By: Avah Avonda

Hello again, my name is Avah and I am a research intern at the GTM Research Reserve in northeastern Florida. Oysters are a staple in research here at GTM, and for good reason. Not only are they a common, delicious dish of the restaurants in our area and a paddle boarder’s fear, oysters also play a key role in the estuarine ecosystem. These shellfish filter unwanted excess nutrients from our waterways, protect water quality, and prevent algal blooms. Oysters are the anchor of an estuary. Thus, annual oyster monitoring is held at GTM and investigators from different institutions are welcomed to pursue oyster research. These go forward to aid water quality, sustainability, and other developments.   

Are there quicker ways to identify an oyster reef? Can drones help us monitor reefs that are on mudflats inaccessible by boat? How is a reef impacted by harvesting? What about boat wakes? Meet Alyah Bennett: a masters student at the University of North Florida and the mastermind behind Drone the Oyster. Bennett, research staff, and volunteers (including myself) made our way to different reefs around northeast Florida to assess these questions. These include reefs just outside the intracoastal waterway in Marineland, Salt Run, and Devil’s Elbow. These are consciously chosen to include harvested and non-harvested oyster reefs as well as oyster reefs that are impacted by boat wakes and those that aren’t. 

Once we arrive at the reef, we need data. In randomly placed quadrats with a grid system, we find percent cover of live oysters, box oysters, shells, and mud. This is to see the representation of these different components on the reef. Eventually, these percent covers are compared with other reefs to find if wake and harvesting are potential deteriorating factors to a reef’s health. I learned that a box oyster is recently dead. It still has shells on its hinge, but it is slightly open and resembles a box as shown in figure 2. You know an oyster is alive when it is closed and especially slightly pressed, little bubbles come out of the edges of the oyster where the shells meet. Pretty handy information, right! 

Then, we take the most southern corner and collect a sample of the oysters, mussels, clams, and whatever else we find until we hit dark mud. The depth of the sample is tracked – how deep or shallow the sample is dictates the health and age of a reef. Rugosity chains are also used to measure surface roughness on a small scale; the variance in height and crevices in a reef. This is a common measurement for reef health – the more surface roughness, the better habitat for other creatures. Next, stewardship experts Savanna Mathis and Allix North take elevation readings and place digital markers at every quadrat location. Finally, it is time for the drone!

North directs a drone to take two dimensional and three dimensional maps of the reef at solar noon and low tide to ensure the drone captures the whole reef. With these images, Bennett can predict if a drone is a viable measure for reef condition. If the results of Drone the Oyster turn in favor of drones, imagine how much easier it would be for oyster farmers, researchers, and boaters!

In the lab, Bennett, staff, and volunteers measure various species in the sample that was collected in the field. We separate the live oysters and organisms from a collection of shells and mud, then measure from there. Measurements of mussels, clams, and live oysters are compared between sites to assess the potential effects of harvesting and boat wakes on the health of a reef and to see if it correlates with other measurements of vitality. 

Oysters are important to all walks of life. Filtering our waterways and providing livelihoods for many, these shellfish need protection and sustainability. Bennett seeks to find an easier monitoring strategy to contribute to these goals. Once we know these answers, we can take action to keep our oysters alive and well for ourselves and for future generations. Learn more about the project collaborative at https://nerrssciencecollaborative.org/project/Kingsley-Smith22

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