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Seaweed and monsoon rains:
The SeaweedAfrica workshop in Zanzibar

One of the (few?) benefits of being a biologist is that your work sometimes takes you to exotic places. The SeaweedAfrica project, which started four years ago and ended officially in October 2005, set some sort of record, with workshops in Ireland, Namibia, Kenya, Portugal, Zanzibar and Cape Town. The EU funders (Inco-Dev section of the Fifth Framework Programme) insisted that all participants attend the workshops, in order to establish good links between the various (and particularly southern African) participants. The penultimate workshop was held in Zanzibar, Tanzania, in April 2005, and proved one of the most exotic and phycologically interesting.

SeaweedAfrica is a website that provides online information on all aspects of seaweed uses and biology that may be relevant to Africa and Africans. It went online near the end of 2004, and can be found at www.SeaweedAfrica.org. The project is essentially an extension of Prof. Mike Guiry’s AlgaeBase, which is the definitive website on the taxonomy and nomenclature of worldwide seaweeds, and is co-ordinated by the AlgaeBase project team at the Martin Ryan Institute, National University of Ireland, Galway. The software side of SeaweedAfrica was handled by programmers in Galway and at the International Ocean Institute (University of the Western Cape, South Africa), while they and all the other partners designed the structure of the website, worked out what information should go onto it, and gathered and entered the information.

The traditional dhow with a view of Stone Town in the background.

I traveled to Zanzibar with my colleagues Mark Rothman (MCM) and John Bolton (UCT), and we started our trip with two days of informal “phycologising” at Kendwa Rocks, a small backpacker-type of resort on the north coast of Zanzibar. After checking into our cheap but comfortable bungalow, and dealing with a large and surprisingly fast, yellow scorpion that was inside John’s mosquito net, we headed for the beach. Despite the impending monsoon rains, we were able to enjoy good weather while we explored the tidal flats off Kendwa, armed only with Jaasund’s “Intertidal Seaweeds in Tanzania” and spine-proof footwear. There is something truly marvelous about life on tropical shores, and I became very nostalgic when the creatures we found brought back memories of two field trips to Inhaca Island, as an undergraduate at Wits in the early 1970’s. The evenings were spent applying mosquito repellant and sipping Safari beer in the beach boma. There, surrounded by European youths in flimsy beach-wear, John commented sadly “I feel like the Headmaster here ...”. At least we did not look as out-of-place and uncomfortable as the Japanese girl who, for fear of mosquitoes, never removed her full-length clothing, boots, and gloves: all this in tropical heat and humidity!

The workshop was held in the ‘Zanzibar Beach Resort Hotel” some distance from Stone Town, the social and commercial centre of the island. About 17 participants represented the partner countries of Ireland, South Africa, Portugal, Sweden, Mozambique, Namibia, Kenya, Mozambique and Tanzania. The project had reached an important stage, where the last software problems were being solved and information had to be prioritized for entry, so there was much lively discussion in the several days that followed. During this time we were taken to visit the seaweed-farming operations at Paje, on the east coast of Zanzibar. There we saw kilometres of large, neat rectangles of the carrageenan- producing red seaweeds Eucheuma and Kappaphycus planted out over the tidal flats, and watched while local women tied plants onto nylon lines (the tie-tie” method) and strung them between stakes in the sand.

We also visited the Tanzanian Institute of Marine Research, where staff presented a series of talks on marine research in Tanzania, and this was followed by discussions on seaweed farming in Tanzania and elsewhere. Tanzanian researcher Dr. Matern Mtolera filled us in on seaweed cultivation in that country. He pointed out that most farming is done on the east coast of Zanzibar (or as it is also called, Unguja Island) because the rainfall is lower there. The main species cultivated are Eucheuma denticulatum (industrial name “Spinosum” and a source of iota carrageenan) and Kappaphycus alvarezii and K. striatum (industrial name “Cottonii” and a source of kappa carrageenan).

A Zanzibari seaweed farmer ties thalli of Euchema and Kappahycus to nylon lines for planting, at Paje, on the east coast of the island.

Seaweed farming in Zanzibar started about 20 years ago, with the import of only 4 kg of E. denticulatum from the Philippines. Now 3% of the population of Zanzibar is involved in seaweed cultivation, and it provides 20% of Zanzibar’s export earnings, from the more than 30 000 tones dry weight of seaweed that is produced annually. Seaweed farming is mainly done by women, and has greatly empowered them. A Zanzibari man is quoted as saying that “We no longer marry the women - they marry us!”

There was a lively discussion about the problems that Tanzanian seaweed farming faces. Seaweed growth rates (especially Kappaphycus) are lower than in the Philippines, possibly because the water is about 2oC warmer in Zanzibar, and epiphytes are a perennial nuisance. Seagrass beds have often been displaced, losing their associated fauna and flora. Relationships between companies (who often fund the commencement of farming in villages, but then control production and to a certain extent, prices) can become strained. All current farming is done at low tides, in very shallow water, but it may be possible to expand operations by developing “deep water” farming such as is practiced at Nusa Lembongan, Indonesia. There cultivation is done in water 1-2 m deep. However, Tanzanian scientists and farmers are unanimous that such a development will require investment in research, and state assistance to get it started.

Two days before the end of the workshop the monsoon rains arrived in spectacular fashion. Water streamed off roofs, and the view of the sea disappeared in a gray curtain. The hotel swimming pool overflowed across the lawn and into the patio, where men with brooms tried to push it out again. Streets became shallow rivers, and our minibus taxi gurgled to a stop when one of the main roads into Stone Town became a canal. Fortunately, although water was everywhere, it was warm, and outdoor activities were limited to trying to reach the dining area without drowning. It was still raining when we left Zanzibar two days later.

The Zanzibar workshop was interesting and productive, and once again we were able to establish new connections with other African scientists, and hear first-hand about the work they are doing. It is a pity that the project has come to an end, but the contacts made during the many workshops will soon lead to constructive collaborations between African colleagues, such as the PSSA meeting proposed for Maputo in July 2006.

Robert J. Anderson
Seaweed Unit, Marine & Coastal Management
Dept. of Environmental Affairs & Tourism


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