Posidonia seagrass is a crucial ecosystem within the Mediterranean Sea, playing a vital role in the health of the marine environment. Historically, and continuing today, its protection is intrinsically linked to the broader conservation efforts for Greek and Mediterranean waters. These underwater meadows are considered a key indicator of seawater quality and contribute significantly to biodiversity. Protecting Posidonia is therefore essential for maintaining a thriving marine ecosystem. Increased attention is now focused on safeguarding this often-unseen, yet critical, “protagonist” of the Mediterranean. New initiatives signal a renewed commitment to its preservation and the health of the sea it supports.