Blue green algae has been consumed for thousands of years by humans ,,,
Do we in part and all life on planet earth owe our existence to blue green algae?
From the first article/link below......
""""Historical Usage of Klamath Blue Green Algae
First a little background: Algae were the first life form on the planet and the first to achieve photosynthesis with the by-product of oxygen; setting the stage for life for all organisms. Even now, algae are still responsible for up to 90% of all photosynthesis on earth.There are over 20,000 species, ranging from unicellular to multicellular organisms such as the seaweeds – the largest and the most complex group of all. Algae as a food supplement have been used by people for thousands of years. Early civilizations including the Aztecs and African tribes used blue green algae as an additional source of protein.""""
""""Spirulina is a type of blue-green algae that grows in both salt and fresh water. It may be one of the most nutrient-dense foods on earth.This tiny alga is packed with nutrients. A single tablespoon (7 grams) of dried spirulina powder contains (2Trusted Source):
Protein: 4 grams
Vitamin B1 (thiamine): 11% of the RDA
Vitamin B2 (riboflavin): 15% of the RDA
Vitamin B3 (niacin): 4% of the RDA
Copper: 21% of the RDA
Iron: 11% of the RDA
It also contains decent amounts of magnesium, potassium and manganese and small amounts of almost every other nutrient that you need.
In addition, the same amount holds only 20 calories and 1.7 grams of digestible carbs.
Gram for gram, spirulina may be the single most nutritious food on the planet.
A tablespoon (7 grams) of spirulina provides a small amount of fat — around 1 gram — including both omega-6 and omega-3 fatty acids in an approximately 1.5–1.0 ratio.
The quality of the protein in spirulina is considered excellent — comparable to eggs. It gives all the essential amino acids that you need. """""
https://www.healthy.co.uk/blog/klama...gae-brain-food
https://www.healthline.com/nutrition...OC_TITLE_HDR_2
http://klamathvalley.com/
http://klamathvalley.com/aphanizomenon-flos-aquae/
Per the article stating that the Aztecs and African tribes were known to collect and consume blue green algae I'd say it would stand to reason that other peoples all over the planet including the Klamath peoples and the Paiute people and all sorts of peoples including the earliest known hominids and even apes figured out that we can collect this nutritious food source during specific times of the year like early spring and summer when it first becomes available and collect and consume it but should avoid collecting and consuming blue green algae when it potentially becomes toxic under certain conditions primarily during the heat of summer into fall.
I'll bet anyone I can dig up via a google search an article or some university master's or phd thesis research paper on the harvesting and consumption of blue green algae by the Klamath or Paiute peoples or other peoples throughout history.