Seawater Farming: A Solution for Rising Sea Levels, Food and Fuel Crises?

Carl HodgesBig problems require big ideas to solve them, but what about two massive predicaments? Is it possible to approach them together with one outsized, ambitious solution?

University of Arizona atmospheric physicist Carl Hodges thinks so, and his life's work hinges on taming the rising sea into irrigation channels that will transform barren coastal deserts into fertile sea farms that generate food, jobs, and wealth. His work in this field has earned Hodges the role of Frontline Pioneer in Climate Change as part of CNN International's Principal Voices roundtable, which will broadcast on November 22nd and 23rd.

If Hodges' remarkable vision, as outlined on the Seawater Foundation website, doesn't qualify as a big idea, I'm not sure what would. His scope is global, but the basic framework of the plan involves cutting channels to draw the ocean, which constitutes 97% of the Earth's water, into coastal desert areas that need irrigation. The channels will not only help drop rising sea levels, but they will also turn these barren regions into aquafarms for shrimp, fish, and shellfish. The outflow from that aquaculture will, in turn, irrigate and fertilize halophyte crops, or plants that thrive on saltwater. In Hodges' words,

"You cut a channel, but you call it a river, because it doesn't go on to a dead end. Instead the water goes in, and it irrigates things. When you stand at the mouth of it, you feel exactly like you would at the mouth of a river. Except you look down and the water is going in and not coming back. It goes in to produce animals, shrimp and fish, and then with their excrement involved, it irrigates trees that turn into forests. The forests have meadows of crops that provide food and fuel. And beauty. I think that's an important value." - CNN

Such a lofty goal actually has deep roots, both through Hodges' 25 plus years of research at the University of Arizona and his previous seawater agricultural project in the deserts of East Africa in 1999. Seawater Farms Eritrea (SFE) has fallen victim to political instability, but during its heyday in 2003, it provided jobs for 800 people, cultivated a couple hundred acres of seawater-tolerant crops, and produced enough excess shrimp for export. That's no small feat for a part of Africa susceptible to famine.

Descriptions of SFE during its peak describe even more benefits for the region:

"Construction began with a huge channel from the Red Sea. This saltwater river, wide enough for small boats, runs onto the land, providing water to the land-based brick and concrete circles in which we raise our shrimp, fills the three salt lakes that hold the bulk of our fish, nurtures the thousands of mangroves that will shade its shores, irrigates our field crops, and drains, finally, into a sea garden park. This park, forested by several varieties of mangroves, shelters innumerable species of flora and fauna; herons, flamingos, and other shorebirds, marine animals of many kinds, and even allows domesticated animals, like goats and camels, a place to graze." - The Seawater Foundation

sea asparagus At Eritrea, workers planted the powerhouse halophyte salicornia, also known as sea asparagus. This salt-loving succulent is a potential food source and an oil seed crop that can also provide a cooking oil, high-protein meal, and biofuel. Hodges' current project involves salicornia as well, this time in dry, arid Sonora, Mexico near the Sea of Cortez:

"The enterprise recently planted 1,000 acres of salicornia here in rural Sonora, where Hodges has been doing preparatory research for decades. That crop will provide seed for a major venture planned 50 miles north in the coastal city of Bahia de Kino. Global Seawater is attempting to lease or buy 12,000 acres there for what it envisions will be the world's largest seawater farm." - Los Angeles Times

And recognizing that people generally need financial reasons as well as ethical ones to invest in pricey solutions to thorny ecological problems, Hodges started Global Seawater, Inc. This for-profit company is raising capital for sea farms that will produce returns for investors around the world. One potential way to make the sea farms profitable is through sales of the biofuel produced from salicornia.

Feeding the world, reducing the chances of coastal devastation from rising sea levels, creating jobs and wealth, and transforming deserts into farmland is one heady miracle of a vision. Questions about the viability of large-scale seawater agriculture do exist in some quarters, especially in a region whose environment has already fallen victim to previous agricultural operations:

"Some environmentalists are dubious. Wheat and cotton flourished here until farmers pumped aquifers nearly dry. Shrimp aquaculture operations have fouled the Sea of Cortez with waste.

Channeling millions of gallons of seawater inland could have similar unintended consequences for fragile deserts, said biologist Exequiel Ezcurra, former head of Mexico's National Ecology Institute. "We have had catastrophes in the past, so we have reason to be concerned," he said." - Los Angeles Times

Elsewhere in the world, saltwater irrigation can't be introduced beyond coastal land already exposed to high salt content:

"Unfortunately, Seawater agriculture can only be confined to coastal deserts because if seawater were brought inland, it would ruin the land unaccustomed to the high salinity. Saltwater agriculture further inland would be a disaster" says Emanuel Epstein, a professor and highly respected researcher of plant biology at the University of California, Davis. - EcoWorld

For a sneak peak of what Hodges has already accomplished in Mexico before CNNi airs the full special later this month, check out the following video:



If you see any unhelpful comments, please let us know immediately.

Clive Kerr / (anonymous)

Is there any research being done on the South African coast?

Written in December 2008

ron vandenkerkhof/ (anonymous)

this is the best kept secret in the world get the word out there and i beleive that public support for these initiatives would exceed your wildest dreams i myself would love to be involved in anything at all to do with this very exciting potentially earth altering idea

Written in May 2009 (anonymous)

It seems impossible to get any real "How To" info from any of these types of people. Interviews and articles are all the same.
Is it a green Con?
If not please tell me who hasd the "how to" site.
mike barnard

Written in November 2009

Ron Larson (anonymous)

Re this sentence: <"Potentially, the mangrove could ultimately make the fuel carbon negative by helping the entire ecosystem capture more carbon dioxide that would get released when the fuel is burned, other speakers noted."> It is not clear why the system is carbon negative. Are they thinking biochar? If so, better to say the fuel will be pyrolyzed, not burned.

Written in January 2010

Christian Parlade (anonymous)

I would love to get involved with this initiative. Please look me up.

Written in April 2010

dion (anonymous)

i wanna know some solutions of sea level rise

Written in April 2011

Alicia Alwyn (anonymous)

Fascenating, I would like to see current information on this subject.

Written in October 2011

Bart Rehbein (anonymous)

My company Epic Green Solutions has been working with a subsurface irrigation system for over 10 years in the U.S. This system is lined with a waterproof epdm liner so no water is lost to the soil. We began trialing the system in the United Arab Emirates in 2007. We have ran successful trials with our system growing sesuvium with water pumped directly from the Arabian Gulf (salinity level 50,000 ppm plus) We are currently starting new trials with other types of plants. As the system also creates a desalinization effect we will be trialing things that do not normally work in a saline environment. Because we have a lined system we do not contaminate the soil underneath the system.

Written in October 2011

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  • Posted on Nov. 10, 2008. Listed in:

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