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  • In response to an increasing interest in sustainable aquaculture among governments and international donors, the Food and Agriculture Organization of the United Nations (FAO) and the WorldFish Centre undertook a review of how aquaculture is targeted in sub-Saharan Africa as a first step in the identification of appropriate extension approaches and production strategies that would suit the various technology user-groups. Representatives of senior fisheries management agencies from nine countries in the region met to discuss progress, opportunities and key constraints to aquaculture development.

    Through a series of presentations, working group sessions and plenary discussions, broad consensus was achieved on the way forward for African aquaculture. In an effort to realize the goals of aquaculture, an attempt was made to develop a set of practical guidelines that can be used by national governments to insure that the major constraints are being addressed and that the major opportunities for aquaculture are capitalized upon to increase the contribution of aquaculture to food security and economic growth.

    Author(s): John Moehl , Matthias Halwart, Randall Brummett
  • WGEIM met at the University of Rhode Island from 24–28, April 2006. The meeting was attended by 11 members and one observer from six countries. Six terms of reference were addressed by the group and are summarised below.

    The WG continued to develop a series of documents concerning risk analysis of the consequences of genetic interaction between farmed fish and conspecific wild stocks, as part of a joint project with GESAMP WG31. The documents consist of an introductory paper describing the risk analysis approach, and case studies of five non-salmonid aquaculture species (cod, halibut, sea bass, sea bream and turbot). The WG agreed that the papers were nearing the standard and completeness necessary for submission for peer reviewed publication. The WG recommended that the documents be completed intersessionally and submitted to an appropriate journal.

    The WG continued to review existing (EU) legislation or proposed legislation and assess the impacts of the legislation on mariculture activities. Under the Water Framework Directive, no obvious mariculture impacts were highlighted based upon the implementation activities within the intersessional period. Proposed legislation is the European Marine Strategy (EMS), the Strategy for Sustainable Development of European Aquaculture and amendments to the EU Data Collection Regulation all of which might have some impacts on aquaculture activites. The group continued to investigate the applicability of sustainability indicators for aquaculture. SI’s are different from “impact” indicators in that they are more comprehensive, including considerations of not only environmental but also social and economic sustainability. Sustainability indices (SIs) are needed by aquaculture resource managers who must sort through large amounts of scientific information and make numerous environmental decisions. SIs offer a means to prioritize those aquaculture systems most in need of immediate management attention and allow scarce management assets to be applied in the most costeffective manner. SIs are also valuable for owners of seafood businesses who wish to procure “sustainable seafoods” for this rapidly growing consumer movement. The group considered and evaluated the current status and suitability of SIs for mariculture and selected a suite of SIs that are simple, flexible and cost effective. The group used a matrix approach that maps “sustainability trajectories” and was applied to salmon farming in New Brunswick, Canada and Norway. A number of recommendations were forthcoming from this term of reference. WGEIM will continue to refine the sustainability trajectories approach using the traffic light system of the UK and Canada and apply this example to salmon and shellfish aquaculture farming systems.

    Integrated Multi-Trophic Aquaculture (IMTA) represents a global aquaculture sector of growing interest and potential development in the world. Although much of this interest has been expressed through ongoing research initiatives, there has been some movement towards commercialization through large-scale testing of these opportunities. The evolution from monoculture aquatic food production systems to integrated, multi-species systems is envisioned as a shift towards a sustainable approach, and one that has seen parallel developments occur in the terrestrial food production industries.

    Results of research programs in North America and Europe would suggest that IMTA has high commercial potential, but that there are still some challenges remaining in terms of R&D, regulatory framework development, and product acceptability. Experimental and pilot-scale systems are providing growing evidence that there are low-level risks associated with contaminant transfers among Integrated Aquaculture components, and that these periodic risks are manageable in terms of husbandry practices and with appropriate regional/international regulatory requirements for seafood inspection. The legal frameworks that currently apply to the aquaculture industry, in most jurisdictions, are considered sufficiently flexible as to accommodate the development of Integrated Aquaculture systems and it is clear that the environmental, economic and social benefits associated with this sustainable approach to aquatic food production outweigh the risks.

    The potential advantages and disadvantages of integrated mariculture, based on our assessment of the environmental, social and economic considerations for this sector were presented. In addition, number of information gaps were highlighted and research and development initiatives were recommended.

    One of the obvious short-comings of research to date is that studies on substitution of fish meal and fish oil have been mutually exclusive. Many of the promising results from substitution of fish oils with plant oils have been due, in part, to inclusion of high levels of fish meal in the same diet. The fish meal provides some of the essential fatty acids that would have normally been provided directly by the fish oil. Although other novel sources of essential fatty acids are available, they must become more economical before they can sustain the needs of the aquaculture industry. Nevertheless, great advances in reducing, if not eliminating, the reliance upon wild fisheries resources for aquaculture feed ingredients are being made.

    The primary conclusion is that during the intersession WGEIM will carry out a review and evaluation of recent advances on alternative sources of lipid and protein to fish oil and fish meal in aquafeed. It is proposed that WGEIM review a draft manuscript at the 2007 meeting that is to be submitted for publication in a peer reviewed scientific journal.

    To date, the interaction of mariculture with exotic species and more specifically unintentional species introductions has received limited attention. This is despite the fact that exotic species are having significant impacts on the aquaculture industry worldwide and more particularly for the shellfish aquaculture industry.

    The importance of bivalve culture in the promotion and transfer of exotic aquatic species as well as the importance of these exotic species to bivalve culture and the environment. Specifically, we focused on exotic species with an emphasis on those that become invasive and nuisance. Management implications and mitigation strategies are also addressed. It should be noted that the majority of the existing literature addresses the issues as they relate to oyster culture, probably because this appears to be the single greatest vector for all types of introductions (planned or otherwise) in bivalve aquaculture. There is little published information about other bivalve species with respect to their role as vectors for exotic species.

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  • This report brings out the marine algal resources of the Tamil Nadu coast as the outcome of the Marine Algal Survey undertaken during 1971-76 as a co-ordinated project by the three organisations a Department of Fisheries, Government of Tamil Nadu, The Central Marine Fisheries Research Institute and the Central Salt & Marine Chemicals Research Institute. The survey was conducted both intensie ely covering all the marine algal species and extensively covering a wide coastine in the intertidal and sub - tidal beds. Though found in moderate quantities in comparison with the rich seaweed in the world,the marine algal resources estimated now are found to be quite considerable.

    In spite of the fact that some of the economic seaweeds have been commercially exploited from this region,there is still a possibility for greater harvesting and utilization of the brown algae particularly the species of Sargassusm and Turbinaria for alginate industry and the species of Gracilaria for agar industry in our country, However,resources of Gelidiella aceros need to be conserved. The scope for harnessing other available marine algal resources and their proper utilization, say for extractives, fertilizer, etc. are indicated .

    Author(s): K. Subbaramaiah, K. Rama Rao, Shri M. R. P. Nair
  • The importance of seaweeds as a marine resource has recently been emphasized due to the increasing demand for them as food and raw materials in the manufacture of industrial colloids, e.g. agars, carrageenan, and alginates which find varied uses in industries. In addition, the production of seaweeds through culture is now recognized as a very productive alternative source of livelihood and employment especially in developing countries in tropical Asia where a large portion of the shallow coastal fishery resources have been or are being depleted. With some exception, the present seaweed production in the tropics comes from the harvesting of wild stocks which if not regulated can result to the depletion of these stocks. Thus, it is necessary that culture and management of local stocks should be developed for the economic species to enhance and maintain their productivity. 

    The farming and gathering of economic species of seaweeds are labour-intensive form of activities which can help increase employment opportunities among the coastal communities and thus play an important role in enhancing their socio-economic conditions. The general ecology and productivity of shallow subtidal areas have been shown to greatly improve upon the introduction of seaweed farming. Additionally, the introduction of a management scheme for the gathering of local stocks shall also help conserve them. 

    The training of fishery extension workers, farm managers, and future seaweed farmers in the practical methods of culturing economic speices on Eucheuma, Gracilaria and Caulerpa, will promote further expansion of seaweed farming; on the inventory and assessment of local stocks of useful seaweeds shall promote and enhance the productivity and conservation of these species. It is for these reasons that this regional training was organized and implemented. 

    This training course was designed to develop and promote qualified expertise in seaweed farming to help in food production, provide cash crops and open new alternative employment to enhance the socio-economic welfare of coastal communities as well as offer practical training on seaweed farming and management of natural stocks of economically important seaweed species; improve technical knowledge about seaweeds and acquire practical skills in seaweed farming techniques, processing and marketing. 

    The course consisted of lectures and field training on the culture of Eucheuma, Caulerpa and Gracilaria, assessment and rational utilization of natural stocks of ecomomic species such as Sargassum, post-harvest and quality control of the produce and field study visits to existing farms. Basic lectures on the biology and ecology of seaweeds as well as methods on the identification and preparation of seaweed materials for research were also included as background information. 

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  • Algae remain an attractive target for bioenergy applications over the longer term because of their high photosynthetic efficiency. However, near-term prospects for primary algae-based energy/fuels production remain poor due to the cost of cultivating and harvesting algae. While there has been substantial technical progress on algae-based bioenergy production in recent years, persisting low fossil fuel prices are causing the algae-based industry to shift its focus from biofuels/bioenergy products to higher value (non-fuel/energy) products that can be profitable today. Ultimately, the vision is that algal biomass-based co-products will provide the additional revenue needed to reduce the net cost of producing algal-based biofuels. As such, a biorefinery approach that enables multiple high-value products to be produced will be essential to fully valorize algal biomass and enable bioenergy coproduction. To accelerate implementation of algae-based production, progress in minimizing the energy, water, nutrients and land use footprints of integrated algal-based operations needs to be a primary objective of future larger scale demonstrations. This presentation will summarize findings of a recently completed IEA Bioenergy report on the status and prospects for using microalgae and macroalgae as feedstocks for biofuels and bioenergy production; the report is available at www.ieabioenergy.com. The scope of the areas covered includes international activities advancing bioenergy and non-energy bio-products from algae, bioenergy from macroalgae (both cast and cultivated seaweeds), distinct biochemical and thermochemical conversion pathways, biorefining opportunities, as well as process economics and sustainability issues.

    Author(s): Melodie Chen-Glasser, James D. McMillan, Lieve M.L. Laurens
  • Algae isn't typically associated with cattle feed, but a Texas AgriLife Research scientist and graduate student have found some interesting results that may change this during their three-phased study.

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  • Cultivation of seaweed in the US faces big barriers: the lack of commercial-scale processing, competition with lower-cost Asian imports, inconsistent oversight, and increasing food safety concerns, say farmers and researchers.

    These problems are preventing farmers from harnessing seaweed’s full potential.

    “Seaweed globally is upwards of a $12-billion industry, just growing and wild harvesting it, whether for cosmetics, filler for food or for human consumption. We are really in a good situation here in North America to provide the best seaweed in terms of nutrient and health value to the rest of the world due to our water-quality regulations. But we are so far behind in terms of growing in the oceans and aquaculture,” says Greg Martino, co-owner of Cottage City Oysters on Martha’s Vineyard.

    Author(s): Liza Mayer , Lynn Fantom
  • Norwegian research scientists from the SINTEF are convinced that kelp may share many of the applications of soy and oil in the fish farming industry. “We can break seaweed down into their basic constituents and recombine them to make useful products,” said researcher Silje Forbord at SINTEF. “We can use seaweed to make clothes, furniture materials, food packaging, drinking straws and biodegradable bottles,” Forbord said.

    The team has been active in the forefront of a research project called MACROSEA, which is providing new insights into the potential of seaweed farming in Norway. The project has also succeeded in developing innovative solutions that will assist in industrializing the Norwegian seaweed sector.

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  • Seaweed aquaculture is a rapidly growing component of marine food production, but the capacity to control seaweed growth lacks behind that of land agriculture. Seaweed growth requires nutrients, acquired from dissolved pools through their fronds, and light, and, as such may also be density-dependent, but general relationships between seaweed growth, nutrient concentration and incident irradiance are not yet available. We used a dataset of 1729 experimental assessments of seaweed specific growth rates and density under various nutrient and irradiance levels retrieved from the published literature to examine the relationship between seaweed growth, density, irradiance, and nutrient concentration. This analysis confirmed strong density-dependence of seaweed specific growth rates, and further confirmed that nutrient and irradiance limitation strongly impose density-dependent seaweed growth. These findings demonstrate that nutrient and irradiance limitation modulate density-dependent seaweed growth, and can help maximize growth rates in seaweed aquaculture, a rapidly growing component of global aquaculture production, by manipulating stocking density where nutrients are scarce and/or underwater light penetration poor.

    Author(s): Xi Xiao, Susana Agusti, Fang Lin, Caicai Xu, Yan Yu, Yaoru Pan, Ke Li, Jiaping Wu, Carlos M. Duarte
  • Industrial effluents such as pharmaceutical residues, pesticides, dyes, and metal processes holds abundant valueadded products (VAPs), where its recovery has become essential. The purpose of such recovery is for sustainable treatment, which is an approach that considers the economic, social, and environmental aspects. Microalgae with its potential in the recovery process from effluents, can reduce energy usage of waste management strategies and regenerate nutrients such as carbon, phosphorus, and nitrogen. Microalgae cultures offer the use of inorganic materials by microalgae for their growth and the help of bacteria to produce biomass, thus, resulting in the absence of secondary emissions due to its ability to eliminate volatile organic compounds. Moreover, recovered bioactive compounds are transformed into bioethanol, bio-fertilizers, biopolymer, health supplements and animal feed. Therefore, it is significant to focus on an economical and efficient utilization of microalgae in recovering nutrients that can be further used in various commercial applications. 

    Author(s): Shazia Ali, Angela Paul Peter, Kit Wayne Chew, Heli Siti Halimatul Munawaroh, Pau Loke Show

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