Posidonia oceanica is a seagrass species found in the Mediterranean Sea. It plays a crucial role in marine ecosystems by providing habitat and food for various marine organisms. This plant can grow in dense underwater meadows, which help stabilize the seabed and reduce coastal erosion. The leaves of Posidonia oceanica can reach lengths of up to one meter and are important for oxygen production. Additionally, these seagrass meadows act as carbon sinks, helping to mitigate climate change by absorbing carbon dioxide from the atmosphere. Their conservation is vital for maintaining biodiversity and healthy marine environments.