WWW.WAS.ORG • WORLD AQUACULTURE • JUNE 2014 33 (GRAPHICS CONTINUED ON PAGE 32, TEXT CONTINUED ON PAGE 34) Atlantic rockweed Ascophyllum nodosum and Skottersberg’s gigartina Gigartina skottsbergii, each accounting for 2 percent of total production (Fig. 4). In cases where data is only available on a frozen weight basis, for instance Japanese kelp, other red seaweeds and other green seaweeds, 80 percent moisture was used as a basis for the conversion to dry weight for comparison. Cultivated Seaweed Production Cultivated seaweeds account for the largest quantity of total global seaweed production. Several techniques are used to cultivate seaweeds, ranging from monoculture, where spores are ‘seeded’ on ropes or nets, floating or fixed on stakes on seabeds or rafts in coastal waters, to onshore cultivation systems, such as earthen ponds, tanks and raceways (Fig. 5). The open water, longline system is very common in countries such as China and the Philippines. Integrated Multi-Trophic Aquaculture (IMTA) is gaining popularity, where several species at different trophic levels are cultivated in a single system at different biomass proportions, with each component utilizing the waste products or biomass produced by the other component in the system. Each component must be marketable for the system to be viable (Chopin et al. 2008). Seaweeds are a very popular choice in these systems as a primary producer utilizing the nutrient wastes of fish and bivalves. Global aquaculture production of aquatic plants in 2010 was 19 million t with an estimated farm gate value of US$5.7 billion. Seaweeds dominate the production of aquatic plants, accounting for over 99.5 percent in quantity and 99.1 percent in value in 2010 (Figs. 1 and 6). Production from aquaculture was over 95.5 percent of the total global seaweed production. The culture of aquatic plants has grown at 7.7 percent/yr since the 1970s (FAO 2010). Countries in East and Southeast Asia dominate global seaweed production from aquaculture, accounting for 99.6 percent by quantity and value in 2010 (Fig. 7). China, the largest seaweed producer, accounted for nearly 58 percent of global cultivated seaweed production by quantity and 45 percent by value. Other major seaweed producers include Indonesia, Philippines, South Korea, Japan and North Korea. In terms of value, however, Japan maintained its position as the third major seaweed producer because of its high-value nori production, accounting for 20 percent of global production (FAO 2010, 2011). The impact of the 2011 tsunami is very likely to have had a major impact on Japan’s seaweed production, although there is not yet confirmation in official statistics. In East Asia, almost all cultured seaweed species are used for human consumption. A small proportion of Japanese kelp is also used as a raw material for the extraction of iodine and algin. In Southeast Asia though, Eucheuma seaweeds are the dominant cultivated species, used mainly as a raw material for carrageenan extraction. Outside Asia, Zanzibar (Tanzania) and Chile are important seaweed cultivating countries, producing about 0.13 and 0.01 t in 2010, respectively. In terms of market value, these were not substantial (Fig. 7). South Africa and Madagascar are other leading producers outside Asia. Cultivated seaweed production in Tanzania and Madagascar are mostly Eucheuma seaweeds for export. In South Africa, cultured seaweeds are harvested mainly as feed to support abalone aquaculture (FAO 2010, 2011). The dominant cultivated brown seaweed species include Japanese kelp Laminaria japonica, wakame Undaria pinnatifida and fusiform sargassum Sargassum fusiforme. The red seaweeds included Eucheuma seaweeds, elkhorn sea moss Kappaphycus alvarezii, Warty gracilaria Gracilaria verrucosa, nori Porphyra spp., other gracilaria seaweeds, laver or nori Porphyra tenera, spiny eucheuma Eucheuma denticulatum and Japanese isinglass Gelidium amansii. The green seaweeds included bright green nori Enteromorpha clathrata, green laver Monostroma nitidum, caulerpa seaweeds Caulerpa spp. and fragile codium Codium fragile (FAO 2012). The most-produced cultivated seaweed in 2010 was Japanese kelp (Fig. 8), accounting for over 33 percent of the global cultivated seaweed production (5.1 million t), followed by Eucheuma seaweeds at 22 percent (3.5 million t), elkhorn sea moss at 12 percent (1.9 million t), wakame at 10 percent (1.5 million t), warty Gracilaria and other nori at 7 percent (1.2 million t). In the 1990s Japanese kelp accounted for the bulk of cultivated seaweed production. Collectively, Kappaphycus and Eucheuma accounted for less than 10 percent of the total cultivated Japanese kelp production. As a direct consequence of skyrocketing global demand for the hydrocolloid carrageenan in 2000, countries such as China, Indonesia and the Philippines focused largely on cultivation of the carragenophytes (Kappaphycus and Eucheuma). By 2005, the carragenophyte production was nearly half that of Japanese kelp, superseding production in 2010. This increase in production is most obvious in the farming of Eucheuma seaweeds. In terms of value, Eucheuma seaweeds accounted for 27 percent (US$1,135 million) of the global cultivated seaweed market, followed by nori accounting for 26 percent (US$1,095 million), wakame 16 percent (US$667 million), warty Gracilaria at 8 percent (US$342 million), Japanese kelp at 7 percent (US$301 million), Elkhorn seamoss at 6 percent (US$203) and Gracilaria seaweeds (US$198 million) at 4 percent (Fig. 9, FAO 2012). TABLE 2. Growth of seaweed imports in the major markets of the world 1999-2008 (Infofish International 2011). COUNTRY GROWTH (%) Japan +10 Taiwan +13 Brazil +59 USA +65 Canada +87 France +93 Thailand +182 Mexico +183 Australia +189 Russia +345 China +673 Philippines +2800
RkJQdWJsaXNoZXIy MjExNDY=