Journal of the Marine Biological Association of India

Volume 31 Issue 1&2

Exploitation and management of seaweed resources in Northeast Brazil.

Muttutamby Durairatnam

The north eastern coast of Brazil favours the growth of many algae including those producing agar, agarose, carragheens, alginates and mannitol. More than 300 species growing on corals, reefs, rocks and sand stones are widely distributed along this coast. The seaweeds of economic importance found in Northeast Brazil are listed in this paper. The export of raw materials in tropical countries consists of two principal types. One of the colloids produced is agar and the other carragheen. Species of Hypnea and Solieria produce caragheen and the raw material is exported to America and Europe. Species of Gracilaria produce agar. About twenty species of Gracilaria are found in Northeast Brazil. The raw material is mainly exported to Japan. Both agar and carragheen are produced by two companies, Brazil Agar from the State of Paraiba and C. Algas from the State of Sao Paulo. At present each company produces four tonnes of agar per month due to a shortage of raw materials. The raw material of Gracilaria and Hypnea are exported to Japan and America. It is estimated that about 1500 tonnes of raw material can be harvested annually. During the last ten years there has been a depletion of stock due to over exploitation. To prevent over exploitation and proper management of the resources the following steps should be taken to develop the seaweed industry.

Legislation should be passed that during the peak reproduction period harvesting should be on a reduced basis or completely avoided, 2. Raking of seaweeds over loose substrata or where seaweeds are attached to stones or pebbles should be avoided. 3. For proper management of the seaweed resources the gear used for harvesting must not scrape the substratum. 4. Ecological studies should be undertaken in the field and in the laboratory to determine the best period of harvesting. 5. Efforts should be made to prevent pollution in the areas of harvesting. 6. Carry out culture experiments on algae similar to that carried out in Taiwan. 7. Encouragement of community organisation of a seaweed production is needed.

Date : 31-12-1989