Clam Creek Marsh Monitoring - 9/9

Clam Creek – Marsh Monitoring 9/9/2011 By Kari Tracy
On September 9, 2011 our conservation class took a trip to the Clam Creek marsh on Jekyll Island to assist in monitoring an on-going project sponsored by the Georgia DNR (Department of Natural Resources) and the Glynn County Engineers.

So you may be wondering, what is the big deal? Why should we spend our money and time to protect these marshes? Besides the natural enjoyment humans receive from the beauty of the marshes, referred to as biophilia, these coastal marshes provide its local residents with many direct and indirect values. For instance, did you know that 70 percent of the recreationally and commercially important fishes, crustaceans, and shellfish spend part of their lives in the estuary that these marshes inhabit? Also, the marshes create a place for ecotourism. This means money coming into the surrounding communities. Although direct values (the money that comes from them) such as these are nice, sometimes it is the indirect values that we benefit most from. Just a few of the indirect values that the salt-marshes offer are: mosquito control, inland protection from weather forces (such as hurricanes), and even water and air quality control (marshes naturally assimilate nitrogen and pollutants).
The area that our class is working on with Georgia DNR and the Glynn County Engineers is on Jekyll Island where a bike path was constructed through the marsh. As a result, the bike path cuts off the marsh and creates a pocket marsh. In order to allow water to flow from one side of the marsh to the other, large pipes were laid in the bike path foundation. Unfortunately, these pipes have proven to be inefficient for several reasons. The first reason being, they are placed too high and the water is not able to flow through easily. Another reason it did not restore the hydrology is because even when the water level is high enough to flow through, the opening of the pipe is not large enough for the amount of water needed to fill the pocket marsh. This interruption of water flow into the pocket marsh caused a major die-back in many of the natural marsh plant species such as: Black Needle Rush (Juncus roemerianus), Saltgrass (Distichlis spicata), and Salt Marsh Cordgrass or Smooth Cordgrass (Spartina alterniflora). Less salt-tolerant species were able to become more prevalent in the area. Additionally, the water in the area was no longer moving due to tidal influence, causing an increase in the mosquito populations growing in the area.
In an attempt to restore the water flow from the marsh to the pocket marsh created by the construction of the bike path, the Glynn County Engineers removed the inefficient pipe and replaced it with an open bridge in hopes of restoring the dying marsh. The open bridge would allow the water to flow freely to the other side and the salt marsh plants and fauna would expectantly be restored. To track the progress of the marsh restoration, it is necessary to designate certain points or areas to consistently monitor. This is what our class partook in: monitoring of the progress after the installation of the bridge.
On September 9th, 2011 our Conservation Biology class completed transects for the pre-designated points in the marsh. We counted the number of live Juncus and Distichlis stems, and also the number of live and dead Spartina stems. Then we recorded the percent cover of each species (including browning and dead species of other plants other than Spartina). Next, we measured and listed the height of the five tallest Spartina plants and noted the color of the plants in the plot. After all the plant species counts were completed, we counted the number of live and dead periwinkle snails and mussels. We estimated crab abundance by counting the number of crab holes larger than five millimeters (about the size of a pencil eraser). We also tried to acquire an accurate reading of the salinity of the water per each sampling point. The salinity was taken using a refractometer. A few drops of water collected from a freshly made hole was placed in the refractometer and the salinity then observed. We found that in many places, water did not fill the holes we created. This means that the area did not have recent water flow. The water that was tested from a few of the areas implied that the water had a very high salinity. It was suggested that the drought could be causing a higher than normal salinity. This could affect the vitality of the plant species and also the fauna in the marsh. Many of the pine trees were already losing their pine needles—which could be a possible result of the increased salinity.
Overall I enjoyed myself and so did most of everyone else. The weather was nice for being outside and there were almost no bugs (an uncommon event in the South). It was a great learning experience and we made great connections!

Clam Creek Wetland MonitoringBy Shawn Flanagan Jekyll Island is a barrier island located in southeast Georgia. In the 1880’s, Jekyll Island was home of the Jekyll Island Club, which was a getaway for many aristocratic families such as the Rockefellers, Vanderbilts, Morgans, and Pulitzers. They came to get away from the hustle and bustle of the city and enjoy the peace and tranquility that Jekyll Island offers. Thousands of people still travel here every year in order to enjoy its rich history along with its natural beauty. Jekyll Island is home to an extremely complex and delicate tidal marsh ecosystem. The marsh ecosystem is home to several unique species of fauna and vegetation. Our service-learning project for the semester was to monitor a wetland site in the Clam Creek picnic area, on Jekyll Island.

The site that we surveyed was along the clam creek bike path. Initially, when the bike path was built, a 6 inch in diameter drainage pipe was put into a concrete walkway to allow tidal flow to reach behind the path. Unfortunately the volume of tidal flow was unknown and the 6 inch pipe was too small to allow adequate passage of water. Inadequate water flow to the marshland behind the path caused a change in the pH and salinity within this section of the marsh. This change created a freshwater mosquito breeding ground and altered the flora and fauna in this section of the marsh. A large amount of dieback was observed after the installation of the path. In an attempt to restore this section of marsh, Georgia DNR, along with engineers from the Glynn County Engineering Department, removed the section of path with the drainage pipe and installed a foot bridge. This bridge allows much more tidal flow to enter the marsh, which in theory would restore the area to its previous pH and salinity, eliminating the large amount of mosquitos restoring the flora and fauna. DNR tasked us to record data from this site as a service-learning project.
The area along the clam creek bike path was broken into five transects with varying quadrants in each transect. We used a tool (four pieces of half inch PVC pipe strung together in a square) that measured an area 1 m² and oriented it north in order to create the quadrant itself. We used the same protocol that was previously used by various groups for the marsh-dieback analysis. We recorded specific flora and fauna within the quadrant. The flora that we were specifically looking for in each quadrant were; Spartina, Distichlis, and Juncus. We recorded the approximate percent that each species covered within the quadrant. We paid very close attention the Spartina, because it is a keystone species within the marsh ecosystem. The fauna that we were looking for in each quadrant were; periwinkle snails, holes indicating the presence of fiddler and mud crabs, and mussels. Any other fauna was also recorded. After the vegetation and fauna was recorded, we used a PVC pipe to create a small hole next to the quadrant for water to collect. A small sample of this water was collected and placed on the lens of a refractometer in order to determine the salinity and specific gravity. Finally, we took a photograph of the quadrant so that it could be saved for reference. We repeated these steps for each individual quadrant.

View Clam Creek Site in a larger map
The first time that we surveyed this location, we learned about the protocol and recorded data for three locations on the southwest side of the bridge. This service-learning project is not only important, but also very applicable to what we are learning about conservation ecology. This particular part of Jekyll Island is enjoyed by many people for its scenic view and the opportunity it gives people to interact with nature. This not only gives people a better sense of overall well-being, it also helps drive the economy because people come to Jekyll Island and spend money. The issue then becomes how to allow the area to be viewed and enjoyed, while also preserving its natural state. In conservation ecology, we study how to accomplish this, whether it is through green practices or nature-friendly ecotourism. In this particular case, it is yet to be seen if the addition of the foot bridge will restore the quality of the marsh. Unfortunately, the weather did not cooperate this last wet season, so the marsh did not get as much as a tidal influx as DNR and the engineers were hoping for. Only time will tell if the restoration effort is a complete success.