Dr. Grayson R. Morgan and his team conducted a study titled "The Dynamic Nature of Wrack: An Investigation into Wrack Movement and Impacts on Coastal Marshes Using sUAS". Wrack is essentially dead plant material that forms mats in these marshes. It’s a natural part of the ecosystem, but it can have significant impacts on the health and vitality of the marsh.
To study this, the team used something called small unoccupied aerial systems (sUAS), which are essentially drones. These drones were equipped with cameras that could capture detailed images of the marsh. They flew these drones over a specific type of salt marsh, dominated by a plant called Spartina alterniflora, for an entire year. This included the period during and after Hurricane Isaias, which hit the area in August 2020.
The drones were flown only during low tide, which is when the marsh is most exposed and the wrack is most visible. The drones captured images of the marsh, which were then used to identify and map the wrack. They used a system called Geographic Information System (GIS) to create a digital map of the wrack distribution.
Dr. Morgan and his team found that wrack mats, which had formed before and after the hurricane, stayed in the marsh for about three months. They also found that most of the wrack was closer to water bodies like rivers or streams. This makes sense because wrack is carried by water.
However, after the hurricane, they noticed that less wrack was found close to rivers or streams. This change in distribution was an interesting discovery and highlighted the impact of such storm events on the marsh ecosystem.
This study is a great example of how technology can be used to enhance our understanding of natural ecosystems. The use of drones allowed the team to monitor the marsh in a way that would have been difficult, if not impossible, with traditional methods.
Dr. Morgan reflected on the experience, saying: “This study suggests that the high spatial and adjustable temporal resolution advantages that sUASs provide are optimal for mapping and monitoring wrack location and visual impact over an extended period of time, especially before and after a hurricane event.”
Dr. Morgan's full study was published on August 19, 2023 by the Multidisciplinary Publishing Institute (MDPI) in the Journal "Drones". Access the article here.