The corals of atolls in island of Kiribati republic are facing danger from something beyond global warming. In Butaritari, a well-known island of Gilberts chain of Kiribati and land area of 13.6 km², the coral reefs are now becoming a victim of algae Eucheuma, introduced by humans for commercial aspects. In Hawaiian Islands, 3 kinds of algae are farmed currently, one of them being Eucheuma which has already destroyed the coral heads of Kaneohe Bay. These algae were brought here during early 70’s by Max Doty, a professor of botany at the University of Hawaii. He developed the techniques of algae cultivation which are now followed by farmers in Kiribati, the Solomon Islands and Tonga.

The algae s harvested for commercial purposes. Eucheuma is seaweed which is cultivated by poor local people of the above mentioned islands. It is not edible seaweed but is grown in huge number to extract carrageenan (a sought-after binder & fat substitute in food industry, used as an emulsifier in ice creams!).

Eucheuma has a low content of carrageenan; hence, needs to be cultivated in large quantities.
The issue now at face is that this sea weed has infected the coral reef of Butaritari. The bushy seaweed nestles itself in the reef’s crevices thus driving out the tropical fishes that once housed these coral reefs. Moreover, this seaweed is so tough that it is avoided by algae-grazing fish also. Besides disturbing the reef’s ecology, the large numbers of weed (Eucheuma) are also fouling the nets of local fishermen. These poor people are not able to catch enough fishes for their survival. Thus the seaweed is indirectly hitting the topmost occupant of the food chain as well! The sad story doesn’t end here. These seaweeds grow at a rate of 7 percent a week; meaning, if this goes on like this for a few more years, the entire coral reef of Butaritari would be destroyed by it!

According to Dr. Jennifer E. Smith of the National Center for Ecological Analysis and Synthesis at the University of California, Santa Barbara, Eucheuma is one of the most damaging seaweeds known today. She has studied the Hawaiian invasion for eight years.
Alarmed by the seaweed population, she said, “If there is that much Eucheuma in Butaritari, it proves it can destroy a healthy reef as opposed to a degraded one like in Kaneohe.” Addressing her concern on the increasing coral mortality rates Dr. Smith also said, “Introduced species have had large impacts on marine ecosystems around the world”.

The local fishermen, ecologists and government are still trying to figure out some concrete solution to relieve the stress faced by the corals by this seaweed. What is required is a synergistic move by all the three bodies. But so far the scenario is disheartening only. The world community should take a lesson or two from what is happening in Butaritari that, intentional introduction of species in any ecosystem can cause more harm than imagined by people.

Via NYTimes