Digital library

  • Up-to-date information about the unique marine flora of the Hawaiian Islands – its environment, uses, cultivation, conservation, and threats – comes from many sources, and is compiled here for the first time. The seaweed resources of the Hawaiian Islands are taxonomically diverse, biogeographically intriguing, ecologically complex, culturally significant, and economically valuable. Macroalgae, historically and today, are critical components of the marine ecosystem, as well as the diet and culture of people living in the islands. Some Hawaiian seaweeds are known to contain valuable bioactive compounds that have potential medical and pharmaceutical applications. Cultivation of Hawaiian seaweeds is carried out in tanks, ponds, and along the shoreline, both commercially and by “back-yard” farmers. Several community groups are actively working to preserve cultural knowledge, to re-plant the reefs, and to remove invasive algal species. The seaweed resources of Hawaiʻi are cherished, but are at risk. The future of seaweed cultivation, maintenance and revitalization of native populations, and preservation of cultural knowledge relies on the collaborative efforts of all stakeholders.

    Author(s): Karla McDermid, Keelee Martin, Maria C. Haws
  • The deepwater seaweed resources survey was carried out during 1986-1991 at the depths ranging from 5 to 22 m in Tamilnadu coast from Dhanushkodi to Kanyakumari. The vegetation of seaweeds and sea grasses occurred in all areas except Dhanushkodi - Mandapam and Manapad – Kanyakumari. A total number of 100 algae and 5 seagrasses were recorded. Among the 100 algal species recorded, 20 species belonged to Chlorophyta, 18 species to Phaeophyta, 61 species to Rhodophyta and 1 species to Cyanophyta. The total estimated standing crop (wet wt.) from 1863 sq. km. sampled area was 75374.5 tonnes consisting of 2750 tonnes of Sargassum spp., 962.5 tonnes of Gracilaria spp., 5262.5 tonnes of Hypnea spp. and 66399.5 tonnes of other seaweeds. The quantitative analysis of economically important seaweeds revealed the feasibility of commercial exploitation of Sargassum from Mandapam to Kilakkarai and Tuticorin areas, Hyphnea from Mandapam to Vembar area and Gracilaria from Vembar to Nallatanni Tivu region. Hydrological data were, also collected from the area surveyed.

    Author(s): Kaliaperumal, N, Chennubhotla, V S Krishnamurthy, Kalimuthu, S, Ramalingam, J R, Pillai, S Krishna, Muniyandi, K, Rao, K Rama, Rao, P V Subba, Thomas, P C, Zaidi, S H, Subbaramaiah, K
  • This manual is designed for farmers, buying agents, exporters and fisheries officers who play an important role in achieving the required quality of seaweed for export. The purpose of the manual is to educate farmers to understand the importance of good-quality seaweed, the role they play and the benefits they can achieve. The manual also provides guidance for buying agents, exporters and fisheries officers in the roles they perform to improve and maintain the required quality of seaweed.

    Author(s): Gideon Tiroba
  • The use of seaweeds has a long history, as does the cultivation of a select and relatively small group of species. This review presents several aspects of seaweed production, such as an update on the volumes of seaweeds produced globally by both extraction from natural beds and cultivation. We discuss uses, production trends and economic analysis. We also focus on what is viewed as the huge potential for growing industrial-scale volumes of seaweeds to provide sufficient, sustainable biomass to be processed into a multitude of products to benefit humankind. The biorefinery approach is proposed as a sustainable strategy to achieve this goal. There are many different technologies available to produce seaweed, but optimization and more efficient developments are still required. We conclude that there are some fundamental and very significant hurdles yet to overcome in order to achieve the potential contributions that seaweed cultivation may provide the world. There are critical aspects, such as improving the value of seaweed biomass, along with a proper consideration of the ecosystem services that seaweed farming can provide, e.g. a reduction in coastal nutrient loads. Additional considerations are environmental risks associated with climate change, pathogens, epibionts and grazers, as well as the preservation of the genetic diversity of cultivated seaweeds. Importantly, we provide an outline for future needs in the anticipation that phycologists around the world will rise to the challenge, such that the potential to be derived from seaweed biomass becomes a reality.

    Author(s): Alejandro H. Buschmann, Carolina Camus, Javier Infante, Amir Neori, Álvaro Israel, María C. Hernández-González, Sandra V. Pereda, Juan Luis Gomez-Pinchetti, Alexander Golberg, Niva Tadmor-Shalev, Alan T. Critchley
  • Seaweed is known as an abundant source of minerals. Mineral composition of seaweed is very changeable because of many exogenous and endogenous factors and differs also within the same species. Principally, seaweed is an excellent source of some essential elements. Mainly, iron and iodine are in high concentration. Seaweeds could be prospective as functional foods and also producers of mineral nutraceuticals.

    Author(s): Ladislava Misurcova, Ludmila Machu, Jana Orsavova
  • Seaweed mariculture has been promoted as a development project in tropical countries and Zanzibar, Tanzania, is commonly presented as a successful story. However, the results of the present research provide a nuanced picture of the activity identifying serious health problems among farmers. Semi-structured interviews were conducted with female seaweed farmers (n = 140) and non-seaweed farmers (n = 140) in Zanzibar to evaluate health and working conditions. In-depth interviews with additional 28 female seaweed farmers were performed to deepen the understanding of the working conditions and related problems. The research was undertaken at seven different locations to cover areas where seaweed is extensively executed during August to September 2009 and May to June 2010. Seaweed farmers considered their health significantly poorer than non-seaweed farmers with fatigue, musculoskeletal pain, hunger, respiratory problems, eye related problems, injuries from hazardous animals and sharp shells in the water and allergies as the most serious issues (p b 0.05). Income was further reported below the extreme poverty line. Since seaweed farming affects thousands of households in the tropics these results should encourage changes towards better working conditions and sustainability.

    Author(s): Sara Fröcklin, Maricela de la Torre-Castro, Lars Lindström, Narriman S. Jiddawi, Flower E. Msuya
  • In the past, storm cast* seaweed was gathered on foot and without mechanization or any equipment. Since the beginning of the 17th century, the commercial use of seaweed, for commercial purposes, such as in the production of glass, encouraged local populations to regulate the activity by establishing rules. For example in France, the first national text, regulating seaweed harvesting, is an ordinance of 1681 which fixed the harvesting seasons of kelp and the number of authorized harvesting days. The use of seaweed for iodine production and later for alginate prompted improvements in harvesting techniques, in order to meet the increasing industrial demand industry for the raw material. Equipment to cut seaweed and boats to carry the algae ashore were first used early in the twentieth century. In 1970, harvesting of Laminaria digitata and Laminaria hyperborea was mechanized in France and Norway. In Europe, the main exploited algae species are Laminaria hyperborea, Laminaria digitata and Ascophyllum nodosum. These species, and especially kelp forests, are considered among the most ecologically dynamic and biologically diverse habitats on the planet. Other species are found on the European Atlantic coast but few of them currently have a commercial value. European scientists have mainly focused their research mainly on kelp which is considered a Keystone Species and whose presence affects the survival and abundance of many other species in the ecosystem. Nowadays, the preservation of kelp forests is placed at the center of environmental concerns and some countries have decided to protect these habitats by restricting the use of mechanical harvesting or by creating protected areas around them. Within this context, mechanical kelp harvesting and seaweed gathering by foot, generate much discussion between scientists, fishers, processing industries and environmental non-gouvernemental organisations. Kelp harvesting is blamed for harming the ecosystem because of the damage it can cause to substrates and to the habitats of certain fish. For some scientists the removal of the kelp species provokes negative effects on the invertebrate species that live in the holdfast, the stipe or fronds or under the fronds. In countries where Laminaria spp is harvested with mechanical equipment, scientists appear to be concerned with the equipment’s impact on the species and also on the surrounding ecosystem. This document presents the main characteristics of the seaweed industry in Europe, illustrated by examples from six European countries (Norway, France, Ireland, Spain, United Kingdom and Portugal). The aim is to have an overview of the European seaweed industry from the six baseline reports prepared by the partners of this project, from literature sources and information gathered during semi-structured interviews of different stakeholders. This document briefly presents the history of seaweed harvesting activity in Europe, the current production and the techniques used in the different countries. The different regulatory systems for the resource and coastal access are detailed followed by the management of the resource and finally the management of the human beings focusing on the social dimension of the activity. The diverse uses of the seaweed resource are outlined.

     

    *material deposited on the shore after storms

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  • Ocean acidification is just one of the ways in which coastal communities are already feeling the effects of a changing global ocean. The potentially devastating ramifications have made it an urgent environmental and economic issue. A collaborative project led by the Puget Sound Restoration Fund in conjunction with NOAA and other partners, was just awarded $1.5 million by the Paul G. Allen Family Foundation to tackle the impacts of ocean acidification. The project looks to employ an unlikely hero: seaweed.

    “There are not a lot of tools in the tool box that can fight ocean acidification or remove carbon dioxide (CO ) from the ocean” says Dr. Michael Rust, NOAA Aquaculture Science Coordinator and a collaborator on the project. “Seaweed farms might be one of our best bets.”

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  • Development of alternative livelihoods has become a popular policy to uplift the socio-economic status of small-scale fishers and to reduce fishing pressure on overexploitedfisheries. Seaweed farming has been incorporated into many community-based coastalresources management projects and fisheries management initiatives as an alternativelivelihood option for fishers in tropical developing countries. This is typically based onseveral assumptions, either unstated or explicit, of program designers, project managersand senior policy makers. First, it is often assumed that small-scale fishers are poor andthat this is related in many cases to the overexploited nature of the resource. Secondly, itis assumed that fishers are willing to give up fishing in favor of more lucrative economicopportunities, such as seaweed farming. Lastly, it is assumed that as fishers take upalternative livelihoods such as seaweed farming, this will reduce pressure on the fisheries.This is an excellent example of a project logic framework whereby certain inputs (e.g.promotion of seaweed farming) will lead to specific outputs (e.g. improved socio-economic status of fishers, reduced fishing pressure and improved resource status). Thispaper will examine the evidence underlying these assumptions and the extent to whichdevelopment of seaweed farming as an alternative livelihood can increase socio-economic status of fishers and reduce fishing pressure based on a number of examplesfrom coastal communities in North Sulawesi, Indonesia

    Author(s): Brian Crawford
  • In Chwaka Bay, aquaculture (the farming of aquatic organisms) is represented by a small-scale but much debated activity; farming of marine macroalgae, or seaweed farming. Aquaculture as a whole dates back several millennia in areas like South-East Asia, but has during the last decades become heavily promoted as an alternative livelihood in developing countries to (i) reduce pressure on overharvested natural resources (e.g. fish stocks) and (ii) supply cheap food and income (Tacon 2001). Many promises of this “Blue Revolution” have, however, not been fulfilled, because technical know-how and experience is often lacking (Dadzie 1992; Machena and Moehl 2001), and because some of the hitherto dominating forms (for example farming of giant shrimp/prawns) have been riddled with huge sustainability problems of their own (Deb 1998; Bryceson 2002).

    Seaweed farming is, in comparison to e.g. intensive shrimp farming, an alternative form of aquaculture, which has been described as “the most sustainable” form of aquaculture. This is primarily because (i) farming can be conducted in shallow coastal areas or the open ocean (instead of in dugout ponds), (ii) the seaweeds require no addition of fertilizers or pesticides, only enough light and water mo- tion, (iii) the rapid growth rate (up to 15 percent per day) results in relatively short farming cycles (Mshigeni 1976; FAO 2002), and (iv) farming generates a cash income to farmers. Most open-water seaweed farming involves two genera of tropical red algae (Rhodophyta); Eucheuma and Kappaphycus (Zemke-White and Ohno 1999), farmed for the extraction of carrageenan; a valuable polysaccharide used as a stabilizing, emulsifying and thickening agent in food, cosmetics and pharmaceuticals.

    Author(s): Johan S. Eklöf, Flower E. Msuya, Thomas J. Lyimo, Amelia S. Buriyo

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