Engineered Ecosystems, a Cyborg Approach to Ecosystem Restoration – Grand Lake St. Mary's Littoral Wetland Restoration

Joseph Pfeiffer, Jr. SPWS, Ecosystem Dynamics Practice Leader, KCI Technologies Inc.

Direct modification of an ecosystem as a whole is beyond the technological, physical and financial limitations of society. However, the resilience of the processes within the ecosystem can be used to synergize an effect on the system as a whole given proper nurturing and support. The initiation of this process may require establishing a symbiotic relationship between engineered systems and natural infrastructure specifically designed and calibrated to enhance targeted ecosystem processes that will yield exponential response within the ecosystem.   The created “cyborg system” serves the greater good of the objective by establishing seeds of stable processes that become the foundation for self-sustaining ecosystem restoration.

This approach was  applied to the restoration of the Grand Lake St. Marys (GLSM) Ecosystem.   Nutrient loading from the contributing watershed has created hypertrophic conditions within the 21 square mile lake ecosystem.   Radical swings in water clarity and temperature fuel massive blue green algae blooms that create a cascade of impacts to system processes, disrupting biological, chemical, and societal services provided by the lake. The frequency and severity of the blooms indicated the system was on the verge of ecological collapse.

GLSM historically supported 2,500 acres of littoral fringe wetlands that maintained a healthy equilibrium, processing nutrients and providing habitat.   Loss of the littoral wetland system through anthropogenic actions and invasive species (carp) stressed the system to the breaking point.   A series of Constructed Wetlands (Engineered Ecosystems) were established to address the limiting factors to the restoration of the littoral wetland system by targeting water quality degradation.

These systems removed nutrients via a series of interlinked engineered, bio-technical, and natural treatment systems.   Water is pumped through the systems at the rate of several million gallons per day, the water is treated by a series of systems including alum injection, constructed wetlands, and restored naturalized wetlands, prior to being discharged back into the lake through a embayment/constructed littoral wetland.   The improvement in water quality provided the conditions needed for natural regeneration of littoral wetlands beyond the influence of the engineered systems.


Author Bio

Mr. Pfeiffer is a Senior Professional Wetland Scientist (SPWS) with 32 years of experience in environmental/engineering planning. His expertise includes watershed planning and ecological restoration, wetland design and construction management. He holds a Master of Arts in physical geography and environmental planning and a Bachelor of Science in natural science.