As the world population is drastically increasing, industrialization and urbanization are also increasing. Eventually, environmental pollution is increasing, and the amount of arable land is decreasing. Water scarcity is becoming a challenge throughout the world in that nearly half of the world population will experience water shortage. The rate of water utilization increases at twice the rate in the world as compared to the increases in the human population. This proves that water is no longer to be considered an infinite source. Sustainable use of agricultural and environmental sources will optimize the skills and use of technology to achieve long-term stability of agricultural enterprise, environmental protection, and consumer safety. Sustainable agriculture and environment could be achieved through management strategies which help the producer select hybrids and varieties, soil conserving cultural practices, soil fertility programs, crop rotation, weed, pest and disease management programs, strategic use of animal and green manures and use of natural or synthetic inputs in a way that poses no significant hazard to human beings, animals, or the environment. Sustainable agriculture and environment incorporates heathy environment and economic profitability along with providing food needs to the society. The Food and Agricultural Organization reported that more than half of the water sources were used for irrigation in the world. Industrial and municipal usage of water comes after irrigation. Therefore, water demand could further affect the amount of water utilization in agricultural sectors. This may cause water crisis in and among countries. To deal with this potential water crisis, new water management approaches and strategies are required for all sectors, in particular, the agricultural sector. Application of new technologies (precision agriculture) help to increase the sustainable usage of water sources in agriculture while enable higher crop production. Excess utilization of fertilizers and pesticides causes contamination of surface water and groundwater sources. Use of salt-rich irrigation waters increases the salinization. Water content and salinity level have a vital effect on both quality and quantity of agricultural crops. Therefore, necessary sustainable steps should be taken to handle all these issues. This conference brought together a large number of researchers, students and professionals from all over the world to discuss the technological developments and applications on sustainable agriculture and environment. The main topic areas that covered were social and economic aspects of environment, biology and agriculture, sustainable development, tropical agriculture, biodiversity, biotechnology, horticulture, plants, animal production, climate change, environment, local ecological knowledge, water management, soil conservation, agriculture social economics, integrated pest management, food security, and other related agricultural and environmental issues. All the abstracts and selected papers are now available in this “proceeding book”. The editors would like to thank all the attendees who brought their generous contributions to the organization of another successful conference. Lastly, we would like to thank the organizing committee members for their time and efforts dedicated to making 5th ICSAE a successful event.
Digital library
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Eucheuma seaweed culture was initiated and developed in the Philippines in the late 1960's by Dr.Maxwell Doty's team. Today, Eucheuma industry has become one of the most important fishery export industries of the Philippines. Contrary to the Philippines where seaweed farming is widespread and well developed, the Pacific island countries have experienced great difficulties, both of social and economic nature in establishing the cultivation of carrageenophytes. However, the great potential of seaweed farming in rural development has motivated Pacific countries to look at the seaweed industry very seriously.
The first trial of Eucheuma culture in the South Pacific was carried out in Fiji in the mid 1970's with imported seedstock from the Philippines though this trial was not successful. In 1977 another trial of Eucheuma culture was carried out by Dr. M. Doty at Christmas Island, Kiribati. The seedstock of Eucheuma was brought from Hawaii, originally having come from the Philippines. The seed was afterward introduced to Tarawa from Christmas Island in 1981. Then, to Tonga from Tarawa in 1982, to Fiji from Tonga in 1984 and to Solomon Islands from Fiji in 1987. The first commercial shipment of 2 mt dried Eucheuma from the region was made in 1984 from Tarawa. In the region Eucheuma is currently exported from Fiji, Kiribati and Federated States of Micronesia. Culture trials are being or have been undertaken in Solomon Islands, Tonga, Tuvalu and French Polynesia.
In 1986, Fiji became the major Eucheuma growing country in the region, with 200 mt of dried Eucheuma exported in 1986 and 277 mt in 1987. However, in 1988, Eucheuma culture was totally deteriorated because of the political change that happened in the country and the sudden withdrawal of the sole Eucheuma buyer from New Zealand.
In order to overcome the marketing crisis in Fiji, most of Eucheuma buyers were contacted world-wide through the FAO network. As a result, the FMC Corporation Marine Colloids Division visited Fiji in the late 1988 and showed interest in trading the Fiji Eucheuma.
In the Pacific island context, the culture of seaweed could be beneficial for rural development. Owing to the low technology involved in farming and the small initial capital investment required, seaweed culture holds considerable promise for developing exports, providing employment, as an alternative source of income for rural fisherman and for exploiting extensive reef and lagoon areas suitable for mariculture purposes. Fiji started an arrangement of restoration programme of Eucheuma culture in 1989.
During the Second Technical Sub-committee Meeting of the Forum Fisheries Committee 16th Meeting held at Majuro in April 1989, a special meeting on seaweed culture development was organized among the Eucheuma growing and interested countries. In this meeting the countries emphasized the need for studies on marketing of dried Eucheuma, production economics and development of other potential seaweeds culture.
In response to this regional need together with aiming at promotion of Eucheuma culture in Fiji, the SPADP organized a workshop on seaweed culture and marketing for both the region and the country of Fiji, in association with the Marine Colloids Division and the Fiji Fisheries Division. The main objectives of this workshop were to:
Encourage Eucheuma seaweed culture in the Pacific region by describing and practically demonstrating appropriate culture techniques including introduction of a newly developed culture practice;
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Demonstrate baling processes and explain product quality control for the export market;
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Provide opportunities for the exchange of up-dated information, and discussion on the present situation, trends and constraints of international seaweed culture and marketing with international experts and marketing authorities.
We wish to thank the regional participants who prepared country reports, all the people of Kiuva village who accepted our field tour, for the warm-hearted and unforgettable hospitality shown to the participants, the staff of the Fiji Fisheries Division who arranged for the installation of the baling machine, the University of the South Pacific who kindly hosted the workshop, and the Marine Colloids Division's staff and the invited experts for their invaluable contribution.
It is the workshop organizer and the editor's hope that the proceedings of this workshop will be a valuable resource for both those interested in setting up seaweed farms and government officials who need to assess the prospects for seaweed farming in their countries.
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Culture of seaweeds is practiced since ages in countries such as Japan, Ctiina and Korea. Seaweed cultivation is an industry in Japan as a part-time avocation for land farmers and fishermen. The seaweeds cultured mainly in these countries are Porphyra, Undaria, Laminaria, Enteromorpha and Monostroma. In India seaweed culture is yet to develop on commercial lines. While the demand for these seaweeds is for food purposes in foreign countries, their demand in India is for the extraction of two phytochemicals namely agar-agar and algin. In recent years many factories manufaauring these chemicals have come up in India as a consequence of which the demand for the agarophytes and alginophytes has gone up. In order to maintain a continuous supply of this raw material to the industry, methods to augment the supplies through culture practices have to be developed.
In recent years the Central Marine Fisheries Research Institute has been engaged in the cultivation of several economically important seaweeds such as Sargassum wightii, Twbinaria spp., Gracilaria edulis, G. corticata and Gelidiella acerosa which indicated great scope for cultivation. The production rate has been found to be 4.4 kg/m' in the case of G. edulis and 3 kg/m* in the case of G. acerosa in about 80 days for 0.30 kg and 1 kg of seed material introduced respectively. In the case of alginophytes the growth was not encouraging. These culture experiments were conducted by introducing small fragments of the seaweed into the twists of the coir ropes fabricated in the form of a S x 2 m net and tied to fixed poles in inshore waters. In the case of G. acerosa, the substratum along with the plant fragments was tied to the ropes.
The agarophytes thus grown can be processed further for extraction of agar-agar. The extraction could be done by a simple cottage industry method not involving any costly equipment. In the case of Gelidiella agar, freezing and thawing are required to remove the insoluble chemicals. A total of 90 tonnes of G. edulis can be obtained from 3 harvests in a year from a hectare area.
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The rapid development of modern society has resulted in an increased demand for energy and, consequently, an increased use of fossil fuel reserves, compromising the energy sector sustainability. Moreover, the use of this source of energy led to the accumulation of greenhouse gases (GHGs) in atmosphere, which are associated with climate change. In this context, European Union has established new directives regarding GHG emissions and the renewable energy use. Microalgae may have an important role in the achievement of these goals. These photosynthetic microorganisms have a high growth rate, are able to capture CO2, the biomass can be used to produce biofuels, constituting an undeniable economic potential. Microalgae may also be a source of low carbon fuel, being one of the most studied biofuels feedstock. They are considered a sustainable energy resource, able to reduce sig- nificantly the dependence on fossil fuel. They can grow on places that are unsuitable for agriculture, not competing with land for food production. The use of wastewater as microalgal culture medium will reduce the required amount of freshwater and nutrients, achieving simultaneously an effluent with low nutrient concentrations. An important step to increase the competitiveness (promoting simultaneously the environmental sustainability) of microalgal biofuels regarding fossil fuels is the optimization of culture parameters using wastewater as culture medium. Thus, this chapter aims to present the recent studies regarding the integration of wastewater treatment and microalgal cultivation for biomass/biofuel production.
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Atremendousincreaseinpopulationhasalsoledtoasignificantincrease in the demand for energy leading to search for alternatives which can match up with the current requirement quantitatively and also qualitatively as a green energy carrier. Fuels derived from algal biomass can be one of the potential alternatives, as microalgae possess higher nutrients, required lipids and CO2 uptake capacity and can be grown quickly on nonarable land throughout the year without their inter- ference in food supply chain. The quantum of biodiesel produced from microalgae can be about 10–20 times higher than that obtained from terrestrial plants. Microalgae also help in reducing global warming by capturing CO2. The cost of production of biofuels from microalgae is the current setback which can be over- come by taking into consideration a biorefinery approach which can give multiple products with same expenditure as well as using some process intensification approaches. Process intensification plays a major role in reducing the cost and also can lead to use of less quantum of materials and lower operating temperatures. The present chapter will focus on analyzing the process intensification aspects applied to biofuels production from microalgae. The initial sections will cover the details of the types of microalgae and their harvesting techniques, followed by the discussion on the different approaches used to extract bio-oil from microalgae, and then the production of different biofuels. Intensification can be applied to both the extraction and the actual reaction for production of biofuels. The chapter will also focus on the mechanism of intensification using different approaches such as ultrasound, microwave, ultraviolet, and oscillatory baffled reactors. An overview of the litera- ture will be presented so as to give guidelines about the possible reactor designs and operating parameters also highlighting the process intensification benefits that can be obtained. Overall, the work is expected to bring out critical analysis of the different approaches and the expected benefits due to the use of process intensifi- cation also enabling understanding of the reactor designs and operating parameters.
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Sea cucumbers cultured in ponds or in the sea are potentially lucrative commodities, but their export value can be gained or lost through the processing used. The gutting, water temperature, cooking times, handling and drying techniques should all be carefully controlled in order to achieve the highest grade possible for export. Farmed sea cucumbers may have thinner body walls than wild animals, but have the advantage of being of consistent size, can be processed immediately after being removed from the water, and can be processed in bulk. Processors must understand the preferences of overseas importers, as desired processing approaches may vary. The use of fuel for boiling sea cucumber to make beche-de-mer can be an ecological concern. Body organs and muscle bands may offer new products for value-adding of cultured sea cucumbers. Likewise, markets are more open to fresh and canned product. Training and providing guides in the best methodologies and new market opportunities to processors present fruitful scope for improving the cost-effectiveness of farming and sea ranching tropical sea cucumbers.
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The publication describes the production, properties and main applications of the three major phyco-colloids extracted from seaweed: agar, alginate and carrageenan. There is also a supplementary chapter on the preparation and marketing of seaweeds as food. Although this is based mainly as Japanese experience it is included in order to encourage increased consumption of seaweeds as human food.
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The current work aimed to develop a cultivation method for macroalgae that can be applicable and economically profitable in the Atlantic Ocean. An offshore long-line macroalgal cultivation rig was designed by Ocean Rainforest Sp/f, tested in the Faroe Islands from 2010, and found suitable for cultivation in exposed and deep- water locations (water depth > 50 m). The economic risk related to lost cultivation structures was hereafter considered to be low. Saccharina latissima and Alaria esculenta were cultivated in commercial scale (5 km of growth lines). A high cost of seeding material and cost of deployment was reduced by testing multiple partial harvesting. Four non-destructive harvests were carried out in a two-year growth period without re-seeding of lines. In total, 3.2 t dry weight (dw) biomass was harvested and sold to customers within the food and cosmetic industries. The productivity was 1437.5 kg dw ha−1 yr−1 (including handling space). The 10-meter vertical growth lines had an average yield of 0.29 kg dw m−1 per harvest and four partial harvests were made over a 2- year period. An economic analysis showing the cost structure of important aspects of offshore macroalgae cultivation was conducted. The total cost per kg dw of cultivated S. latissima decreased when the number of possible harvests without re-seeding was increased (from € 36.73 to € 9.27). This work has demonstrated that large-scale kelp cultivation is possible using multiple partial harvesting in the Faroe Islands, and highlighted the need for further innovation to lower the cost per unit macroalgal produced.
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Green seaweed Ulva lactuca harvested from the North Sea near Zeeland (The Netherlands) was characterized as feedstock for acetone, ethanol and ethanol fermentation. Solubilization of over 90% of sugars was achieved by hot-water treatment followed by hydrolysis using commercial cellulases. A hydrolysate was used for the production of acetone, butanol and ethanol (ABE) by Clostridium acetobutylicum and Clostridium beijerinckii. Hydrolysate-based media were fermentable without nutrient supplementation. C. beijerinckii utilized all sugars in the hydrolysate and produced ABE at high yields (0.35 g ABE/g sugar consumed), while C. acetobutylicum produced mostly organic acids (acetic and butyric acids). These results demonstrate the great potential of U. lactuca as feedstock for fermentation. Interestingly, in control cultures of C. beijerinckii on rhamnose and glucose, 1,2 propanediol was the main fermentation product (9.7 g/L).
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Data on fractionation and depolymerization of the matrix ulvan polysaccharides, and studies on the biological activities on skin cells, are very scarce. In this work, crude ulvans were produced by using EAE (enzyme-assisted extraction) and compared to maceration (an established procedure). After different fractionation procedures—ethanolic precipitation, dialysis, or ammonium sulfate precipitation—the biochemical composition showed that EAE led to an increased content in ulvans. Coupling EAE to sulfate ammonium precipitation led to protein enrichment. Oligosaccharides were obtained by using radical depolymerization by H2O2 and ion-exchange resin depolymerization. Sulfate groups were partially cleaved during these chemical treatments. The potential bioactivity of the fractions was assessed using a lipoxygenase inhibition assay for anti-inflammatory activity and a WST-1 assay for human dermal fibroblast viability and proliferation. All ulvans extracts, poly- and oligosaccharidic fractions from EAE, expanded the fibroblast proliferation rate up to 62%. Our research emphasizes the potential use of poly- and oligosaccharidic fractions of Ulva sp. for further development in cosmetic applications.
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