"Extract of seaweed" is often found on the list of ingredients on cosmetic packages, particularly in face, hand and body creams or lotions. This usually refers to the use of alginate or carrageenan in the product, and their uses in cosmetics have already been discussed in earlier sections. More information on the use of these two hydrocolloids, as well as agar, can be found in the reference suggested below for further reading.

The use of seaweeds themselves in cosmetics, rather than extracts of them, is rather limited. Milled seaweed, packed in sachets, is sold as an additive to bath water, sometimes with essential oils added. Bath salts with seaweed meal are also sold. Thalassotherapy has come into fashion in recent years, especially in France. Mineral-rich seawater is used in a range of therapies, including hydrotherapy, massage and a variety of marine mud and algae treatments. One of the treatments is to cover a persons body with a paste of fine particles of seaweed, sometimes wrap them in cling wrap, and warm the body with infrared lamps. It is said to be useful in various ways, including relief of rheumatic pain or the removal of cellulite. Paste mixtures are also used in massage creams, with promises to rapidly restore elasticity and suppleness to the skin. The seaweed pastes are made by freeze grinding or crushing. The seaweed is washed, cleaned and then frozen in slabs. The slabs are either pressed against a grinding wheel or crushed, sometimes with additional freezing with liquid nitrogen that makes the frozen material more brittle and easier to grind or crush. The result is a fine green paste of seaweed.

There appears to be no shortage of products with ingredients and claims linked to seaweeds: creams, face masks, shampoos, body gels, bath salts, and even a do-it-yourself body wrap kit. The user must judge the efficacy of these products. One company recently pointed out that the lifetime of cosmetic products has reduced over the years and now rarely exceeds three or four years. Perhaps the seaweed products that are really effective will live longer than this.

Ground or powdered seaweed, as well as phycocolloids, are used in the manufacture of cosmetic products including soaps, shampoos, powders, creams and sprays. Very often the algal content of such products will be small, even where the use of seaweed is highlighted in the marketing of a product.

A variety of seaweeds are used in cosmetics. Among the brown algae Laminaria spp are among the most common, although the bladder wracks such as Fucus vesiculosus and Ascophyllum nodosum are also utilised. Chondrus crispus, Mastocarpus stellatus and Porphyra spp are some of the red algae, which may be employed as cosmetic ingredients. Overall, though, the quantities of seaweed used in this sector are minimal.

In Europe, France has by far the most extensive use of seaweed in cosmetic products, with around 5,000 t (wet) processed in a variety of ways before sale to the cosmetic sector. In the UK several manufacturers of cosmetic products use small quantities of seaweed.

Wholesalers/suppliers in this sector are thought to pay ca £1/kg for seaweed meal made from fucoids. Laminarians can be more valuable, as can seaweed, which is further processed beyond a basic meal. Generally UK suppliers only stock small quantities of seaweed. It is possible to sell direct to some manufacturers of cosmetic products.

The use of seaweed in cosmetic products is liable to increase, as is the interest in health and fitness to the benefit of areas like thalassotherapy, which utilises seaweed.

Nevertheless, for the purposes of this study the cosmetics market should be viewed as high value but very low volume. The prospects of selling to the leading European market (France) are slim in the face of plentiful local supplies of seaweed in raw or processed form. French suppliers of processed weed would also represent established competition within the cosmetics sector in the UK and other European countries.

Sales of seaweed to the cosmetics sector could be a profitable and worthwhile exercise for an existing seaweed business in the Western Isles, but would not in itself generate sufficient revenue upon which to base a business.

Algotherapy - therapeutic use of seaweed in spa treatments.
Humans have found uses for seaweed for more than a thousand years. In parts of Europe, the oldest written records indicate that dulse (Palmaria palmata) has been collected from rocky shores since at least 600AD. Nori (Porphyra sp.) has been a cultivated cash crop for about 300 years in the East. Nori is an essential component of soups and increasingly popular sushi rolls. In Scotland and Ireland, dulse is eaten dried like potato crisps but is also added to many basic dishes. Perhaps the most important product extracted from seaweeds, however, are the hydrocolloids - gelling polysaccharides (chains of simples sugars) that can be likened to gelatine obtained from animals.

Food, cosmetic and pharmaceutical industries use three common types of hydrocolloid extensively when thickening or gelling properties are required: carrageenan and agar from red seaweeds and alginic acid from brown seaweeds. Green seaweeds do not contain any hydrocolloids, which are used industrially, though they have other uses.

New and more advanced uses are being developed for these gels and for other seaweed products. Until now, there has been no centralised source or efficient method of keeping up to date with developments in the seaweed industry. Seaweed Africa is a European Union-funded project to expand AlgaeBase, a global biodiversity database of seaweed information, to include ecological, commercial and technology data from the whole of Africa. SeaweedAfrica brings together the expertise of scientists from Ireland, Sweden, France, Portugal, Kenya, Tanzania, Moçambique, South Africa, Namibia and Brazil. One of the important aims of the collaboration is to establish a database that includes detailed information of the world-wide use (current or potential) of macroalgae.

Following a detailed literature and Internet survey, many current and potential uses of seaweeds have been identified and catalogued. For ease of access, these have been organised into the following categories: i) aesthetics, ii) agriculture, horticulture and agronomy, iii) uses in animal aquaculture, iv) cosmetics, v) environmental health, monitoring and remediation, vi) food, vii) health, thalassotherapy and wellness, viii) industry, ix) pharmaceutical and pharmacology, x) science, technology & biomedicine, xi) miscellaneous uses. The number of uses in each of these categories is shown in the table below.

It is evident that most people unknowingly utilise seaweed products daily in the form of many convenience foods (processed dairy, meat and fruit products) and domestic commodities (paint, toothpaste, solid air fresheners, cosmetics, etc.). But the cryptic nature of seaweed utilisation contributes to this valuable and renewable resource being generally unappreciated and undervalued by the public.

While the many uses of seaweeds are currently published, many of the records are in specialised journals; the SeaweedAfrica database collates them for the first time. The incredible number of uses that have been documented has surprised even the specialists involved and serves to underline the importance of seaweeds in the world today and the need for concentrated efforts to promote research into the potential uses of these weeds. Of particular interest are the many pharmaceutical applications, in particular due to biologically active secondary metabolites, and the scientific/biomedical sectors incorporating novel uses and applications of hydrocolloids.

Among the more important potentially useful algae are Aghardhiella subulata (cited as A. tenera) which may be useful in the treatment of the human immunodeficiency virus or HIV, and the edible wakame (Undaria pinnatifida) which some researchers speculate may prevent breast cancer. The fact that the SeaweedAfrica database is directly linked to the main AlgaeBase database will mean that all data will be referenced to current taxonomic and nomenclatural data (the need for this can be clearly seen in the above example of Agardhiella).

Studies on the diversity, physiology, biochemistry and utilisation of potentially useful species will be necessary to harness the full potential of seaweed resources and to do so sustainably. This is particularly true in Africa, which can successfully use examples from South East Asia that has a long history of seaweed utilisation. It is envisioned that an industry based on seaweeds has the potential to contribute to sustainable employment opportunities and socio-economic upliftment in emerging economies. African coasts have a generally high biodiversity of seaweeds where opportunities for specialisation of utilisation and development of niche products based on seaweed raw materials from pollution-free environments may be key marketing advantages.

Seaweed Africa will contribute by gathering relevant information in both European and African contexts and constructing a user-friendly online database for practitioners and decision-makers. Accessibility to the information will be ensured via general availability on the Internet and distribution of CD-ROMs and information packs (free of charge) where appropriate. The database is currently in a development stage and is not yet available to the general public. Intensive testing begins in November and soon after the database will be available to the general public and other interested parties.