The final paper talks about the Adriatic Sea, a part of the Mediterranean Sea located in between the Balkan and Italian Peninsula to the Strait of Otranto in the southeast, about the biodiversity of the Adriatic Sea and the protected areas of the Adriatic Sea in the surrounding countries. A special emphasis is placed on the noble pen shell, which is not only the largest Mediterranean bivalve and the largest endemic species of the Mediterranean Sea, but also the most famous Mediterranean bivalve. The stress is also put on its disappearance and the threats posed to it along with the course that led to its extinction. Having realized the seriousness of the situation, measures and different procedures are being carried out in order to protect the noble pen shell and its habitat both in the Adriatic Sea and in the surrounding seas where it has been spotted. Projects are being initiated about Pinna nobilis and the importance of its preservation so that as many people as possible are being involved and educated.