Habitat Value of Man-Made Coastal Marshes in Florida

Mitigation in the form of habitat creation or restoration is often employed to minimize the losses of wetlands and wetland resources resulting from development and other human activity. Most projects in coastal areas of northern and central Florida have involved in the creation of wetlands dominated by smooth cordgrass (Spartina alterniflora) and black needlerush (Juncus roemerianus). Procedures for creating salt marshes were developed as a means to stabilize dredged material and eroding shorelines. The first projects were completed in the early 1970's, but only during the past 5 to 7 years have man- made wetlands been extensively used to mitigate for losses of natural wetlands. Although wetland creation is a relatively new technology, it has been clearly demonstrated that many types of wetland vegetation can be established on areas that were formerly uplands. Despite technological developments in wetland creation, there are still questions as to whether man-made wetlands are ecologically equivalent to naturally occurring wetlands. Twenty-two man-made coastal marshes of various ages were studied to determine their similarity to natural marshes. The majority of the sites were dominated Spartina alterniflora. Sites were located throughout northern and central Florida and ranged in age from approximately 1 to 10 years. The focus of the study was on the fish and wildlife habitat value provided by created wetlands. Vegetation characteristics were highly variable, but sites that were properly planned, constructed, and maintained served as viable habitat for animals normally associated with coastal marsh systems. Factors influencing site use by various animal groups and suggestions for future mitigation efforts are discussed.