"This equatorial island of 4,000 people is the latest victim of a 30-year global effort to encourage poor people in the coastal areas of the tropics to grow seaweed that, while not edible, produces carrageenan, an increasingly sought-after binder and fat substitute used in the food industry, notably in ice cream.
Today, about 120,000 dry metric tons a year are produced, mostly in the Philippines and Indonesia, where the two main algae originate.
Kappaphycus alvarezii is most desirable because of its high carrageenan content; Eucheuma denticulatum is less valuable but easier to cultivate.
Both were introduced in the past three decades to 20 countries around the world from Tonga to Zanzibar, and the result in most of them has been failure or worse. The alga K. alvarezii invaded the Gulf of Mannar Biosphere Reserve in south India a decade after commercial cultivation began in nearby Panban. "No part of the coral reef was visible in most of the invaded sites, where it doomed entire colonies," the journal Current Science has reported." (Thanks Rania)