This article outlines the development of commercial open- water algae farming in Zanzibar in a historic context, with special reference to actual events at the corporate level from the initiation of algae-farming to its present state. These events, which contain policies and intentions of implementation at the producer level, have an array of social implications for the algae-farming communities. The three aspects of these implications are delineated; (i) a changing mode of tenure rights of the farmed lagoon areas; (ii) a changing role for algae farmers, i.e. women; (iii) a qualitative change within the composition of indigenous productive activities, the latter being illustrated by a de- clining activity in agriculture. The article demonstrates the importance of the encounter between an indigenous liveli- hood system and infused incentives pertaining to divergent rationales of livelihood in socioeconomic development processes.
Digital library
-
-
Marine algal ecology today faces many of the same problems as ecology in general, e.g. lack of generality of experimental results, the difficulty of making long-term predictions, and an apparent lack of agreement as to what constitutes the proper or 'acceptable' way of doing this particular component of science. These problems, if real, affect marine algal ecology everywhere but, in different geographical areas, specific problems also occur; science in parts of Asia has some problems different from those in other parts of the world. Since its inception, research in marine algal ecology has been motivated by many factors, ranging from traditional needs, to curiosity, to survival, to new technology, and economic needs. Each of these has shaped the questions that have been asked by, and the level ofsupportsociety has been willing to supply to, ecology. For example the requisites oftradition pushed marine ecology to ask questions about food and ceremonial biota, and our fears today about loss of biota are pushing for answers to questions about the means of preserving biodiversity. The limitations of many marine ecological studies have been pointed out by different individuals. Their comments have been valuable in forcing us to examine what we are doing as marine ecologists, and how we are doing it. Ecology, and marine algal ecology with it, has been accused of carrying out small-scale studies that have no greater generality than the sites at which the studies were done, and of using statistical procedures that are wrong or inappropriate; also, there is disagreement within the ecological community of how to correct for these 'faults'. Some of the problems arise due to the nature of our particular science, e.g. working with organisms with differing genetic makeup and sensitivity of experimental results to small changes in initial conditions. Other problems are more likely due to the individuals doing the science, e.g. an inability to be an 'expert' on all areas of knowledge required for a modem ecologist (taxonomy, experimental design, data analysis, etc.), and perhaps an unwillingness to recognize that in some instances different methods of data analysis are applicable and valid. As ecologists, we must come to grip with these problems, both for the sake of our science, and for our own sake as practicing ecologists.
-
Kappaphycus and Eucheuma species have been successfully cultivated in Southeast Asia since the early 1970s. The increasing global demand for carrageenan in processed foods and thereby the need for industrial-scales of biomass to be provided to feed an extraction industry, exceeded wild stock availability and productivity and commercial demands could only be achieved through extensive cultivation of selected carrageenophytes. This unprecedented situation led to the introduction of carrageenophyte species and cultivars around the world; combined production of Eucheuma and Kappaphycus is one of the largest for seaweed biomass in the world.
The activity of, and economic benefits accrued from, seaweed farming are indeed responsible for significant changes in rural, coastal communities in a number of important countries. Such activities generating new activity and income are often the only source of cash to some of the farmers. However, in spite of the enormous size and value of the industry the techniques applied to cultivation of carrageenophytes has remained almost unchanged in the commercial farms. Seedlings (or vegetatively propagated fragments of older, larger, mature thalli) are still most commonly planted along ropes held in various configurations, in most of the major production centers, e.g. mostly classified as simple stakes in the ground (off-bottom planting to floating rafts of various design). Some technological developments have been made in Brazil and India with the implementation of tubular nets for planting, which allows a degree of mechanization on the farms; both countries are developing mechanical harvesters. Further to co-production of biomass and harvesting, the drying process is still a limiting problem for production, and drying costs are high, in countries with high rainfall, this segment of the process is discussed in detail by Ali et al. Chap. 8). Diseases such as “ice-ice” and blooms of epiphytes and endophytes (see Chap. 6 by Loureiro et al.), as well as present and impending climate change effects (see Chap. 7 by Largo et al.) are also very big challenges.
In general, the production of carrageenophytes in tropical and sub-tropical regions is very dependent on the weather: as in prevailing conditions during the dry and wet seasons or surface seawater temperatures (SSTs) during “cold” winters and/or “hot” summers. For the future, efforts need to be made to increase the productivity and resistance of the selected strains of carrageenophyte seedlings against environmental instabilities.
-
The economic value of seaweed G. verrucosa depends on the content of the agar it has. Cultivation Gracilaria verrucosa generally use inorganic fertilizers that are not environmentally friendly, inorganic fertilizer is not a wise step considering the recent increase in consumers who want a product that is free of pesticide residues. The purpose of this study was to analyze the optimal dose of vermicompost fertilizer to produce high quality of agar rendement, viscosity and gel strength seaweed Gracilaria verrucosa. From the result of the research, it was found that the quality of agar rendement, viscosity and gel strength were normal and homogeneous distribution (p0,05). Then the ANOVA test showed that the fertilizer treatment gave a significant effect on the quality of agar rendement and viscosity (p 0,05). The highest level of viscosity and rendement of Gracilaria verrucosa seaweed was found in treatment A and the lowest in treatment F (control). The highest level quality of agar gel strength Gracilaria verrucosa was found in treatment F compared with other treatment.
-
Seaweed farms have the capacity to grow huge amounts of nutrient-rich food, and oysters can act as an efficient carbon and nitrogen sink. For decades environmentalists have fought to save our oceans from the perils of overfishing, climate change, and pollution. All noble efforts -- but what if environmentalists have it backwards? What if the question is not how to save the oceans, but how the oceans can save us?
That is what a growing network of scientists, ocean farmers, and environmentalists around the world is trying to figure out. With nearly 90 percent of large fish stocks threatened by over-fishing and 3.5 billion people dependent on the seas as their primary food source, these ocean farming advocates have concluded that aquaculture is here to stay.
-
The aim of this study was to determine the impact of sea urchin grazing ( Echinus esculentus) and canopy shading on the recruitment of the kelp Laminaria hyperborea in mid-Norway. A spatially variable distribution of sea urchins was observed, and recruitment processes were studied both after disturbance, caused by kelp harvesting removal of the canopy kelps, and in pristine kelp forests. The combination of sea urchin density and the density of canopy-forming kelps had the strongest influence on the density of small kelps in pristine kelp forest, suggesting that both grazing from sea urchins and shading from the canopy contributed to the mortality of small kelps. High densities of small kelps ( > 20 m(-2)) were only found in pristine kelp forest together with <= 6 canopy-forming kelps m(-2) or < 3 sea urchins m(-2) on average. However, within the observed range of sea urchin densities these had no effect on the density of large, canopy-forming kelps. Large L. hyperborea were apparently not subject to grazing. In addition, only a small number of surviving kelp recruits was needed to maintain the density of canopy-forming kelps, as L. hyperborea specimens may survive many years. These conditions result in high stability of the kelp forest. A different picture was seen after kelp harvesting, when high recruitment and survival of recruits are the conditions for rapid restoration of the kelp vegetation. After removal of the canopy-forming plants, the kelp recruits were temporarily released from high density-dependent mortality due to shading. Some influence of sea urchin grazing on the density of recruits was observed, but this was small compared with the strong canopy effect. However, the accumulated impact of grazing during a period of time had a strong overall effect on the regrowth of kelp. After 2.5 years the accumulated biomasses at the harvested stations were strongly related to average sea urchin density, and a density of between 4 and 5 sea urchins m(-2) resulted in very little biomass accumulation. This suggests that the L. hyperborea kelp forest vegetation has a high degree of stability, but shows less resilience after disturbance, when exposed to moderate sea urchin grazing.
-
The wholesale price of farmed salmon in local fish markets showed higher prices before the tsunami in 2011. Though farmed coho salmon started being landed again by the support of national funding in 2012, the price of the farmed salmon slumped. A higher price is necessary to maintain the farming facilities for management. This paper aims to clarify the causes of the price drop of Sanriku coho salmon and the issues in the reconstruction process of coho salmon aquaculture. The most important cause of the price drop of Sanriku coho salmon was that consumersʼ purchasing patterns changed from Sanriku coho salmon to imported salmon due to the lack of Sanriku coho salmon in 2011. We hope to supply fresh Sanriku coho salmon at prices between imported fresh Atlantic salmon and frozen rainbow trout in consumer markets. It is necessary to improve the traditional aquaculture system and to develop brand value for Sanriku coho salmon. Sales promotion is expected to drive the price of the fresh coho salmon up to a fair level.
-
A PDF Power Point on "The Bullseye Fuel - BAL and its macroalgae-based biofuels - Biofuels Digest"
-
Meat consumption is rising worldwide, but production involves vast amounts of energy, water and emissions. At the same time, wild fisheries are declining. Aquaculture could become the most sustainable source of protein for humans.Fish farming already accounts for half of global seafood production. Most of it is done along coastlines, which creates substantial water pollution.
Large, offshore pens that are anchored to the sea floor are often cleaner. Those farms, other new forms of aquaculture, and practices that clean up coastal operations could expand aquaculture significantly. Questions remain about how sustainable and cost-effective the approaches can be.
-
Biofuels such as biodiesel and bioethanol, synthesized via microalgal bioprocess engineering, could be a major contributor to the purview of sustainable energy in the foreseeable future. In contrast to other biomass feedstocks like corn, sugar crops, and vegetable oil, microalgae display a number of significantly superior benefits as a raw material for biofuel manufacturing. This includes an enhanced metabolic rate of biomass production, subsistence of diverse microalgae species with sundry biochemical profiles, prospects for carbon dioxide sequestra- tion, and either limited or near absolute monopoly from the perspective of food production modalities and logistics. However, attributing to a wide range of factors, for instance the insipid characteristic of microalgal cultures, and the fact that microalgae cells possess trivial sizes, the process of biomass production and sub- sequent conversion into biofuels become prohibitively expensive. As a conse- quence, from an economic outlook, the large-scale production of biofuels from microalgae achieves a somewhat less appealing status, compared to the other biomass types and sources. The current chapter delivers an outline of the bioe- conomy analysis for microalgae-derived biofuels. In addition, case studies on microalgal biofuel production are presented along with cost estimations and the necessary strategies to augment its commercial viability.
Pages
Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
Funding for this web portal is provided by the World Wildlife Fund and the University of Hawaii-Hilo.