An overview of seaweed resources in Chile

The seaweed harvest in Chile has doubled during the past decade, and export values have increased by 300% because of diversification and increase in the volume of products with greater value added. The export value of seaweed products increased from US $18 million in 1980 to $52 million in 1991. During the past decade, the successful cultivation of Gracilaria was implemented, and this has compensated for the large decrease in yields from natural beds. In the short term, it will be necessary to develop techniques for the cultivation of other resources such as Iridaea, Gigartina, Lessonia and Gelidium. Alternative biotechnological methods must also be developed, such as the use of Gracilaria strains with increased quality and production for growth in cultivation centers.     

Recent trends of seaweed production in Chile

In the last fourteen years the production of seaweeds in Chile has ranged from 74 000 to 229 000 wet metric tons per year and has included about twenty species belonging to Phaeophyta and Rhodophyta. The only source of this production has been the exploitation of natural beds, except for Gracilaria, which is the only case of commercial cultivation and contributes significant quantities to total production. Initially most of the raw material was exported but currently important quantities of Gracilaria and several carrageenophytes are being processed by local industry. Changes in production of the main resources are analyzed with consideration of potential demand, level of knowledge about natural beds, and the situation of total Gracilaria farming, in order to attempt predictions for the supply. Current possibilities of applying new technologies to cultivate other economically important Chilean seaweeds are also analyzed and discussed.     

Limiting factors in optimizing seaweed yield in Chile

A number of factors influenced yield from natural beds of marine algae in Chile. These factors are related not only to biological and ecological knowledge of the algal resource, but also to external events, such as; (1) the pressure of international markets for raw material, (2) unemployment level of coastal workers, which increases the number of seasonal harvesters, (3) the low level of regulation enforcement along Chile's extensive coast, (4) the low level of education and income of algal harvesters, and (5) except for Gracilaria, the lack of a management plan for algal resources.     

Current state of seaweed resources in Spain

Commercial seaweeds in Spain are harvested on the north and northwest coasts. They are mainly agarophytes and carrageenophytes (Gelidium spp. and some Irish moss-like species, respectively), although some Phaeophyceae species (Fucus spp. and Laminaria spp.) are also exploited for alginates. No industrial seaweed cultivation is carried out in Spain at present. Spain's total commercial seaweed harvest can be estimated at 6,528 ± 2,076 t dry wt year^–1. Gelidium spp. are by far the most harvested, attaining 5,135 ± 1,761 t dry wt y^–1. To date, Spain's commercial seaweed harvest is low compared with that of other countries, but data on field standing crops and productivities of commercial taxa suggest that harvesting could be increased greatly.     

Sustainable harvesting of wild seaweed resources

Abstract

Macroalgae have played an important role in coastal communities for centuries. In the past, they have been harvested and gathered from shorelines around the world for traditional uses such as food, animal feed and a crude fertilizer (marine manure). Today, seaweeds are used in a multitude of applications with expanding global industries based on hydrocolloids, cosmetics and food supplements, and also as a potential biofuel source. However, of the approximately 10?000 algal species reported to exist, only a small number are commercially utilized. While representing only a small fraction of total global seaweed production, harvesting and gathering ‘wild’ seaweeds has had, and continues to have, an integral role in many coastal societies, often being intrinsically linked to the cultural identity of those coastal communities. Today, 32 countries actively harvest seaweeds from wild stocks, with over 800?000 t harvested annually from natural beds. It is vitally important that seaweeds are utilized sustainably and that natural resources are effectively managed by coastal communities with vested interests around the world. As the popularity of seaweeds increases and the use of less traditional species with novel applications comes to the fore, it is critically important to make certain that the sustainability of the resource is ensured given the increased pressures of harvesting. Issues exist regarding ownership of the resource and its over-exploitation, and the implementation of environmentally damaging harvesting techniques must be avoided. Resource scientists, managers, conservationists, governments, and other stakeholders need to be proactive in the sustainable management of these vulnerable, yet valuable, resources.     

World seaweed utilisation: An end-of-century summary

The data for worldwide seaweed production for the years 1994/1995 are summarised. At least 221 species of seaweed were used, with145 species for food and 101 species for phycocolloid production. 2,005,459 t dry weight was produced, with 90% coming from China, France, UK, Korea, Japan and Chile. 1,033,650 t dry weight was cultured with 90% coming from China, Korea and Japan. Just four genera made up 93% of the cultured seaweed: Laminaria (682,581 t dry wt), Porphyra (130,614 t dry wt), Undaria (101,708 t dry wt) and Gracilaria (50,165 t dry wt). The value of the harvest was in excess of US $ 6.2 billion. Since 1984 the production of seaweeds worldwide has grown by 119%. This revised version was published online in June 2006 with corrections to the Cover Date.     

An overview of radioimmunotherapy

Summary In reviewing the current state of affairs in radioimmunotherapy the paper focuses on the main difficulties thus far encountered and the procedures designed to avoid or circumvent these problems. The long range -emitters⁹⁰Y and¹⁸⁸Re have replaced¹³¹I as the isotopes currently receiving most attention for use in radioimmunotherapy, and a range of new chelators are under investigation for in vivo stability and immunogenicity. Approaches aimed at improving tumour targetting and antigen expression such as two-step pretargetting techniques, tumour necrosis treatment and cytokine pretreatment are summarised. Methods designed to improve host-Mab interactions are outlined and the need to incorporate successful ideas from current cancer therapies is emphasised.     

An overview of Acipenseriformes

Acipenseriformes occupy a special place in the history of ideas concerning fish evolution, but in many respects, phylogenetic studies of the group remain in their infancy. Even such basic questions as the monophyly of Acipenser (the largest genus) are unanswered. We define relationships based on comparative osteology, which allows us to incorporate well-preserved fossils into analyses. Acipenseriformes has existed at least since the Lower Jurassic (approximately 200 MYBP), and all fossil and recent taxa are from the Holarctic. Phylogenetic relationships among Paleozoic and Early Mesozoic actinopterygians are problematic, but most workers agree that Acipenseriformes is monophyletic and derived from some component of paleonisciform fishes. (Paleonisciformes is a grade of primitive non-neopterygian actinopterygians, sensu Gardiner 1993.) Taxa discussed in comparison here are: Cheirolepis, Polypterus, Mimia, Moythomasia, Birgeria, Saurichthys, Lepisosteus and Amia. We review generic diversity within the four nominal families of fossil and recent Acipenseriformes (Chondrosteidae, Peipiaosteidae, Polyodontidae, and Acipenseridae), and provide a cladogram summarizing osteological characters for those four groups. Monophyly of the two extant families is well-supported, but there are no comprehensive studies of all of the known species and specimens of Chondrosteidae and Peipiaosteidae. As a result, sister-group relationships among Chondrosteidae, Peipiaosteidae, and Acipenseroidei (= Polyodontidae + Acipenseridae) are unresolved. We discuss five features fundamental to the biology of acipenseriforms that benefit from the availability of our new phylogenetic hypothesis: (1) specializations of jaws and operculum relevant to jaw protrusion, feeding, and ram ventilation; (2) anadromy or potamodromy and demersal spawning; (3) paedomorphosis and evolution of the group; (4) the bioégeography of Asian and North American polyodontids and scaphirhynchines; and (5) the great abundance of electroreceptive organs in the rostral and opercular regions. Finally, we summarize our nomenclatural recommendations.     

An overview of toxicogenomics

Toxicogenomics is a rapidly developing discipline that promises to aid scientists in understanding the molecular and cellular effects of chemicals in biological systems. This field encompasses global assessment of biological effects using technologies such as DNA microarrays or high throughput NMR and protein expression analysis. This review provides an overview of advancing multiple approaches (genomic, proteomic, metabonomic) that may extend our understanding of toxicology and highlights the importance of coupling such approaches with classical toxicity studies.     

An overview of biotechnology in Korea

During the 1980s and 1990s, Korea has invested heavily in biotechnology research and development, with the aim of becoming a leading nation in this field. It is important to understand the historical progress of this development in order to appreciate the current state of biotechology in Korea. However, it is equally important to know what research is currently being planned and carried out, and by whom.     

Immunity in cryptococcosis: An overview

Cryptococcosis is an often fatal opportunistic fungal infection. Despite efforts to elucidate the role of immunity in host defense against the disease, much remains to be learned. The purpose of this brief review is to provide the reader with an overview of the history of research concerned with host immunity in cryptococcosis. Both humoral and cell-mediated studies are included. An effort has been made to present the reader with a comprehensive list of references in the hope of encouraging additional reading and research in this important area.     

An overview of macrophage-fungal interactions

A review of the literature (148 references) on the interactions of fungi with polymorphonuclear cells, monocytes and macrophages is presented. The interactions of Aspergillus species, Coccidioides immitis, Blastomyces dermatitidis, Histoplasma capsulatum, Cryptococcus neoformans, Candida albicans, and Candida species with human and experimental animal derived immune cells are examined in this overview. An effort has been made to present the reader with a comprehensive list of references with the intent of encouraging additional reading and research in this important area.