Primary production: Freshwater ecosystems
- Cite this article as:
- Likens, G.E. Hum Ecol (1973) 1: 347. doi:10.1007/BF01536731
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Freshwater bodies include a small fraction of the earth's surface (0.5%) and the biosphere's production. Freshwater productivity is difficult to estimate because of both problems of measurement and the great diversity of water bodies. A total production of 1.3×109 tons/year is suggested. Freshwater bodies are now subject to widespread unnatural fertilization or cultural eutrophication. While this process increases their productivity, in many cases it shifts that productivity into forms less suitable for use as human food.