Sawgrass marshes are part of the interdependent ecosystems that make up the Everglades, supporting aquatic invertebrates — crayfish and snails, and larval amphibians — that are consumed by wading birds. Photo: Atkins
The best indicators of project performance are those that can be evalu- ated and predicted through modeling, and then measured and moni- tored in the field, taking time before and after project development to verify the modeled response. Physical parameters (e.g., water flow, water stage, and residence time) will have a short-term response along with water quality parameters (e.g., dissolved oxygen, salinity, and nu- trients). Longer-term response can be expected for plants and animals (e.g., habitat, fish, and fisheries). With many restoration projects, there is a tendency to develop com- plicated performance measures when the best and easiest to use are developed using simple relationships that can be easily measured and followed with monitoring. An example is the simple relationship put forward early in the Everglades restoration process between the water level at gage P-33 in Shark River Slough and salinity in Florida Bay. There was an approximately one-month delay, but, when the water level at gage P-33 reached below a certain low point, salinity became hypersaline in Florida Bay. The hypersaline conditions resulted in sea- grass die-off in Florida Bay in 1988 and 1989, serving as the impetus for the Everglades restoration. Though improved modeling has produced additional, refined perfor- mance measures, the relationship between water level in the Everglades and salinity in Florida Bay is still used. The requirement for moving more freshwater into Florida Bay through Shark River Slough and/or Taylor Slough has been understood through modeling and monitor- ing for many years, but restoration of the system has been inadequate, while seagrass die-off occurred again in Florida Bay in 2016.
Implementation Many of the large restoration projects are still in planning or in the infancy of development. The adaptive management process is well un- derstood and should be implemented as it is intended to move projects forward despite lingering uncertainties. Projects should be planned and constructed with robust methods designed to adjust the program as it evolves with modeling and monitoring, along with well-developed performance measures to help define success and identify realistic outcomes. Once properly implemented, adaptive management will prove to be a valuable tool to verify when restoration goals are being met or adjust plans when problems are discovered or predicted.
DON DEIS, CEP , a principal scientist with Atkins (www.atkinsglobal.com), has 41 years of experience in environmental science. His expertise includes coastal monitoring, estuarine and marine ecosystems restoration, oil and gas explora- tion impacts, and natural resource damage assessment related to disasters.
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february 2018
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