Perhaps you are asking yourself: why should we discuss seawater irrigation?
The simple answer is: due to the impacts of climate change, the world is seeking renewable sources of energy as alternatives to a fossil-fuelled energy matrix. By the same token, we should be considering alternatives to irrigation from freshwater. Only around 0,5% of freshwater is directly available for human consumption and 70% of freshwater withdrawals are consumed by agriculture. Yet, saltwater drenches 2/3 of our planet, not to mention saline groundwater which underlies much of the land. Also, there are about 20,000 linear miles of sunny, desert seacoast with untapped potential. Bearing this in mind, let us focus on a specific challenge, or opportunity: desert economics. No, this is not about oil being pumped out of the earth!
I came across a documentary called ''The greening of Eritrea'' which I thought would be interesting to share. It follows the development of a seawater farm project conducted by Dr. Hodges together with the government of Eritrea to establish the world's first commercial seawater farm, back in 1998. In a country which suffers from severe malnutrition and poverty, this was not a minor accomplishment. Political instability, however, led to the discontinuation of the project, in 2003.
Eritrea's economy and agricultural sector have been severely threatened by the combination of war, droughts, and land degradation. Eritrea has one of the highest child undernutrition levels, with the second highest score reported for the Global Hunger Index in 2014. Like many sub-Saharan African countries, the majority of the population depends on agriculture, which is mainly smallholder based and rainfed. Coupled with low total rainfall, insufficient access to seeds, soil and water erosion due to unsustainable land use practices, poor infrastructure and underlying poverty, the country's food supplies are unreliable and insufficient.
Seawater irrigation showcases systems thinking approach, creating a self-sustaining ecosystem which has the potential to revitalize the arid seacoast, creating jobs and increasing livelihoods.
I came across a documentary called ''The greening of Eritrea'' which I thought would be interesting to share. It follows the development of a seawater farm project conducted by Dr. Hodges together with the government of Eritrea to establish the world's first commercial seawater farm, back in 1998. In a country which suffers from severe malnutrition and poverty, this was not a minor accomplishment. Political instability, however, led to the discontinuation of the project, in 2003.
Eritrea's economy and agricultural sector have been severely threatened by the combination of war, droughts, and land degradation. Eritrea has one of the highest child undernutrition levels, with the second highest score reported for the Global Hunger Index in 2014. Like many sub-Saharan African countries, the majority of the population depends on agriculture, which is mainly smallholder based and rainfed. Coupled with low total rainfall, insufficient access to seeds, soil and water erosion due to unsustainable land use practices, poor infrastructure and underlying poverty, the country's food supplies are unreliable and insufficient.
Seawater irrigation showcases systems thinking approach, creating a self-sustaining ecosystem which has the potential to revitalize the arid seacoast, creating jobs and increasing livelihoods.
Too good to be true?
There are two basic questions regarding desert economics which must be addressed. Firstly, does salt water allow for plant growth? The answer is yes, and abundantly, just think of seaside mangroves. One halophyte (salt-tolerant plant) in particular, Salicornia, was successfully produced in Eritrea's seawater farm project and has great benefits and potential. Salicornia is a sea vegetable rich in minerals and vitamins A, B1, B15, C, and D. This plant is also a great source of oils and can eventually be produced to power jets, as Bilal Bomani, a senior NASA scientist believes:
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| ''So we talk about ideas worth spreading, right? How about this: In sub-Saharan Africa, next to the sea, saltwater, barren desert: how about we take that plant, plant it, half use for food, half use for fuel. We can make that happen, inexpensively'' - Bilal Bomani's TED TALK: Click here to watch! |
Dr. Carl Hodges, the scientist behind the initiative, argues that Salicornia grown in desert regions can potentially replace today's soy production, eliminating one of the main threats to the sustainability of rainforests. If adopted on a global scale, seawater irrigation could even contribute to reducing rising sea levels.
So how does it work?
The desert transformations proposed by seawater farming are ambitious, aimed at creating a self-sustaining ecosystem which harbors flora, fauna and biodiversity. To do so, however, would be impossible without investments in infrastructure, namely, the digging of canals and lakes.
The desert transformations proposed by seawater farming are ambitious, aimed at creating a self-sustaining ecosystem which harbors flora, fauna and biodiversity. To do so, however, would be impossible without investments in infrastructure, namely, the digging of canals and lakes.
A first canal with pumps that lift the seawater is needed and a secondary series of canals and lakes become home to a flourishing aquaculture of fish, shrimp, and mollusks. The biological waste from the aquaculture activities become the fertilizers needed to support the production of Salicornia. Nothing is wasted; the resulting water irrigates lands, replenishing depleted wetlands, revitalizing mangroves and ecosystems which provide essential and valuable services. A veritable virtuous circle.
According to CN Hodges, in its four years of operation in Eritrea, the Seawater Farms project planted 250 acres of Salicornia and nearly 240 acres of seawater forest. The exportation of shrimp was an additional value which provided incomes and employed nearly 800 people.
According to CN Hodges, in its four years of operation in Eritrea, the Seawater Farms project planted 250 acres of Salicornia and nearly 240 acres of seawater forest. The exportation of shrimp was an additional value which provided incomes and employed nearly 800 people.
Today, other countries are experimenting with Salicornia and other saltwater tolerant plants as sources of food! Of course, there still remain major challenges, ranging from political instability to setting up innovative financing schemes to support this revolution. In Eritrea, the main problem constraining development is the absence of an effective institutional capacity, water policies, and legislation to regulate water management (FAO).
For more information on seawater farming:
Cultivating Salicornia europea, Gunning, 2016
New Options for Climate-Defensive Food Production - Carl N. Hodges, 1980
Ending Global Poverty By Seawater - Planck Foundation
A Story of Regeneration and Reforestation From Eritrea - Circulate NewsCultivating Salicornia europea, Gunning, 2016
New Options for Climate-Defensive Food Production - Carl N. Hodges, 1980
Ending Global Poverty By Seawater - Planck Foundation
Greening Drylands with Seawater Easily and Naturally - Khaled Moustafa
Hi Candida,
ReplyDeleteAnother fantastic post. You outlined the statistics at the start of your blog post very well. I'm not sure you if you already know this, but did you know that of the freshwater percentage that you quoted, a further 68.7% of that is locked up as ice in the Arctic and Antarctic regions (Shiklomanov 1998)? Thought-provoking isn't it?
However, I'm intrigued as to how seawater irrigation could even contribute to reducing rising sea levels? Do you mean to say that it will cause localised flooding? And secondly, do you think this problem of sea level rise would be an imminent threat?
Best wishes,
Anparasan
Hello Anparasan, thanks for your comment!!
DeleteIncluding the water stocked in ice caps, the amount of freshwater available is about 2,5%; however, I said 0,5% is available directly- which I believe is more or less correct. In any case, the figures are indeed incredible!
Thanks for the question, I realise it's a bold statement and I should've made it more clear. I imagine that taking sea water inland (in a large scale) could remediate the effects of flooding under a small rise of sea level. I have to say, I couldn't find any further explanations! I read that Carl Hodges, the scientist I referred to, wants to use the drained coastal aquifers as giant storage tanks of sea water, but I'm not sure I understand how this is good or safe in terms of groundwater salinity. I imagine soil types play a major role.