by Joe Marchionno
The American Oystercatcher is a species of high conservation concern in Florida and has met the criteria for state-listing. The Cedar Key region of Florida provides excellent wintering habitat for oystercatchers, which rely on offshore oyster reefs for high tide roosts and inshore reefs for foraging on oysters and other invertebrates. Roughly 10% (1,100 birds) of the global population winters in Cedar Key, which is the largest concentration of wintering birds in Florida and 2nd largest across the range of the species.
Although the Cedar Key region shows excellent promise as a long term conservation area for oystercatchers, the extent of oyster reefs in the area has declined by over 80% in the past 30 years. As such, the objective our current study was to assess the benefits to oystercatchers of offshore reef restoration, which our prior research has shown to be the limiting factor for oystercatchers in this critical wintering ground. The prospects for restoring these oyster reefs are good with locally adapted and tested methods, a history of successful permit applications, and strong interest from state and federal agencies and local aquaculture farmers. This process is likely to increase long term stability and resilience of the roost sites because it uses living reefs that can outpace sea level rise and withstand extreme marine weather events. The overall objective of this project is to increase the amount of quality high tide roost habitat available for the American Oystercatcher, which will help to increase overwinter survival of the species.
We worked with a Coastal Engineer from DEP and Peter Frederick (UF, Department of Wildlife Ecology and Conservation) to design a structure that would buffer wave energy, encourage accretion and promote oyster settlement. The enhancement of two offshore oyster reefs used by oystercatchers as high tide roosting locations began in May 2016. Construction efforts, led and managed by FWC, have been facilitated by the University of Florida’s IFAS agent Leslie Sturmer and the Cedar Key Aquaculture Association.
Construction materials include clam bags filled with substrate and live oyster larvae that have been placed as a barrier revetment to buffer wind driven wave energy. Limestone rock will be placed behind the revetment, where accretion is already taking place, to function as a larger hard-structure for oysters to attach and grow.
Since construction began, deployed materials and their implemented designs have successfully withstood several storms including Hurricane Hermine. The ability for this design to show resistance to extreme physical conditions as well as oyster settlement halfway through its construction is a good indicator that oystercatcher roosting habitat will be improved through the use of this project’s restoration methods. Once construction is complete, long-term monitoring will continue so FWC scientists can collect necessary data to inform future oyster restoration designs to benefit birds and to track demographic information about the American Oystercatcher.