Bangladesh’s extensive coastline is a source of many marine resources, providing livelihood for millions of people. But it is still underused. One of its untapped potentials is seaweed cultivation. Experts say that taking advantage of this will not only contribute to the country’s economy, but it can also save the environment.
British entrepreneur Sahil Shah says the enormous size of the Bangladeshi coastline, among other factors, attracted him. He says that the suitability on Bangladeshi coastal waters for seaweed cultivation, a need for farming/fishing diversification, especially in the face of climate change, and availability of a plentiful coastal workforce indicate that it is worth looking into seaweed cultivation in Bangladesh seriously.
Sahil Shah’s company Sustainable Seaweed, a seaweed cultivation and processing business, leverages technology that enables seaweed to be grown at higher yields and with a lower labour requirement. The business was established at the end of 2017 and is currently focusing on sites in Europe and Asia.
For Bangladesh seaweed cultivation can be a great opportunity for future climate resilient investment. The FAO estimates that the global value of seaweed is around $6.5 billion a year, with 80% of this produced in Asia, where conditions are ideal. Currently however, very little is located in Bangladesh. Private research company GM Insights estimate that the global seaweed market will be worth over $85 billion in 2026.
And then there is environmental benefits. According to Australian climate scientist Tim Flannery, using just 9% of the ocean surface to grow seaweed would absorb all of global CO2 emissions, produce enough food for the world and meet global energy demand. Seaweed has many advantages: it is faster growing than any land based crop, more CO2 is stored in seaweed than any plant on land, and seaweed requires no land, freshwater or fertilizer to be cultivated.
“Cultivating seaweed by setting up a nationwide or regional seaweed industry in Bangladesh would have a wide range of associated benefits. Many of these will be for Bangladesh as a whole, but critically they will also serve individual smallholder farmers, their families and their local coastal communities as seaweed is suitable for small scale production,” said Shah.
But this will require investment, both from coastal communities as well as the establishment of drying and packing facilities to take full advantage of export markets. The good news is that these are well within the reach of Bangladesh.
The economic impact
Seaweed farming would provide a number of micro and macro economic benefits. For example, said Shah, red species of seaweed have an exceptionally short growing season to maturity (as short as 30-45 days), meaning as many as 6-8 harvests are possible each year.
This enables farmers to receive money as soon as 30 days after planting. Growth rates are high, with yields of 10kg/m2/harvest attainable. While prices vary along with the species, it is possible to earn TK12,000-14,000 per season on an investment of just TK1,200, according to a research paper published in the Journal of Marine Science Research and Oceanography.
Meanwhile, incomes of TK2.5 lakh every four months have been achieved, and given the scalability of seaweed cultivation this will be far from the maximum.
“Once additional drying and marketing investments are made and higher value seaweed varieties can be sold worldwide, we would expect these incomes to rise significantly, both for growers and processors,” Shah told Dhaka Tribune.
This allows seaweed farming to provide a supplementary income for fishermen, diversifying their risks. Moreover, seaweed farming is resilient to the depletion of fish stocks, and can even increase them by providing habitats and improving water quality.
Similarly, seaweed farms and prawn/crab farms are symbiotic, with seaweed absorbing excess waste from these farms, and actually growing faster, whilst cleaning the water. Combined with its climate resilience, this makes seaweed farming an excellent fit for many regions in Bangladesh, particularly in the south-east around Cox’s Bazar and along the west coast.
“Seaweed is also able to be carried out commercially at smaller scales than many other forms of aquaculture, and makes use of natural fertility rather than needing intensive inputs as with other forms of aquaculture. Initial capital costs are also low, and supply chain traceability is much less of an issue than with other products such as prawns. This means seaweed cultivation avoids many problems that Bangladeshi producers have struggled with in the past. As a result, once the industry is established the cultivation of seaweed would be suitable for all kinds of farmers across Bangladesh, both large and small,” Shah said.
The final macro benefit, says Shah, is export revenue. Large existing markets for seaweed exports exist, with Indonesia exporting $325 million of seaweed in 2019. Tapping into these existing markets could similarly provide a much needed boost to Bangladesh’s foreign currency reserves, and contribute to an improvement in the Balance of Payments position.
The social impact
As well as economic, seaweed farming provides a number of social benefits. It provides direct employment, through the farming, as well as through the supply chain, with jobs created at the hatchery phase, for seeding, drying and any further downstream processing if done domestically.
“Nearshore seaweed farming elsewhere in the world such as Tanzania is predominantly undertaken by women, and can be a source of female employment and empowerment, contributing to increased participation in the labour force and gender equality,” Shah said.
Finally, seaweed is an incredibly dense source of micronutrients such as iodine and Vitamins B12 and D, and can be incorporated into diets to reduce micronutrient deficiencies, which could also lead to improved health outcomes.
The environmental impact
Seaweed farms are also highly resilient, and can make agricultural systems more resilient. Compared to land based agriculture, seaweed farming is not affected by flooding or by droughts, and temperature variation tends to be milder in the ocean than on land. Moreover, seaweed farms are less susceptible to climate change, with yields less likely to reduce with temperature rises and less exposure to climate related natural hazards.
Seaweed cultivation provides a number of environmental benefits. It absorbs excess CO2 in the ocean and in doing so reverses ocean acidification, which is beneficial for both general marine life and aquaculture. As well as CO2 absorption, seaweed absorbs both excess nitrates and phosphates in the water, often from either industrial waste or agricultural/fertilizer run-off.
Seaweed farms can also act as hubs of marine biodiversity, and provide a sheltering habitat for juvenile fish. “There are scientific studies showing that seaweed farms both improve fish health and stocks, thereby increasing the amount of catch for fishermen in the long run,” Shah said.
