United Nations Convention on the Law of the Sea was adopted at the third convention on the Law of the Sea by the United Nations in 1982, and it introduced the Economic Zone as a new specific legal regime. It is indisputable that every coastal state has the right to declare its economic zone, both under the Convention on the Law of the Sea and on the basis of the customary international law of the sea. Yet, the Mediterranean states were reluctant to proclaim their economic belts, as the European Union (EU), under the influence of developed coastal member states, considered that the Mediterranean, as a closed or semi-detached sea, was not suitable for proclaiming such belts. Such a point of view was not based on the Convention. nevertheless, the deteriorating conditions of the fish stock and the dangers to the marine environment have affected the slow change in such an attitude. It was eventually realized that the expansion of jurisdiction in the Mediterranean was necessary in order to overcome the mentioned problems. In the desire to manage more successfully its living wealth of the Adriatic and to and protect the marine environment, Croatia had finally, on 3 October, 2003, declared its Protected Ecological and Fishing Zone (ZERP), which contains all the essential elements of an economic belt. Italy, Slovenia and the EU institutions reacted to Croatia´s unilateral proclamation and demanded that the country postponed the application of the ZERP regime until an agreement is reached in the interests of all neighbouring countries. Under the influence of such pressures, the Decision on the extension of jurisdiction of the Republic of Croatia in the Adriatic Sea has been altered several times. The final decision, which was passed by the Croatian Parliament in March 2008, stated that ZERP would not be applied to EU members.