Seaweeds derived by-products

In terms of volume, farmed seaweeds in 2018 made up 97.1% of the combined 32.4 million tonnes of wild-collected and cultivated aquatic algae. A comparatively small number of nations, mostly those in East and Southeast Asia, practice seaweed farming. Between 2000 and 2018, the global output of marine macroalgae, sometimes known as seaweed, increased by more than thrice, from 10.6 million tonnes to 32.4 million tonnes. The trade of seaweeds in 2018 was of USD 2 billion. Seaweeds dominate aquacultured aquatic algae, which have shown very slow growth in recent years. Some of the 32.4 million tonnes of farmed seaweed produced in 2018 (such as Undaria pinnatifida, Porphyra spp., and Caulerpa spp., produced in East and Southeast Asia) are produced primarily for human consumption, though low-quality products and factory scraps are used for other things, such as abalone culture feed. In fact, seaweed production decreased by 0.7% in 2018. This shift was mostly brought on by Southeast Asia's decreased production and the slow growth of tropical seaweed species, while the production of temperate and coldwater species from seaweed farming was still increasing. The major factor behind the rise in farmed seaweed production over the past 10 years, despite a recent slowdown in growth rates, has been the rapid expansion of the farming of tropical seaweed species in Indonesia (Kappaphycus alvarezii and Eucheuma spp.) as a source of raw materials for the extraction of carrageenan. From less than four million tonnes in 2010 to over 11 million tonnes in 2015 and 2016, with comparable production levels in 2017 and 2018, Indonesia boosted its seaweed farming output. Due to secrecy, only a few producing nations in Europe and North America have reported much information on small-scale seaweed growing. To promote and monitor the development of a bioeconomy that is climate and environmentally sustainable, seaweed farming is nevertheless receiving more and more attention.