|Planting New Mangrove Forests|
Editor’s note: The earth is a thirsty planet, since over a third of the world’s population can barely get enough water to fulfill basic needs such as hydration and hygiene. But while fresh water is often in short supply, the earth is over 70% covered with salt water. What if salt water were able to irrigate farmland? How would that change the ironclad equation whereby fresh water and energy are the prerequisites for life and prosperity? A little-known experiment in the far-flung country of Eritrea could be the harbinger of radical changes in the malthusian notion that we don’t have enough water. Seawater farms, an operation founded by U.S. entrepreneur John Sperling, has taken the abundant and heretofore unusable resources of salt water and desert to create a managed plantation that produces, cost-effectively, fish, shrimp, lumber, and a nutritious plant, Salicornia, that thrives in salt water. Science could soon add many other plants to the list of salt-water crops. The potential is immense.
Many of us don’t realize how lucky we are to have access to all the water we want. Showering or bathing every day, dishwashing with the faucet on full blast, or owning a swimming pool is unthinkable in many countries. Water is not divided equally around the world. While Americans happily feed koi in backyard ponds, others in the Middle East or Africa, for example, have to wait for a truck to deliver their monthly supply of water. Walking five miles to the nearest community well and back is not an uncommon practice in these regions. “I’m not convinced that there are water shortages as much as there are problems with water distribution” says Linda Platt, an editor at the Political Economy Research Center (PERC), who like many of us, believes that many regions are at a disadvantage when it comes to water availability for farming, drinking, or simple hygiene.
With oceans covering more than 70% of the earth’s surface, it is ironic that usable water is not an abundant commodity. Less than 1% of water on the planet comes in the exploitable form of lakes, streams and groundwater. The potential of saltwater has been contemplated for years, but only recently have there been advances in operations that utilize this abundant resource.
|Eritrea has deserts and coastline
perfect for salt water agriculture
Carl Hodges, an atmospheric physicist at the University of Arizona, came up with an ingenious plan to overcome the freshwater shortages that many farmers face in arid countries. This plan, financed by University of Phoenix founder John Sperling, came in the form of Seawater Farms. “This project is still in the experimental stages,” says Linda Platt, editor of PERC, “but Seawater farms seems to have found a way to produce environmental goods without overexploitation of the environment.” Seawater Farms, established in the small African country of Eritrea, uses saltwater to sustain an array of shrimp, fish and plants. Amazingly, it doesn’t stop there: The remaining water even irrigates and sustains wetlands and mangrove forests that naturally occur in the region. They have also planted numerous trees in the hopes of establishing habitats for the fauna in the region.
“The life the mangroves support is tremendous,” says Jugal Tiwari, staff ecologist of the Seawater Farms and the Seawater Forests Initiative. “I have seen at least 100 species of insects, including 4 species of butterflies and 12 species of moths. Doves, Warblers and Prinias nest in the mangroves a well, and there are at least 14 different kind of crabs, including fiddler crabs. This year over 1 million seedlings were raised by the foresters of Seawater Forests Initiative. Each of the 15,000 mangrove plants we have planted in the 10 hectares of area is supporting a lot of life.”
“The number of bird species that have come to inhabit our farm has grown from an estimated dozen to well over 200,” says Howard Weiss, also of the Seawater Forests Initiative.
|Mangrove Forest in Eritrea|
“The mangroves are equally important in sequestering the atmospheric carbon and making environment pollution free,” says Jugal Tiwari, “We are basically a group of people who think global and take the challenge of converting the so called coastal wastelands (4.2 million hectares of such coastal wastelands in Eritrea) into green land using just the ocean’s salt water. As you know fresh water in such areas is a limiting factor and so deficient that people can’t find enough water to survive.”
The farming system is quite effective: Untreated salt water is brought inland through a 3-mile long canal to salicornia fields which, unlike most crops, are able to grow efficiently in this salty environment. The principal field crop, Salicornia, provides a gourmet vegetable from its young shoots. The mature plant provides seed that produce a fine, edible oil and a high protein meal. There is also a large amount of biomass, which can be used for animal fodder, particleboard, and firebricks.
Not all seawater flows directly to these plants; some diverges and flows into shrimp tanks and later 3 salt lakes containing different species of fish. The shrimp species Penaeus vannamei is the gem of Seawater Farms Eritrea aquaculture. This species tolerates variations in salinity, temperature, pH and oxygen levels that allow it to be as suited to farming as it is profitable. Another species of shrimp, Penaeus indicus, arrived in seawater farms unexpectedly through the seawater canals connecting the farms to the red sea. This added little bonus, with its popular flavor, has been a big boost to Seawater Farms’ business.
|The Tilapia Fish is Farmed Worldwide|
Fish were also incorporated into this intricate project. Originally, the plan was to just farm the tilapia fish. This useful species, naturally occurring in the Middle East and Africa is now farmed worldwide. At seawater farms, these fish are not just a food product; Their skin is similar to leather when dried and is used to make a variety of products whereas the leftover heads are recycled for shrimp feed. Another species of fish, the milk fish or chanos chanos, unexpectedly rode in on the seawater stream and has now established itself in the shallow waters of the mangrove park in addition to the tilapia. This is yet another bonus for the Farm.
The waste from the shrimp and fish is carried by water to fertilize the salicornia fields. This versatile agricultural system has worked extremely well, while the reestablished wetland parks, created by the overflowing seawater, are very much appreciated by wildlife residing in the area. No seawater is wasted either: It is absorbed by the soil and returns to its starting point-the red sea.
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.
|Salt Water Agriculture
A Field of Salicornia
Epstein has also had a fair amount of success with saltwater agriculture during the 1970s and 80s. “Why not start out with plants that are already economically useful such as wheat and rice which feed 2/3 of mankind instead of imposing economic usefulness on other plants such as salicornia,” says Epstein. “I was fairly successful in harvesting barley, wheat and tomatoes selected and bred for salt tolerance.” The scheme discussed [regarding salicornia] starts with naturally occurring wild plants. “An alternative approach,” continues Epstein, “is to start with established crop species, such as wheat or rice, which are salt sensitive, and by means of genetic and molecular biological methods engineer salt tolerance into them. The feasibility of this approach was demonstrated over 30 years ago at Bodega Marine Laboratory, with wheat, barley, and tomatoes and the likelihood of success has greatly improved since then as a result of the spectacular advances in molecular biology.”
Seawater Farms currently focuses on salicornia fields but genetic research funded by John Sperling is being done in the hopes of using other more ‘profitable’ species in this type of agriculture.
Seawater Farms is both ecologically acceptable and profitable. The first shrimp harvest, for example, was worth nearly 12 million dollars. Seawater Farms has also revolutionized coastal agriculture as we know it. It has given hope to farmers who are limited by the lack of freshwater available while the Seawater Forests Initiative has breathed life into forests that reside in an otherwise dry, desert environment.
EMAIL TO THE EDITOR
From: Jane Poynter [mailto:firstname.lastname@example.org]
Sent: Wednesday, December 03, 2003 4:57 PM
Subject: Seawater Farms and Forests
In your great article about salt tolerant crops, featuring Seawater
Farms Eritrea and Seawater Forests Initiative, I would like to point out
a discrepancy in the quote by Epstein regarding genetically engineering
standard crops, such as wheat and tomatoes, for salt tolerance. He is
referring to something quite different from what salicornia can do. Salt
tolerance in his context means plants that can grow in water that would
be too salty to grow normal agricultural crops, but is far less saline
than pure seawater by many parts per thousand. Salicornia bigolovii,
which has been bred to produce a high quality oil seed, grows on pure,
untreated seawater. Something quite different altogether.