Hiking alone as a woman in the Andes can be intimidating. Before heading out of my adobe homestay perched at 4,100 masl. (14,450 ft.) I nervously asked my host Mario if I needed to watch out for any personas perilgrosas (dangerous people). A perplexed look shot across his face, and he replied with emphasis, "no, es muy tranquilo aqui" (it's very relaxed here)
After a few hours of trekking in the pristine mountainous environment, it dawned on me how silly I must have sounded to Mario. I hadn't encountered any other living beings except free-roaming herds of alpaca and sheep who were all consumed with chowing down on ichu grass and a hawk circling above me looking for prey. Shortly after, I spotted, the hawk's target, a native squirrel-esk animal called a viscacha. The point is, there was not another person in sight, let alone a person that might want to do me harm.
I eventually arrived at a shallow lake nestled in a valley between two peaks. In the distance, I could make out the figure of a person wading knee-deep in the water. At first, I was apprehensive about approaching, but I couldn't turn back at this point. I need to pass the lake to reach the area where Mario told me wild potatoes might be growing. I slowly walked towards the lake. To my surprise, I discovered that the person was a small woman probably over 95 years old.
With a perfectly straight spine the woman bent herself over the surface of the water. She was moving something submerged under the water back and forth. At first, I thought that she was washing clothes. However, after a few minutes, she didn't stop to wring anything out. I wondered what she could be doing standing bent over in cold water for so long. Then memories from the previous Sunday market flooded my mind. I bet she is harvesting those odd algae pearls that I saw the mamitas selling.
I walked up to the lake's edge. The woman paused and twisted her body up to look up at me. With a twinkle in her one and only eye and a smile that reached ear to ear, she communicated a non-verbal yet friendly hello. Then, she quickly went back to work and continued to dip a woven bag into the crystal-clear water.
She created small currents by gently moving the bag back and forth, which loosened the pearl-shaped translucent spheres from the lake's shallow floor. Once they floated towards the surface of the water, she scooped them up with the bag. She repeated this sequence of actions so effortlessly while I sat there and watched.
This woman was harvesting cushuro or Nostoc commune, which is not an alga but rather a cyanobacterium, like spirulina. The 'blue-green' organism obtains its energy from photosynthesis like a plant. However, because it does not have a membrane surrounding the nuclei of its cells, scientists have classified it as a prokaryote [1]. Nostoc commune grows in rivers, lakes, and streams around the world. In the Andes, it is found growing in high-altitude bodies of water at 3,600 masl. (11,811 ft.) and above. To the rural communities living there, the abundance of cushuro coinciding with the start of the rainy season is a biological indicator that a promising agricultural season is in store.
The woman's movements told me a story. Her rhythmic and coordinated motions seemed to be in sync with her surroundings rather than separate from it. Her knowledge of how to harvest this wild food resource from the landscape was embodied. I imagined how she must have learned as a little girl from her mother or grandmother and how the lineage of this practice must have traversed back through the generations. This lady, whose name was unknown to me, probably ventured out to this lake to harvest cushuro for more than half a century.
According to Gantar and Svirčev (2008), cyanobacteria has been part of non-Western diets for thousands of years. From Mongolia to Mexico, the consumption of cyanobacteria has been a nutrient-dense supplement to traditional foodways. Studies have found that some strains of cyanobacteria contain up to 78% protein and are a rich source of essential vitamins like B-12 and provitamin A [2]. Numerous researchers have also found promising strains with anti-cancer properties [3]. Thus, these organisms are a nutritional resource and a potential source for new pharmaceutical compounds.
However, before you go try to harvest your own, you need to exercise caution. Some cyanobacteria strains can produce potent neurotoxins if grown in environmentally contaminated areas [4]. For example, malevolent cyanobacteria bloomed in Guatemala's Lake Atitlán due to eutrophication. The condition where excessive nutrient content, frequently caused by runoff, causes a prolific and dense growth of plants which kills animals and other organisms by lack of oxygen. In Lake Atitlán, the extra nutrients came from the indiscriminate use of industrial fertilizers on nearby cropland [5].
Eventually, the woman left the water to sit next to me on dry ground. We shared coca leaves and giggles. She chatted me up in Quechua and did my best to keep up the conversation in the few words of the indigenous language that I know. I pointed to her bag of treasures and exclaimed sumaq ancha (very lovely). She responded arí (yes). We both agreed that the weather was chiri (the Quechua word for cold that sounds almost exactly like English's chilly).
I decided to continue on my journey. The rocky slopes in the distance looked like prime wild potato habitat. While heading towards my destination, I experienced profound gratitude that I could meet this not-so-dangerous person.
After a full day of walking up and down steep slopes to gather spatial and biophysical data on two species of wild potatoes, I circled back around the lake on my way to the homestay. She was still out in the water harvesting her pearls. I waived to her, and she looked up and smiled and then continued her work.
People have enjoyed cyanobacteria as a nutrient-dense food source in ancient and present-day societies for centuries, with no report of harmful effects on human health. Andean communities use it as a flavoring element in traditional potato preparations or with the native legume tarwi. At Sunday market, the mamitias who sell cushuro, along with medicinal plants and mushrooms, reach into the bag and eat the pearls by the handful as a mid-afternoon snack.
The following Sunday after this encounter, I bought roughly four ounces for one PEN (≈ $.33 USD). I added it to the quinoa soup dinner that I was preparing for dinner. The flavor is mostly neutral, with a hint of kelp. However, texturally they are more exciting. We imagined making cyanobacteria bubble tea or soaking them in ceviche juice and making faux caviar.
References:
1. Cohen, Z. (1986). Products from microalgae. In Richmond, A. [Ed.] CRC Handbook of Microalgal Mass Culture. CRC Press, Boca Raton, Florida, pp. 421–54.
2. Aaronson, S., Berber, T. & Dubinsky, Z. (1980). Microalgae as a source of chemicals and natural products. In Shelef, G. & Soeder, C. J. [Eds.] Algae Biomass: Production and Use. Elsevier⁄ North-Holland Biomedical Press, Amsterdam, pp. 575–9.
3. Gantar, M., and Svirčev, Z. (2008). Microalgae and cyanobacteria: Food for Thought. Journal of Phycology 44 (2): 260-68.
4. Namikoshi, M., Sivonen, K., Evans, W. R., Carmichael, W. W., Sun, F., Rouhrianen, L., Luukkainen, R. & Rinehart, K. L. (1992). Two new L-serine variants of microcystins-LR and RR from Anabaena sp. strain 202 A1 and 202 A2. Toxicon 30:1457–64.
5. Rejmánková, E., Komárek, J., Dix, M., Komárková, J., & Girón, N. (2011). Cyanobacterial blooms in Lake Atitlan, Guatemala.Ecology and Management of Inland Waters 41(4): 296-302.
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