EditorialComment on “Protecting the Florida Everglades wetlands with wetlands: Can stormwater phosphorus be reduced to oligotrophic conditions?” by W. Mitsch et al.

Mitsch et al. (2015) recently examined the results of a three-year mesocosm study that investigated several wetland vegetation options for enhancing phosphorus (P) removal performance of existing Stormwater Treatment Areas (STA's) for Everglades restoration. Here, we comment on that article and provide additional context to those results. Specifically, (1) similar transient demonstrations of ultra-low discharge P concentrations (≤12 μg/l) in past STA mesocosm and full-scale systems have not been reliable indicators of long-term performance, (2) P removal rates are always much lower in “back-end” of wetland systems, such as those investigated by Mitsch, than front-end or STA-average rates, and (3) there already exist numerous full and field-scale back-end STA systems that outperform these mesocosm results and have been doing so for years. For these reasons, we recommend caution in interpreting their results.