Digital library

  • FEASIBILITY STUDY ON FARMING, PROCESSING AND EXPORT OF EUCHEUMA (SEAWEEDS) LAAMU ATOLL MALDIVES

    The Seaweed Consultant was hired by the FAO to assist the Ministry of Fisheries and Agriculture (MOFA) through the Oceanographic Society of Maldives (OSM) in introducing the Eucheuma (seaweed) farming technology at Gamu Island, Laamu atoll, Maldives.

    Several prior attempts to introduce seaweed fanning in the Maldives had failed, mainly due to the problem of fish grazers. The farming technique used in the Philippines, Malaysia, Indonesia, and Tanzania (monoline system) could not be applied successfully in the Maldives due to the abundance of fish grazers which thrive in the lagoons.

    When the consultant arrived in the Maldives in February 1996 for his first one-month technical assistance, he brought a sample of the net-bag propagule holders which he had devised in the Philippines to counter problems such as grazer attacks and losses due to turbulent weather. The floating net-bag technique is described in detail in the project field document No. 2. The new technique eliminated also the tedious process of tying every propagule to the monoline, thereby saving a lot of labour cost. When he visited the test station for the Eucheuma at Gamu island, he observed that the plants were almost consumed by the grazers since the propagules were cultured using the monoline system. The remaining plants were untied from the monoline and then brought to another site where the current was good and where the water motion was consistent. The five kilograms of cottonii which were salvaged were planted, placing them in 10 net-bags at the rate of 1/2 kilogram/bag. The propagule line containing the 10 net-bags was installed in the water in the selected area. After 15 days, the plants recovered and showed a good growth rate, which was computed to be 3-4% daily.

    The seedlings in the net-bags were split continuously every month. Five hundred net-bags were procured to contain the rapidly increasing volume of seedstocks. By September, 1996, OSM reported that the seedling inventory was already 600 kilograms, requiring additional net-bags (35,000 pieces).

    At this time the plant growth had increased to about 5-6% daily, which means that the biomass was doubling every 10-15 days.

    In March, 1997, the Seaweed Consultant carried out his second one-month mission to evaluate the performance of the seaweed culture and to introduce the post-harvest technology to the project staff and workers.

    Author(s):

  • Feasibility study of Ulva sp. (Chlorophyta) intensive cultivation in a coastal area of the Eastern Mediterranean Sea

    Increasing biomass production yields is a critical challenge for macroalgae biorefineries. The continuous tumbling and mixing of free-floating algae through water or airflow has been shown to increase the productivity of algae in land-based cultivation systems. This approach has not been tested thoroughly in offshore cultivation. We report, here, a field feasibility study on the increase in green macroalga Ulva sp. growth rates in offshore cages, achieved by the combined effect of tumbling and mixing of the algae using influxes of water and air. The experimental system was tested in a shallow coastal area in central Israel, in the eastern Mediterranean Sea. A maximum daily growth rate of 19.2%, areal productivity of 33.72 g dry weight (DW) day−1 m−2, and volumetric yields of 37.78 g DW day−1 m−3, together with 38.47 ± 0.01% ash and 5.28% protein content on a dry matter basis were achieved in the cages with intensified cultivation in the first week of May 2017. Our study shows that cultivation with tumbling and mixing of biomass with air, and water exchange with the environment is a feasible method to increase Ulva sp. biomass productivity offshore.

    Author(s): Alexander Chemodanov, Arthur Robin, Gabriel Jinjikhashvily, Dror Yitzhak, Alexander Liberzon, Alvaro Israel, Alexander Golberg

  • Fatty acid profiles of marine red alga Gracilaria spp (Rhodophyta, Gigartinales)

    Species of Gracilaria from Gulf of Mannar were analyzed for their fatty acid composition. The major fatty acids such as myristic acid, myristoleic acid, palmatic acid, palmitoleic acid, stearic acid, oleic acid and linoleic acid were analyzed by gas liquid chromatography. The qualitative and the quantitative distribution of above fatty acids exhibited wide variation among the species of different habitat. The fatty acid content of the species collected from the same locality also showed quantitative variation depending on their distribution and the availability of light intensity to the particular species.

    Author(s): Fatty acid profiles, Marine red alga, Gracilaria

  • Farming the Waters for People and Food

    According to World Food Summit 1996, food security exists when all people, at all times, have physical and economic access to enough safe and nutritious food to meet their dietary needs and food preferences for an active and healthy lifestyle. In order to be food secure, the food should be available and affordable. For the more than a billion people who do not get enough regular, healthy food, ill health and a shorter life expectancy are real risks. Children, and especially very young children, who suffer from food insecurity will be less developed than children of the same age who have had sufficient food.

    Aquaculture offers a significant opportunity for improving food security and nutrition by providing nutritious, yes affordable protein to many millions of people worldwide. The increase in global population, gradual depletion of finite resources required form sustainable expansion and development of aquaculture poses threats to future fish global protein supply. Over and above, the impacts of climate change are also posing threats to sustainable aquaculture development thus requiring focused implementation of mitigation and adaptation strategies. Current paper describes how aquaculture is perceived to contributes to improving food and nutrition security and the mitigations required for overcoming climate change and other environmental challenges for maintaining sustainability of the sector. 

    Author(s): Rohana P. Subasinghe, j. Richard Arthur, Devin M. Bartley, Sena S. De Silva, Matthias Halwart, Nathanael Hishamunda, C.V. Mohan, Patrick Sorgeloos

  • Farming Seaweed in Kiribati: A practical guide for seaweed farmers

    Farming Seaweed in Kiribati: A practical guide for seaweed farmers

    Author(s): Antoine Teitelbaum

  • Farming Salmon: An Example of Aquaculture for the Mass Market

    Aquaculture products serve two broad market categories, namely, ‘niche’ markets and ‘mass’ markets. There are hundreds of different species produced in aquaculture, most of them niche-market species, that is, those produced in modest volumes and sold at relatively high prices to a limited number of people. Examples include various species of eels, flatfish, bass, grouper, snappers and bream. In general, at present costs of production, these species will not meet mass market value expectations and are not likely to be candidates for future, large-scale aquaculture expansion. In contrast, there are very few species that are produced on a scale large enough and at a cost low enough to be considered mass market items. Examples include some shellfish, carp, tilapia, catfish, and salmon.

    Author(s): John Forster

  • Farming of the seaweed Kappaphycus alvarezii in Tamil Nadu coast - status and constraints

    Kappaphycus alvarezii is one of the economically important red algae, which yields carageenan, a commercially important polysaccharide. Carrageenans are used in a variety of commercial applications as gelling, thickening, and stabilizing agents, especially in food products such as frozen desserts, chocolate milk, cottage cheese, whipped cream, instant products, jellies, pet foods and sauces. Besides, carrageenans are used in pharmaceutical formulations, cosmetics and industrial applications such as mining. Commercial cultivation of K. alvarezii originated in Philippines in the year 1960. Since then, countries like Japan, Indonesia, Tanzania, Fiji, Kiripati, Hawaii and South Africa have been cultivating this species on a large scale. In India, cultivation of this seaweed started at Mandapam on the south-east coast of India, during 1995–1997.

    Author(s): Johnson, B, Gopakumar, G

  • Farming of the Giant Kelp Macrocystis Pyrifera in Southern Chile for Development of Novel Food Products

    This study explores the potential cultivation of the giant kelp Macrocystis pyrifera (L.) C.A. Agardh in southern Chile, for the development of novel food products. The study demonstrates the importance of considering the collection site of the parent sporophytes for successful cultivation. This study also shows that the ropes must be seeded with 10,000 to 40,000 spores ml−1, depending on the culture method used. We also demonstrated that under environmental conditions in southern Chile, the seeded ropes must be put at sea at the latest during autumn (April) in order to reach the harvesting season in December. However, several other management aspects must be considered to improve the quality of the product. Our final estimation indicates that over 14.4 kg m−1 of rope (fresh weight) can be produced and from this total production, over 70% can reach the quality to produce different food products that are already being introduced in oriental countries. The remaining 30% can be used for abalone feeding and is also available for the organic fertilizer industry located in Chile.

    Author(s): Carlos Cáceres, Roberto Marcos, Alejandro Santibañez, Verónica Muñoz, Tomás Correa, Alfonso Gutierrez, Alejandro H. Buschmann

  • Farming of Hypnea valentiae (Turner) Montagne at Minicoy Lagoon (Lakshadweep)

    The red alga Hpea valentiae (Turn.) Mont. is one of the carrageenan producing seaweeds. Experiment was canied out at Minicoy Lagoon of Lakshadweep during 1998 to fmd out the feasibility of farming of H. valentiae. Two sites were selected in the intertidal zone of Minicoy lagoon, namely South end and Fisheries Jetty and farming was carried out in three seasons @re monsoon, monsoon and post monsoon). Single line bottom coir rope method was adopted for farming. The vegetative fragments of H. valentiae collected from wild were inserted between the twists of long coir ropes. Both ends of the ropes were tied to the coral stones and introduced in the intertidal waters of the lagoon. During the first harvest maximum yield of 6 fold increase was obtained in 37 days and in the second harvest during monsoon months 25 fold increase was recorded in 40 days. Large scale farming of H. valentiae without causing any damage to the lagoon ecosystem by adopting single bottom coir rope method may be taken up by the fIshmen during the lean fishing season.

    Author(s): Mohamed, Gulshad

  • Farming Deep, but Aiming High. Economic Incentives and Ecological Imperatives in Open Ocean Fish Farming

    Offshore fish farms are highly capital intensive, and operational expenditures are inherently greater than for conventional inshore cage culture systems. Research and development costs offshore
    are exorbitant, and the risks to investment are very real, and uninsurable. To attract investment, recapture these higher costs, and return an appropriate profit, open ocean ventures must look to a willingness on the part of the consumer to pay a premium for open ocean grown products.

    Author(s): Neil Anthony Sims

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