Last year, we installed several habitat enhancement measures around the seawall at the UF/IFAS Nature Coast Biological Station. Among other things, we increased the habitat complexity in front of the seawall. We did this by adding limerock boulders and a row of oyster recruitment domes (commonly called “reef balls”). For more details, see this post.
So, one year later, how is the project doing? Are the reef balls recruiting oysters and serving as habitat?
Monitoring project success
In any restoration or enhancement project, monitoring is key. Monitoring is the collection of data on variables related to project goals. Without monitoring data, you would not be able to assess whether or not the project is successful. In the case of the reef ball project, our goal was to increase the area available for oysters to recruit. We had the secondary goal of reducing wave energy along the shoreline.
To monitor the success of our primary goal, we measured the percent cover of organisms encrusting the surface of the reef balls over time. Each quarter, we measured percent cover in the interior and exterior surfaces of a subset of the reef balls. We tracked total percent cover as well as percent cover of specific groups, mainly oysters and barnacles.
Year 1 results
Since Sept 2018, reef balls have become mostly covered with living organisms. Oysters or barnacles are covering approximately 95% of the surfaces. Interestingly, reef balls were dominated initially by barnacles (dotted lines in charts). Later on, oysters began to take over and dominate the community (dashed lines in charts). Ecologists call this type of community change over time succession. Successional patterns are influenced by things like competitive relationships, differences in larval supply, and predation.
We are seeing other interesting patterns, too! For example, the interior and exterior surfaces of the reef balls differ slightly in their successional pattern. It seems that oysters began to increase in abundance slightly sooner on the interior surfaces of the reef balls. There also appear to be some slight differences among the different sizes of reef balls. These difference could be related to elevation (position in the water column) because tolerances for different levels of air exposure could influence survival.
Overall, the project is showing promising results in year 1. Stay tuned for more project updates!