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A mangrove creek restoration plan utilizing hydraulic modeling
Citation:
Marois, D. AND W. Mitsch. A mangrove creek restoration plan utilizing hydraulic modeling. ECOLOGICAL ENGINEERING. Elsevier Science Ltd, New York, NY, 108:537-546, (2017).
Impact/Purpose:
Mangrove forests are valuable ecosystems due to the services they provide to their surrounding communities. Some of these services include potential storm protection, habitat provision, and recreation. Despite these services, mangroves continue to be deteriorated and destroyed around the world as a result of anthropogenic activities. This study investigates the impact of urbanization on a mangrove creek in Naples Bay and proposes a restoration plan. Results indicated the system has experienced alterations to the patterns and amount of water that flows into it, both crucial components of mangroves. We then propose a restoration plan for this mangrove forest focused on widening and extending the existing creek that runs through it. We demonstrate how simple hydraulic models can be used to test restoration scenarios in order to increase the certainty of success in achieving restoration goals. Time and money can be saved if the correct baseline data is gathered and models are effectively used in the design and planning phases of the restoration. Suggestions of additional types of models that could be used in restoration planning are also discussed.
Description:
Despite the valuable ecosystem services provided by mangrove ecosystems they remain threatened around the globe. As a result, the restoration of mangrove forests has become an important topic of research. Urban development has been a primary cause for mangrove destruction and deterioration in Florida for the last several decades. Altering the hydrology of a mangrove ecosystem can have severe consequences for its ecological function and resilience to common coastal disturbances. Mangroves rely on tides to carry nutrients into the system and flush toxins out. They also need freshwater inflows from inland to prevent the occurrence of high salinities in the soil and water. Using field sampling and remote-sensing we assessed the past and present hydrologic conditions of a mangrove creek and its connected mangrove forest and brackish marsh systems located on the coast of Naples Bay in southwest Florida. By analyzing these data, we concluded the hydrology of these connected systems had been significantly altered from its natural state due to urban development. We then proposed a mangrove creek restoration plan that would extend the existing creek channel 1.1 km inland through the adjacent mangrove forest and up to the inland marsh area, and tested the hydrologic implications using the Hydrologic Engineering Center’s River Analysis System. We calibrated a hydraulic model of the mangrove creek using tidal data from Naples Bay and water levels measured within the creek. The calibrated model was then used to simulate the resulting hydrology of our proposed restoration plan. Simulation results showed that the proposed creek extension would restore a twice-daily flooding regime to a majority of the adjacent mangrove forest, and that there would still be minimal tidal influence on the brackish marsh area, keeping its salinity at an acceptable level. This study demonstrates the utility of combining field data and hydraulic modeling to aid in the design of mangrove restoration plans.
