A growing increase in the world’s population and a gradual decline in poverty necessitate a search for new sources of protein in order to guarantee food security. Aquaculture has been identified as a potential sector capable of meeting the requirements for increased protein production without making excessive demands on the ecosystem. Although water makes up 70% of the earth’s surface, aquaculture cannot feasibly be practised everywhere; it requires a unique set of natural, social and economic resources to be managed in an environmentally responsible way. Finding suitable sites for aquaculture is becoming an ever increasing problem in the development of the sector as precautions need to be taken in setting up sites to ensure appropriate environmental characteristics exist and that good water quality can be maintained. Additionally, the effects of aquaculture on coastal and inland resources must be clearly determined to implement policies and regulatory frameworks to control its impact. Marine cage farming is gaining momentum, specifically in the Mediterranean and Black Sea coastal regions. For these sites to be further developed there is a need to minimize the effects on the environment and conflicts with other coastal users. To this aim the concept of allocated zones for aquaculture (AZA) is being adopted to provide specific areas for marine aquaculture to avoid environmental degradation. When choosing an (AZA) suitable site, it is vital to calculate ‘carrying capacity’ to reduce the risks and to protect the marine ecosystems. In this study the MERAMOD model was used to investigate the carrying capacity of marine fish farms. Modelling offers the possibility to simulate and predict the environmental impact of fish farms.