SEAWEED

S 27

DAUGHERTY, B.K. and K.T. BIRD
Salinity and temperature effects on agar production from Gracilaria verrucosa strain G-16.
1988   9 pp
Aquaculture, 75, 105–113

The effects of 33, 25 and 17% salinity on the productivity and agar production of Gracilaria verrucosa Strain G-16 were compared during three distinct temperature periods in greenhouse cultivation trials. Salinities of 17‰ consistently resulted in low productivity and low agar gel strengths. The experimental periods which encompassed environmental extremes in seasonal temperature changes also showed significant differences in productivity, agar yields, and agar gel strength. Best gel strength resulted during the experimental period with minimal temperature fluctuations in a physiologically favorable range, and at 25 and 33‰. Algal productivity demonstrated acclimation responses to variable temperatures. Agar gel strength tended to respond to extremes in temperature, rather than median temperatures. The results suggest that while numerous sites may provide high biomass yields, temperature and salinity extremes may adversely affect agar product quality.

S 28

GELLENBECK, K.W., KRAEMER, G.P., MCMURTRY, L.A and D.J. CHAPMAN
An experimental culture system for macroalgae and other aquatic life.
1988   7 pp
Aquaculture, 74, 385–391

A small-scale culture system originally designed for seaweed culture (Sargassum muticum and Egregia menziesii) is described. The versatility, low cost, and reliability of the tank make the design applicable to experimentation with a wide variety of aquatic organisms. Sectioned polyvinyl chloride (PVC) irrigation pipe is divided with plexiglas partitions to form a wide variety of tank volumes. Seawater flow and nutrient additions are controlled so that nutrient uptake can be measured and regulated. Protection systems are included allow the system to operate without frequent monitoring adjustment.

S 24/1

COASSINI and L.LOKAR
Culture and exploitation of algae in brackish waters.
1980   10 pp
Nova Thalassia, no. suppl. 4, 163–182

The necessity of mass culture of Rhodophyceae of industrial interest is shown. The investigation is limited to Gracilaria sp., of which G. verrucosa (Huds.) Papenfuss, is a spontaneous and abundant species in Adriatic Sea. After describing the species and indicating the optimal growth and development parameters in nature, the chemical composition of the seaweed and of the agar which it produces were reported and also the methods and extraction and the principal uses of it. After examining the most recent cultivation methods of seaweed, both in natural and artificial environment, it was concluded that the most productive methods seem the multi-species aquaculture systems, which give good results either in nature or in basins. They may be linked to oyster cultures utilizing their waste-waters for the growth of the seaweed which is acting as a biological filter, in order of reducing the excess of nutrients from water.

S 24/2

TRONO, G.C. Jr and E. GANZON-FORTES (Eds)
Field culture of gracilaria and other species.
1981   5 pp
Rep. Train. Course on Gracilaria, FAO/UNDP Project
RAS/79/041 implemented through RAS/74/013, Philippines, 1–30 April, 51–551981

The field culture of Gracilaria and Eucheuma in the Philippines is discussed. Production data for Gracilaria in the farm and outside the farm are also presented.

S 24/3

TRONO, G.C. Jr. and E. GANZON-FORTES (Eds)
Pond culture of seaweed.
1981   4 pp
Rep. Train, Course on Gracilaria, FAO/UNDP Project
RAS/70/041 implemented through RAS/74/013, Philippines, 1–30 April, 47–50

Pond culture of seaweeds appears to be a good alternative in many areas where the culture of fish and shrimps have become very unproductive. The culture of Gracilaria and Caulerpa are described in detail.

S 24/4

TRONO, G.C. Jr. and E. GANZON-FORTES (Eds)
The ‘ice-ice’ problem in seaweed farming.
1981   7 pp
Rep. Train. Course on Gracilaria, FAO/UNDP Project
RAS/79/041 implemented through RAS/74/013, Philippines, 1–30 April, 69–75

A study was carried out to determine which factor(s) causes the ‘ice-ice’ problem in Eucheuma. The isolation, identification and cultivation of microorganisms from Eucheuma samples obtained from the field were undertaken. Field studies were also carried out in seaweed habitats to look at the abiotic and biotic factors and correlate them with the incidence of ‘ice-ice’. No specific bacteria was found associated with the incidence of the disease, but possible correlation was found between phosphate concentration in the seaweed habitat and the incidence of ‘ice-ice’.

S 24/5

MASUO, M.
Recent aquaculture in Japan.
1982   64 pp
Rep. Train. Course on Seabass spawning and larval rearing, Songkhla, Thailand, 1–20 June, 1982, 64 p

Aquaculture in Japan consists mainly of the following species: yellowfish (Seriola quinqueradiata), red seabream (Chrysophrys major) oyster (Crassostrea gigas), scallop (Patinopecten yessoensis) and seaweeds (Porphyra, Undaria). Mass culture of seed for fish farming is discussed together with the Marine Ranching Programme, which combines the maintenance of seed animals, management of production and control of the enviornment.

S 24/6

CHRISTIAEN, D.
Biochemical study of Gracilaria verrucosa. Agar: biological and physiochemical factors influencing its quality and its industrial production.
1981   103 pp
Univ. Sci. Tech. de Lilli, Lilli (France), 1981, 103 p

The agar molecule is still not well known and its industrial production is irregular. The study of Gracilaria verrucosa shows that agar production is better in the cold season; this is due to 3, 6 anhydrogalactose. The agar production is lower in the summer due to higher nitrogen levels in the sea water and due to algal growth. A relation has been observed between the protein composition and the polysaccharidic composition, which brought the following question: must agar be considered as a glycoprotein? The relation of dry weight-agar production can help detect the best agar-producing algae.

S 24/7

LIU, S.J. and S.F. ZENG
Rate of photosynthesis and growth of Gracilaria verrucosa in different layers of seawater.
1982   6 pp
J. Fish. China, vol. 6. no. 1, 59–64

Rate of photosynthesis and growth of Gracilaria verrucosa in different layers of seawater in Shanwei Wan was observed. When the algae were reared near the surface layer of seawater, the rate of photosynthesis and growth was was fast. However if reared in the lower layer of seawater, their rate of photosynthesis and growth was slow. There is a compensation layer of the depth of transparency in the sea waters. At this layer the amount of oxygen produced in the photosynthesis is almost equal to that consumed in the respiratory process of the algae. Below this depth of transparency in seawater, the growth of the algae nearly stopped. In order to get a good harvest in the artificial raft cultivation, Gracilaria should be floated near the surface of seawater. If the transparency of seawater is high, the algae should be cultivated on the ropes hanging from the raft to proper depth, the length of the ropes should not exceed 1.5 meter.

S 24/8

GIACCONE, G., PRINCI, M., FEOLI, E., LONGO, L. and V. TORTUL
Evaluation of the lagunar vegetation resources of the Tyrrhenian Sea & experiments on the controlled cultivation of the red alga Gracilaria verrucosa & of other agarophytes.Sicily
1979   3 pp
Proc. Nat. Sci. Meeting, Rome 5–6–7 March, 1979, Vol. 1, 423–435

Two aims are proposed for red algae agarophyte Gracilaria verrucosa cultivation experiments: (1) pilot plant performance to increase biological resources in coastal biotopes and (2) recycling fertilizers from municipal wastewater disposals by aquaculture seaweed farms. The results from cultivation experiments have been successful and their utilization to a large industrial extent is advisable. Fertilizer utilization by heteretophic and autetrophic algal metabolism suggests the planting of a Gracilaria antidistrophic barrier downhill from municipal wastewater disposals.

S 24/9

FAO
People's Republic of China. The alginate industry in China.
1981   29 pp
FAO, Rome (Italy), 1981, 29 p

Kelp (Laminaria japonica) has been widely raised in China for more than 20 years, however, its quality is poor and multipurpose utilization has been limited. Kelp cultivation and algin production are discussed and the problems concerning cost and quality of algin outlined. The production of by-products such as mannitol and iodine is also considered. The major findings are summarized as follows: 1) the processes used for alginate extraction in China need improvement to reduce the cost of production which is too high; 2) some of the equipment currently used is inefficient and should be replaced with more mode efficient equipment to improve the quality of alginate produced; and 3) senior level engineers and chemists should undertake a study tour to visit modern equipment manufactured and alginate uses outside China.

S 24/10

PCARR
The culture of seaweed.
1981   20 pp
Technology, Los Banos, PCARR, Los Banos (Philippines), 1981, 20 p

A brief review of the technical and economic feasibility of Eucheuma farming the Philippines is presented.

S 24/11

CHENNUBHOTLA, V.S.K., KALIAPERUMAL, N. and S. KALIMUTHU
Culture of Gracilaria edulis in the inshore waters of Gulf of Mannar (Mandapan).
1978   2 pp
Indian J. Fish., vol. 25, nos. 1–2, 228–229

The possibilities and advantages submerged floating culture of G. edulis in the inshore water of the Gulf of Mannar are discussed. Observations suggest that pure strain of the alga could be harvested without contamination and much sedimentation.

S 24/12

GLUBE, J.B.
The potential for seafarming in the Riau Archipelago, district of Indonesia.
1982   33 pp
FAO/UNDP, Manila (Philippines), 1982, 33 p

A survey of the potential for seafarming in the Riau Archipelago District was conducted during July 1981. Potential for farming oysters, (Crassostrea) groupers, (Plectropomus, Epinephelus), rabbitfishes, (Siganus), seaweeds (Eucheuma spinosum), and green mussels (Perna viridis) was identified in the Riau Islands. Farming of groupers and oysters is recommended for the Anambas Islands. Aquaculture trials proposed to be completed under project GCP/INS/056/CAN are described. Several recommendations for government actions to expand seafarming are included.

S 24/13

KANG, J.W.
Some seaweed diseases occurred at seaweed farms along the south-eastern coast of Korea.
1982   6 pp
Bull. Korean Fish. Soc., vol. 14, no. 3, 165–170

An unknown microbial disease and some parasitic crustaceans currently prevailing in the seaweed farms of Undaria pinnatifida along the south-eastern coast of Korea are described. 1) Green spot probably caused by the microbial pathogens were found on the fronds of U. pinnatifida. Examination reveled that the diseased fronds bore a number of viable bacteria, 6.8×10 super (5) to 1.2×10 super (6) per gram at 15 degree C, whereas the healthy fronds 1.1×10 super (4). Twenty-six kind of colonies, 247 strains of bacteria, were isolated from diseased fronds, belonging to Moraxella, Achromobacter, Vibrio, Fluvobacterium, Acinetobacter and Pseudobacter, 2) Pinholes also occurred on the frond, probably caused by a harpacticoid copepod, Thalestris sp. 3) A gammarid amphipod, Ceinina japonica, invades the pith of the midrib through holdfast of thalli.

S 24/14

YU, L., WU, D. and Y. ZHANG
A new technology of recovering mannitol from the kelp steep by complexing mannitol with boric acid.
1981   13 pp
Mar. Fish. Res., no. 2, 95–107

This paper presents a new processing technology of recovering mannitol from the solution in which the kelp, Laminaria japonica is steeped. The process is the application of the principle that the mannitol-boric acid complex can be retained by the strong basic resin, and consists of concentrating and separating mannitol from the steep and purifying the mannitol will be doubled comparing with that of the conventional process and the coal consumption will be greatly reduced.

S 24/15

EDWARDS, P., BOROMTHANARAT, S. and D.M. TAM
Seaweeds of economic importance in thailand. Part 1: Field survey; Thai government statistics and future prospects.
1982   10 pp
Bot. Mar., vol. 25, no. 5, 237–246

Thailand is a net importer of seaweeds and seaweed products on Government statistics, but has the potential to be a net exporter of these commodities. Seaweeds were found to be relatively unimportant in the Thai diet since they are consumed in only small quantities, by coastal people. Seaweed cultivation as a source of phycocolloids should be undertaken, since Government statistic indicated the import of agar and algin in rapidly increasing amounts. Populations of Gracilaria, a source of low grade agar which appeared to comprise the bulk of the imported agar, were found in several parts of the country, although evidence was presented of a decline in their abundance in recent years. Remaining population should be used as seed for the establishment of Gracilaria farms.

S 24/16

YOKOYAMA, M. and Y. SANBONSUGA
On a seasonal variation in nitrate-N content of Laminaria during forced cultivation.
1979   6 pp
Bull. Hokkaido Reg. Fish. Res. Lab., no. 44, 67–72

Laminaria augustata, L. religiosa and 4 local forms of L. japonica were cultivated on ropes hung from a raft settled in the sea in Hakodate, whereby seasonal variation in nitrate-N content during the growth of plants was determined. The content reached maximum in March, except L. augustata, which showed the maximum in February. Significant differences in the content were recognized also among the local forms. As for the local forms, the one collected from Date facing on Uchiura Bay was preminently high in the content while L. augustata was low, in this characteristic they may resembled their mother plants growing in the home habitats.

S 24/17

RYTHER, J.H., CORWIN, N., DEBUSK, T.A. and L.D. WILLIAMS
Nitrogen uptake and storage by the red alga Gracilaria tikvahiae (McLachlan, 1979).
1981   9 pp
Aquaculture, vol. 26, nos. 1–2, 107–115

Nitrogen-starved plants of the red alga Gracilaria tikvahiae (McLachlan, 1979) assimilate ammonium-nitrogen very rapidly, doubling their total tissue nitrogen content in 8 h or less. Uptake of nitrate-nitrogen is less rapid. Ammonium uptake is initially the same in the dark as in full sunlight, but light-expose seaweeds continue to assimilate the nitrogen longer. N-starved plants soaked a full nutrient medium including NH sub(4) super(+)-N for as little as 6 h an returned to unenriched flowing sea water will grow at non-nutrient-limiting rates for as much as 2 weeks before they again become nutrient-deficient and their growth rate declines.

S 24/18

SMITH, I.R. and R. PESTANO-SMITH
A fishing community's response to seaweed farming.
1980   2 pp
ICLARM Newsl., vol. 3, no. 3, 6–8

The transition of a fishing community of Hingotanan, Philippines, from almost exclusive dependence on capture fishing to extensive involvement in seaweed (Eucheuma species) farming is described.

S 24/19

UKTOLSEJA, J.C.B., AMIN, E.M., UKTOLSEJA, N.R.E., FATUCHRI, M. and N. BUDIHARDJO-NAAMIN
The report on the marine fisheries resources survey in the Eastern Waters of Central Celebes. Part 1.
1979   92 pp
Mar. Fish. Res. Rep., no. 2, 92 pp

A survey of fishery resources was carried out in the waters east of Sulawesi. The potential yield of pelagic fish was 57,172 tons and of demersal fish 11,200 tons. Exploitation of the pelagic resources could be increased by adding 62-10 units of 30 GT vessels or 25–43 units of 15–30 GT vessels. Studies on the distribution and biology of skipjack, Katsuwonus pelamis; yellowfish, Thunnus albacares, and eastern little tunas, Euthynnus affinis and Auxis thazard were carried out. Data on catch/effort are given for troll-lines and drift-gillnet. Troll line catches were dominated (95.2%) by skipjack. Oceanographic data for temperature, salinity and oxygen are reported. Exploitation of pearl-oysters, Pinctada maxima, in the waters of Banggai is in the developing stages. Seaweed culture, Eucheuma spinosum, using rafts has a good potential, but the marketing system must be developed to protect the fishermen from the middle-men. Shrimp culture could be developed by establishing new brackishwater ponds in the mangrove area.

S 24/20

ROSENBERG, G. and J. RAMUS
Ecological growth strategies in the seaweeds Gracilaria foliifera (Rhodophyceae) and Ulva sp. (Chlorophyceae): Soluble nitrogen and reserve carbohydrates.
1982   9 pp
Mar. Biol., vol. 66, no. 3, 251–259

The seaweeds Gracilaria foliifera (Rhodophyceae) and Ulva sp. (Chlorophyceae) were grown in an outdoor continuousflow system at both ambient incident light (I sub(0)) and 0.13 I sub(0). During the winter, both species accumulated substantial soluble nitrogen reserves (up to 1020 mu g-at N multiplied by g dry wt super (-1) in G. foliifera and 630 mu g-at N multiplied by g dry wt super (-2) in Ulva sp.). The rate at which these N reserves were depleted was proportion to the growth rate. Seaweeds grown at 0.13 I sub(0) had lower growth rates an higher levels of soluble tissue N than plants grown at I sub(0). During the spring-summer growing season, peaks in tissue N followed nutrient peaks in the ambient seawater. Ulva sp. had higher nutrient uptake and growth rates than G. foliifera and showed greater fluctuations in soluble tissue N. This may characterize opportunistic seaweed species with high biomass turnover rates.