The islands are a marine reserve, and the proximity of the River Ter and the currents in the area creates an environment conducive to marine life. The explosion of life is incredible and difficult to see in the Mediterranean. The massive groupers are the protagonist of the islands. They are everywhere, and some are intimidating in size. The walls of gorgonians adorn almost all dive sites with their colours, but perhaps, the jewel in the crown in Medes is the encounter with a sunfish (Mola Mola), frequent at certain times of the year.