• In the Beginning... were blue-green algae.
• Thousands of algal species cover the Earth.
• Algae through human history.
• Rediscovery of human use-Kanembu and Aztecs.
• Spirulina lakes and pink flamingos.
• A new era of ecological agriculture.
  

In 1940, a little known journal published a report by French phycologist Dangeard on a material called dihé, eaten by the Kanembu people near Lake Chad. Dihé is hardened cakes of sun-dried blue-green algae collected from the shores of small ponds around Lake Chad. Dangeard also heard this same algae populated a number of lakes in the Rift Valley of East Africa, and was the main food for the flamingos living around those lakes. His report went unnoticed.

Twenty five years later, a Belgian Trans-Saharan expedition discovered a blue-green material covering the waters around the shores of Lake Chad.

A botanist with the expedition, Leonard, came across curious blue-green cakes in native markets of Fort Lamy (now Ndjemena) in Chad. When locals said these cakes came from areas near Lake Chad, Leonard recognized the connection between the algal blooms and dried cakes sold in the market.

1.8. Collecting spirulina from a lake in Chad (photo J. Maley).

1.9. Spirulina cakes (dihé) on sale in a local market in Chad (photo J. Maley).

Desert winds pushed the mats of algae to the shores. Kanembu people collected the wet algae in clay pots, drained out the water through bags of cloth and spread out the algae in the sand to dry in the sun. When dry, women cut the algae cakes into small squares for sale in the local market. Dihé is crumbled and mixed with a sauce of tomatoes and peppers, and poured over millet, beans, fish or meat. It is eaten by the Kanembu in 70% of their meals. Pregnant women eat dihé cakes directly because they believe its dark color will screen their unborn baby from the eyes of sorcerers.12 Spirulina is also applied externally as a poultice for treating certain diseases.

At the same time, a company director in Mexico read about spirulina and realized it was the same algae clogging the soda extraction plant on Lake Texcoco. Although spirulina was not then eaten as a food in Mexico, an historical literature search revealed it was harvested, dried, and sold for human consumption 400 years earlier, at the time of the Spanish conquest.

Spanish chroniclers described fisherman with fine nets collecting this blue colored 'techuitlatl' from the lagoons, as seen in Figure 1-10, and making bread or cheese from it. Other legends say Aztec messenger runners took spirulina on their marathons. Techuitlatl was mentioned by naturalists until the end of the 16th century, but not after that. Probably, it disappeared soon after the Spanish conquest. The great lakes in the Valley of Mexico were drained to make way for the new civilization. The only remnant today, Lake Texcoco, still has an living algae culture.

1.11. Aztecs harvesting algae from lakes in the Valley of Mexico.
Drawing in Human Nature, March 1978. (article by Peter T. Furst).

Besides Lake Texcoco, the largest spirulina lakes are in Central Africa around Lake Chad, and in East Africa along the Great Rift Valley. Under normal water conditions, spirulina may be one of many algal species. But the more alkaline and salty the water becomes, the more inhospitable it becomes to other lifeforms, allowing it to flourish as a single species.

Lakes Bodou and Rombou in Chad have a stable monoculture of spirulina dating back centuries. It is a major species in Kenya's lakes Nakuru and Elementeita and Ethiopia's lakes Aranguadi and Kilotes. The lesser flamingo evolved a filter in its beak especially to eat spirulina. Millions of flamingos feed entirely on algae when it is abundant.

1.13. Pink flamingos in an African lake feeding on spirulina.

Spirulina thrives in alkaline lakes where it is difficult or impossible for other microorganisms to survive. Because the bacteria level in alkaline water is quite low, the bacteria count in spirulina, harvested and dried without further processing, is insignificant.13 Algae pioneers have dreamed of harvesting from these lakes to feed the millions of nearby hungry people now suffering from chronic hunger.

In natural lakes, the limited supply of nutrients usually regulates growth cycles. New nutrients come from either an upwelling from inside the earth, when rains wash soils into the lakes, or from pollution. The algae population grows rapidly, reaches a maximum density, and then dies off when nutrients are exhausted. A new seasonal cycle begins when decomposed algae release their nutrients or when more nutrients flow into the lake.

Over thousands of years, humans have dramatically increased food productivity, at progressively greater environmental costs. Domesticating plants and animals encouraged the first permanent human settlements. About 7000 years ago, irrigation brought water to the land and subsequent food surpluses supported the first great river valley civilizations. Thousands of years later, when the land salted up from over-irrigation, these civilizations vanished.

A thousand years ago, the invention of an efficient plough in Europe allowed easier tilling of the soil. Europeans cut down the vast original forests bringing new areas under cultivation and new prosperity to the continent. The 19th century industrial revolution introduced mechanized agriculture, climaxing in the so-called 'Green Revolution' exported from the United States in the 1960s and 1970s.

Modern agriculture has boosted short term productivity by using seed hybrids and massive fertilizer, pesticide, water and energy inputs. Productivity has been achieved by simply ignoring many hidden costs, such as the consumption of non-renewable fossil fuels for fertilizers and machinery, pollution of soil and water through excessive use of chemical fertilizers, and depletion of soils. This ecological damage will be paid by future generations.

Successful algae cultivation requires a more ecological approach to begin with. A pond of spirulina is a living culture and the whole system, not just a few inputs, must be considered. If one factor changes, the entire pond environment changes - quickly. Because algae grows so fast, the result can been seen in hours or days, not seasons or years like in conventional agriculture.

Algae scientists talk of 'balancing pond ecology' for sustainable growth. Pesticides and herbicides would kill many microscopic life forms in a pond, so algae scientists have learned how to balance the pond ecology to keep out weed algae and zooplankton algae eaters without using pesticides or herbicides.

Ecological food production is the next stage in agriculture. This represents both an increase in productivity and stewardship of the Earth's resources. Organic and biodynamic farming methods, permaculture, aquaculture and low tillage farming are practices now becoming more popular. Algae cultivation is a new addition to ecological food production.

A spirulina farm is an environmentally sound green food machine. Cultivated in shallow ponds, this algae can double its biomass every 2 to 5 days. This productivity breakthrough yields over 20 times more protein than soybeans on the same area, 40 times corn and 400 times beef. Spirulina can flourish in ponds of brackish or alkaline water built on already unfertile land. In this way, it can augment the food supply not by clearing the disappearing rainforests, but by cultivating the expanding deserts.

In one of the first books on microalgae, Spirulina, the Whole Food Revolution, Larry Switzer wrote:

"For the first time since the appearance of man, both wilderness and food productivity can be increased simultaneously with a new technology. This is a choice that man has never had before. The rediscovery of this ancient life as a human food has great implications for us all, now and in the 21st century. It is an example of the myriad of unexpected and astounding solutions to basic world problems that are now beginning to appear together on this planet."14

1. Lovelock, James. The Ages of Gaia. W.W. Norton&Co;., NY, 1988, p. 74.
2. Lovelock, p. 81.
3. Lovelock, p. 115.
4. Lovelock, p. 96.
5. Lovelock, p. 116.
6. Swimme, Brian. The Universe is a Green Dragon. Bear & Co., Santa Fe, NM, 1984, p. 137-8.
7. Kavaler, Lucy. Green Magic: Algae Rediscovered. Thomas Crowell, NY, 1983, p. 99-101.
8. Kavaler, p. 109-110.
9. Kavaler, p. 95-97.
10. Jassby, Alan. Spirulina: a model for microalgae as human food. Algae and Human Affairs. Cambridge University Press, 1988, p. 152.
11. Jassby, p. 153.
12. Ciferri, Orio. Spirulina, the Edible Organism. Microbio. Reviews, Dec. 1983, p. 572.
13. Ciferri, p. 578.
14. Switzer, Larry. Spirulina, The Whole Food Revolution. Bantam, NY, 1982, p. 12.