Seaweed in Tanzania: A Multitude of Green Potentials


Seaweed farming in Zanzibar. Photo Credit: Kiki Streitberger

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The world has come to recognize seaweed as a sustainable super plant. Its reputation as a superplant is a result of both its ecological and economic advantages. The fast growing plant is capable of absorbing greenhouse emissions like carbon dioxide and nitrogen thus making it an effective tool in the fight against climate change.

Seaweed can be used to treat waste water and remediate nutrient polluted coastal waters or waters with excessive nutrients which can cause production of harmful algal blooms. Harmful algal blooms are simply marine plants that grow excessively which reduces the amount of dissolved oxygen in water bodies and deteriorates the quality of the water.

The waters of Tanzania’s Indian Ocean are teeming with a diverse array of seaweed species. This natural growing versatile plant is primarily harvested  on the islands of Pemba, Zanzibar and Mafia and to a much lower degree in the Tanga and Lindi/Mtwara.

Tanzania produces 92% of all the seaweed in Africa, making it the continent’s top producer. Seaweed farming is the country’s third largest industry primarily run by women who make up 80% of the 30,000 farmers the industry employs. In Zanzibar, contributions from the sector may be seen in the local health care system and household income, which empowers women and makes it possible for local children to go to school.

CP Kelco, a Huber subsidiary is one of the major global players in the seaweed market with investments in our local seaweed industry. A carrageenan producer, in the company sources its red seaweed from Zanzibar. In collaboration with ZANEA Seaweed company, the U.S based company

The History

The 1980s are mistaken to be when Tanzania started trading in seaweed. But history shows us that Tanzania seaweed trade dates back to 1940, with Pemba, Zanzibar, and Mafia islands  serving as the main hubs for its collection from the start. By 1951,Zanzibar was trading seaweed internationally with 387 tonnes of dried seaweed shipped out.

By the late 1960s annual exports ranged from 500 to 800 tonnes dry weight, with most of it going to European markets. The exporters were independent businesspeople who bought the seaweed through a network of middlemen who bought seaweed from individual collectors in coastal towns.

The Zanzibar State Trading Corporation took over the export trade at the beginning of the 1970s, but due to its inexperience, it produced a product of poor quality, which contributed to the sector’s collapse. And even though the previous exporters had relocated to mainland Tanzania, they were unable to revive their trade. Eventually with the return of the private sector in the 1980 the trade began to improve with exports to Denmark, France, Spain and USA.

The Present

Even with the momentum the seaweed industry in Tanzania has gained, there is still untapped potential in exploring the commercial cultivation of other seaweed species found in Tanzania’s coastal waters. Tanzania, along with the rest of Africa, is falling behind in the global market despite being the continent’s top producer and the rising demand for seaweed in the wake of the climate change issue.

So far, atleast 428 species of seaweed belonging to the Rhodophyta, Chlorophyta, and Phaeophyceae have been identified in the country. And only a small portion of these, particularly the red seaweed species Eucheuma spp. and Kappaphycus spp., are grown commercially.

Seaweed has traditionally been used for human consumption and cosmetics. But now there is a growing demand for other uses of seaweed. The World Bank recently published a report on the new and emerging seaweed markets and mentioned 11 market sectors which include sustainable animal feeds, biofuels, pharmaceuticals and nutraceuticals. The growing demand is facing challenges like constrained seaweed supplies, regulations and climate change, to mention a few.

Read Global Seaweed New and Emerging Markets 2023 Report.

The industry in Tanzania is without its challenges. Seaweed farming has been declining most especially because of climate change and unsustainable farming techniques. The rising high temperatures and the increased frequency of diseases and pests  are some of the climate induced challenges. Seaweed farming has also been associated with school dropouts in Zanzibar. One of the causes of school dropouts in Zanzibar, according to a study published in 2022, was poverty, which led to the students’ turning to day jobs like seaweed harvesting as a way to make ends meet.

From My Point of View

Addressing the root causes of school truancy, however, requires a more comprehensive approach. A strategy that prevents children from accessing day jobs, however, could be one of the solutions as well as  implementing programs that provide financial support to families living in poverty, children may be able to prioritise their education over the need to work.

Seaweed farming has the ability to advance our green economy, support national economic expansion, and make us a more environmentally conscious nation. The industry can lessen rural-urban migration most especially from Mtwara and Tanga regions by engaging the youth, where they can be self-employed rather than going to towns in search of work. It merits investment because of its major contribution to reducing the effects of climate change on the nation.

It is imperative that Tanzania invest more in research and development of the seaweed industry. As indicated in the recently published 2023 report on new and emerging seaweed markets, there is an extensive knowledge gap in the global seaweed industry that is impeding its growth.

Investing in research will equip the public and private sector decision makers, entrepreneurs, and investors with data necessary for making more informed decisions on how to propel the global seaweed industry forward. R&D will enable the country to explore innovative uses of seaweed beyond traditional applications, such as biofuel production or pharmaceutical development.

Additionally, it is essential for the government to foster favourable conditions for domestic production of products related to seaweed. This will enable Tanzania to tap into the growing global demand for seaweed-based products, such as cosmetics and food additives; reduce its reliance on imports, create job opportunities for its citizens and reduce carbon emissions as a result of exports.

Because the industry is dominated by women, the government should take advantage of these favourable circumstances to further empower girls and women in the country. Government funding should go toward developing female experts on seaweed.By incentivizing and  providing them with access to training programs, financial resources, and market opportunities, Tanzania will not only enhance the seaweed industry but also promote gender equality and economic inclusivity.

The industry can lessen rural-urban migration most especially from Mtwara and Tanga regions by engaging the youth, where they can be self-employed rather than going to towns in search of work.

Read more Climate change insights by Suzie Berya here.

A writer and a champion of change and sustainable development. She writes on climate change, gender justice and equality, human rights, education, Tanzania and the wider region of Eastern Africa.

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