Wednesday, July 9, 2008

Choking algae

We never learn. Driven by our desire to accumulate even more wealth, we always try to come up with "creative" solutions, usually by taking one species from an environment and introducing it to another one where the physical environmental conditions allow cultivation. These species fare well because they have few if any predators, and then they get out of hand and they destroy the local ecosystems.

"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)

1 comment:

Leila Abu-Saba said...

California is still infested with Australian eucalyptus trees introduced over a hundred years ago in a get-rich-quick scheme gone wrong. The planter thought this sort of eucalyptus was the hardwood that would make fine lumber - he was wrong. The trees are utterly useless. They are also invasive, hard to kill, and they put off a poison that eradicates all plant life around them. They are furthermore quite flammable and tend to explode in a brush fire, making the flames carry long distances. And if they get very old and large, they tend to fall over and kill people.

Some things haven't changed. The algae story is indeed a tragedy...