Posidonia oceanica is an endemic seagrass species in the Mediterranean Sea. It has a key ecological role and many impacts on its ecosystem. Its role in fisheries production and in sediment stabilization are well-known. In fact, seagrass meadows provide habitats for a number of threatened species. However, throughout the Mediterranean these meadows are declining at a worrying rate, due to human activities. Factors such as destructive fishing practices, boat anchorages, bad water quality and climate change can destroy seagrass meadows.
Moreover, seagrass meadows in a large part of Greece have not been accurately mapped and hence cannot be adequately protected. This is why it is important to map P.oceanica more efficiently in order to be able to manage these threats. If we can precisely determine the location of the seagrass meadows, we will be able to put some management practices into action (for example, in relation to anchoring practices by recreation yachts, or the impacts of intensive aquaculture).
The goal of this project is to map P.oceanica around Lipsi Island in the Northern Dodecanese, Greece. The method involves using a drone (KARMA drone from GoPro) and taking pictures of the sea-bed from an average height of 200 meters. All the pictures are then analyzed in order to find potential seagrass patches.
Using a drone to map seagrass meadows is preferred over using satellite images as the drone can produce higher resolution images. This project will improve the understanding of P. oceanica meadow coverage on Lipsi. The data collected will be combined with other mapping methods being carried out in parallel, such as sonar and underwater transects, providing a lot of key information concerning the localization of P. oceanica.
Baptiste Villemagne
MSc in Engineering, ENSAT, France
