Some Seaweed Aquaculture History

• Click here for a brief history for seaweed uses in Ireland

Intensive seaweed cultivation in China began in 1951 with the farming of an introduced kelp from Japan, Laminaria japonica (ribbon weed). In 1952 some 62 tons of fresh kelp were produced, whereas in 1998 the harvest reached an incredible 3 million tons, dry weight. Large-scale seaweed mariculture is carried out only in Asia. Most cultivated seaweeds are grown as human food, although, notably in the Philippines, Taiwan and some African countries seaweed is cultivated to be used for carrageen and crude agar production. Cultivated species of global importance used in the food industry are Nori and different types of kelp ( Laminaria japonica and Undaria pinnatifida)

The major producer of seaweeds is China, followed by other Asian countries. The majority of seaweed produced by aquaculture is used for human consumption and for extraction of hydrocolloids (Alginates, Agars and Carrageen). In European countries seaweed aquaculture is a relatively novel development and still in its infancy, with only a small number of commercial seaweed farms. Research is focused on the establishment of low-volume high-value seaweeds in aquaculture. Moreover, new applications of algae and specific algal compounds in different sectors, such as food supplements, cosmetics, biomedicine and biotechnology are developed. Recent trends in life style towards natural, healthy products are favourable for advancement of seaweed aquaculture in Ireland  

(Brief history of seaweed use in Ireland)

For over 2000 years, a red seaweed called Nori ( Porphyra, a flat blade-like red seaweed also called Purple Sea-vegetable or Laver) was used as a subsidiary food  in Asia, and other algae were used as food and medical purposes. Natural resources were adequate and initially there was no need for cultivation. Due to the increasing demand and short supply of Nori , the first steps were taken to start to cultivate this species in a simple way in 17 ^th century Japan by placing brushwood in the mud of Edo (Tokyo) Bay. With ever-increasing demand after World War II new cultivation techniques developed to make Nori cultivation the largest marine aquaculture industry in Japan. Today 350,000 tonnes of wet Nori are cultured each year in Japan, with a retail value well over US$ 1 billion.

A very popular sea-vegetable used in Asian cooking is the kelp Undaria pinnatifida or Wakame with a harvest of over 450,000 and 500,000 tons in Japan and Korea, respectively.  In Ireland we have a native Irish equivalent of Wakame, i.e. Alaria esculenta literally edible wings.  Atlantic Wakame, as it is becoming known, has considerable potential as a foodstuff for human consumption for the home and export market or as a sustainable, cheap and alternative source for protein, vitamins/minerals and biostimulants in animal feed for agriculture and aquaculture.

Worldwide seaweed aquaculture is a growing sector. Latest figures show a production of over 10 million tonnes wet weight with an economic value of 5.6 billion US$. The most suitable seaweed species for cultivation in Ireland for the near future are those, which are already used in trials and /or commercial cultivation operations in Ireland and other western countries. For these specific species a real market demand exists. These include algae for human consumption, nutraceuticals and cosmetics. One species successfully cultivated in Ireland for use in cosmetics is the red seaweed Asparagopsis armata. Several bioactive molecules are extracted from this species, which are used in acne and anti-dandruff products or as natural preservative for cosmetics.