Engineered Ecosystems in Water
Another important set of engineered ecosystems occurred in water. In the Pacific Northwest, Indigenous nations created clam gardens. Normally the ocean creates a sloping shoreline with a tiny clam population. By creating rock walls of proper height, sandy shallows perfect for clams can be created. Archaeologists have dated some back 5,000 years. In Alaska, “stream sculpting” by native peoples was used to increase salmon spawning grounds.
The Mayans and Aztecs developed a system called chinampas, in which plants grew on rafts on the surface of a lake. With roots in nutrient-rich water rather than soil, this may have been the first example of aquaponics. These eventually turned into a complex of stationary islands, floating gardens, and canals.
Lake engineering of a different sort occured in Anishinaabe ricing nations of the Northeast. In the 1900s, the Canadian government created Whiteshell preserve in Manitoba, and prevented the local Iskatewizaagegan nation from their traditional gathering of wild rice. As a result, they had to establish new ricing lakes--a practice western anthropologists had never observed before. They did so by controlling water levels, maintaining sufficient depth to prevent other species from competing, but not so deep that it diminished rice harvests. Biologists have recently shown that the wide areas covered by wild rice are likely examples of engineered landscapes, as Indigenous practices helped to spread and maintain rice areas.
In this simulation, a Native Nation has decided to create a wild rice experience for green tourism. If too many tourists arrive, their waste causes eutrophication (too many nutrients leading to algae explosions). If too few, not enough rice gets harvested. Can you find the balance? Click on the green flag at upper right to start. Up arrow for more tourists, down arrow for less.