The study of basic ecology has been the inspiration and foundation for the design of ecologically engineered systems. The days of the “gentleman naturalists” from the 18th and 19th centuries who primarily studied individual species in a reductionist approach eventually gave way to the ecologist who appropriately fit species, populations and communities into their complex and interrelated environmental context, giving rise to important theories that have withstood the test of time. Ecological engineering has evolved from the minds of modern ecologists who have tested theory and proposed solutions using ecosystems to support human societal and environmental goals for the benefit of both in an applied, “engineered” way. The great systems ecologist, H.T. Odum, first developed the concept of community engineering in 1957, later coining and defining the term ecological engineering in his first book on energy systems theory in 1971.
Much like the emerging science of biomimicry in design, ecological engineering uses ecosystems to solve problems, with the solutions embedded in the seemingly unlimited, and sometimes secretive knowledge found in the natural world. If ecosystems are the inspiration and template for ecological engineering, species populations are the living tools of this discipline applied in tandem with conventional technology. The connection of these “dots” is not often instantly evident.
Biohabitats, as its name implies, applies the foundational knowledge of research in how natural systems function in order to solve societal and environmental problems. Several of the innovators in ecological engineering have paved the way for some of the interesting work we are doing today. These innovators often have a broad background in systems thinking but also possess the detailed knowledge of the systems they study that allows them to make the intellectual leap to develop ecologically engineered design solutions to real world problems.
Dr. Walter Adey of the Smithsonian Institution took inspiration from algae-covered coral reef heads when he was designing a coral reef model at the Natural History Museum. With the challenge of maintaining specific water quality conditions for the highly sensitive organisms in his tanks, he found he was unsuccessful in using commercially available filtration systems. While on a collecting trip off the coast of Belize, he noticed that the tops of reefs he was surveying were covered in algae, despite the fact that this was a tropical, nutrient- limited environment. By transferring samples of the algal turf into the water treatment branch of his reef microcosm at the Smithsonian, and applying the appropriate high light intensity during the hours while the model reef was in darkness, he created an entirely new water treatment mechanism.
Dr. Adey explains, “From our experience with both the wild and the microcosm algal turfs, we concluded that we might make this work if, along with high light intensity, we supplied wave action, water flow, a porous surface (to prevent overgrazing) and constant harvesting (to prevent community succession). Thus, we created a device called “the algal turf scrubber” and attached it to the 7kl system late in 1979. The algal turf scrubber was extraordinarily successful, in that it achieved primary production rates characteristic of a wild reef, and also simulated the effects of high-quality ocean water by adding oxygen to the system and scrubbing nutrients from it. Most important, it could be operated at night, when water quality is likely to decline, and it was controllable in many ways, since by adjusting light, wave action, water flow and harvest rates we could maintain water chemistry in the microcosm reef much as ocean flow maintains it in the wild.”
Staff at Biohabitats has been significantly influenced by Dr. Adey and his inspired use of the principles of ecological engineering. With his support and that of a company he works with (Hydromentia), we conducted pilot projects at a wastewater treatment plant o New York City’s Jamaica Bay for the NYC Department of Environmental Protection. Scale-up designs are in progress, as is the production of sample volumes of ethanol, butanol and biodiesel as biofuels from the algal biomass.
In Baltimore’s Inner Harbor, we completed a year-long study (in collaboration with Dr. Patrick Kangas of the University of Maryland) running highly nutrient rich harbor waters impacted by low dissolved oxygen through an algal scrubber. This data is being used to inform a model creating oxygen refugia zones in the harbor to buffer the effects of periodic fish kills. The algal biomass harvested from the scrubber has been shown to be effectively converted into a bio-oil, biochar and a syngas.
The project, operated adjacent to the Living Classrooms Foundation’s Crossroads Middle School, inspired students to create a model scrubber for furthering a curriculum focused on science, technology, engineering and math. More pilots and feasibility studies of the use of the scrubber to support of nutrient reduction goals are in the works. We believe the use of these simple, ecologically engineered systems inspired by nature have a bright future.
Many of us have also been influenced by the work of pioneering ecological engineer, John Todd. The co-founder of the New Alchemy Institute in the 1970s found inspiration in natural systems and developed what he called the living machine. Principle elements of the organization and these systems involved energy systems, architecture and sustainable agriculture.
John Todd relates, “For over fifteen years, beginning at New Alchemy, I had raised fish and had learned innumerable tricks to purify water in order to keep the fish healthy. It seemed logical to use the same biological techniques and apply them to purifying water, sewage and other waste streams. An ecosystem approach, while dramatically different from conventional waste engineering, seemed to me to be the best long-term solution to upgrading water quality…”
The effects of these influences on Biohabitats’ work are found in the many projects that include the use of wetland ecosystems as models for water and wastewater treatment. For example, we helped the Sidwell Friends School in Washington, DC treat all of its wastewater through a series of wetland cells located at the school’s main entrance. The treatment wetland eliminates millions of gallons of municipal sewage treatment pressure on the city and resupplies toilets with sterilized, naturally treated, reuse water instead of potable water. It has also inspired school science, art, and drama classes with its function and beauty.
Recently, we collaborated with the Waterfront Partnership of Baltimore and the Living Classrooms Foundation to design and create floating wetland islands in Baltimore’s Inner Harbor. This project not only provided hands-on education for students and educators, its use of discarded plastic bottles found in the harbor as the floatation device reminds the Harbor’s millions of annual visitors of the impact that upstream society has on water quality downstream.
Solving real world problems with ecological engineering while providing an education in responsible living, science and art…all inspired by nature. Now that’s a beautiful thing to mimic.