Living Machines - Future Horizons

Future Horizons

In a 2000 report to the USEPA on a South Burlington, Vermont, living machine, Ocean Arks International outlined five key areas which could shape the future of this field. The foremost “possible breakthrough areas” is the ongoing classification of species by the biochemical, biological and ecological roles they play and how those roles effect other species under the context of wastewater treatment. The breakthrough would be to study the function of organisms in hopes of being able to more readily and successfully manage overall ecosystem function. Browne et al. (in press) have looked into the structuring of aquatic systems for water treatment.

Trophic management is used to influence entire systems by selective predation based on diagnosing an imbalance and analyzing the web of ecosystem classifications, roles and relationships. This management technique exploits the close interconnections of the food web, trophic cascade, to send a ripple down through the living community. This stewardship technique is predicated upon an advanced understanding of the conditions in the ecosystem and modeling the dynamic relationships down the trophic cascade. The trophic cascade in lakes has been researched by Carpenter and Hall.

Living Machine systems have been composed largely in closed greenhouses which can only react minimally with the surrounding ecosystem, and where populations have been heavily managed to foster equilibrium. If a Living Machine were subject to the ecology of invasions, new species would be free to colonize the system, and natural selection would dictate the success of any species. This would be true ecosystem self-design and self-management partnered with human stewardship.

Photosynthetic changes, specifically the control of light exposure is another powerful management practice capable of slowing or accelerating primary production. This is similar to the idea of trophic management, except that it manipulates the other end of the food web.

Finally, there is economic potential for methane generation, market crops such as flowers, fish, tomatoes, lettuce and other foods tolerant of hydroponic conditions, useful plants or medicinals. Combined with the revenue from wastewater treatment these services could turn living machines into pollution sinks and economic generators. It is well documented that a small, well-planned system in a good location can be economically viable. If a living machine can subsist in Alaska, it seems reasonable that ecologically engineered wastewater treatment can be tailored to work smoothly in warm developing countries.

Public sanitation and equitable access to water in very poor countries are grave problems. Living machines could be a low-capital approach to treating and recycling water, but skilled biologists may be a limited resource as well. A brick-pool living machine was built by Americans in Auroville, India.