farmers. The Department of Trade and Industry is helping the industry in the marketing and promotion aspects.
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Food and Agriculture Organization. 1986. Seaweed culture in the Asia-Pacific Region. RAPA Publication 1987/8. Bangkok: Reg'l. Office for Asia and the Pacific (RAPA). 41p.
Foundation for Educational Evolution and Development, Inc. 1990. Bohol seaweed production and marketing project - feasibility study. Department of Agriculture, Philippines. 88p. + annexes.
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Malig, J.B. 1990. Identified new possible seaweed farming areas and their viability. Paper presented at the 5th Seaweed Industry Conference, 30 31 March 1990, Cebu Plaza Hotel, Cebu City.
Posadas, B.C. 1988. An economic and social analysis of the seaweeds industry in selected areas in the Philippines. Asian Fisheries Social Science Research Network Research Report. University of the Philippines in the Visayas, Iloilo City. 64p.
Ricohermoso, M.A. 1988. Seaweed industry in the Philippines. In: Report on the Training Course on Seaweed Farming. ASEAN/SF/88/GEN/6, pp. 71 – 75.
Shemberg Marketing Corporation. 1990. Handbook guide to seaweeds (Eucheuma) farming (a business or a livelihood). Technology and Livelihood Resource Centre, Metro Manila. 12p.
Smith, I.R. and R. Pestano-Smith. 1980. A fishing community's response to seaweed farming. ICLARM Newsl. 3(3): 6 – 8.
Trono, G.Jr.C. 1988a. Production of economically important seaweeds through culture and harvesting of natural stocks. In: Report on the Training Course on Seaweed Farming. ASEAN/SF/88/GEN/6, pp. 59–70.
Trono, G.Jr.C. 1988b. Progress and problems in seaweed culture. Ibid., pp. 76-80.
Trono, G.Jr.C. 1990. Priority areas in seaweed resources research and development in the Philippines. Paper delivered at the Dr. Gregorio T. Velasquez Lecture Series on Current Phycological Research, 23 February, U.P. Los Banos. 10p.
Trono, G.Jr.C. and E.T. Ganzon-Fortes. 1988. Philippine Seaweeds. Metro Manila: National Book Store, Inc. 330p.
Veloso, A.R.V. 1990. Eucheuma farming in the Philippines. Dating-bayan Agro-Industrial Corp., Cebu City. 12p.