Search

The Florida Everglades, the largest subtropical wetland in North America, is in the midst of one of the most comprehensive and expensive environmental restoration efforts in history. Over the past 150 years, the Everglades has suffered substantial degradation due to massive drainage projects, polluting agricultural practices, and urban population growth. Decades of scientific investigation have shown that phosphorus (P) pollution is a primary driver of this environmental decline. This paper reviews how and why specific P‐management goals and strategies have been adopted in support of Everglades restoration, focusing on the often‐contentious process for converting science into restoration policies and standards. We synthesize current P‐management successes, failures, and tradeoffs, including the challenge of balancing multiple hydrologic and water quality restoration goals with the priorities and values of a diverse group of stakeholders. We then highlight promising future directions for Everglades P policy and propose questions to help guide the discussion of future restoration priorities and research needs in this and other complex social–ecological systems. The overall goals of this review are thus twofold: (1) to support an in‐depth understanding of the past, present, and potential future of P management approaches in this globally unique social–ecological system; and (2) to provide a broader framework for understanding how the coevolution of science and policy can support or undermine large‐scale ecosystem restoration. [ABSTRACT FROM AUTHOR]

Eutrophication is a widespread global scale pollution problem. Agricultural areas are generally the main contributors to eutrophication, whereas sewage and industrial discharges, which usually receive some treatment prior to discharge, are a secondary source. This is mostly the case of the ultra-oligotrophic Florida Everglades, where natural water sources are often enriched by nutrients from large-scale industrial agricultural stormwater runoff. Remediation of these agricultural waters cannot be conducted with the usual environmental engineering solutions, and in this context ecological engineering approaches such as constructed wetlands are much more suitable. Moreover, these wetlands provide other ecosystem services such as carbon sequestration or habitat provisioning. In this paper we have implemented a mechanistic phosphorus model into a time-space-dependent mathematical simulation platform (COMSOL Multiphysics™) which has been calibrated with wetland mesocosm data. Subsequently we have evaluated different characteristics of constructed wetland physical elements such as internal walls and baffles, different types of inlets, parallel and series operation, and increase in hydraulic retention time (HRT) to study total phosphorus (TP) removal performance and to improve efficiency. Simulation results indicate that wetland mesocosm soils released dissolved organic phosphorus which was washed out together with the effluent, making very difficult to attain a concentration lower than a target of 10 μg TP L−1, as required to protect the Everglades. Simulations showed that the design based on combination of the bottom inlet together with parallel operation extensively improves efficiency. Target TP concentrations can be achieved with this design together with an increase on 25% of hydraulic retention time. With this study we demonstrate the usefulness of the model for detailed designs, opening the door for its use in field scale applications. Image 1 • Pollution caused by agricultural drainage waters is a worldwide problem. • Constructed wetlands are very suitable to prevent agricultural drainage pollution. • A complex model was developed to study phosphorus removal. • The model is very useful for detailed designs and field scale applications. [ABSTRACT FROM AUTHOR]