In recent years, particular attention has been paid to fishing activities, and more specifically to aquaculture, a production process whose environmental impact at present is not being adequately submitted to any sort of serious assessment and control. The impact of aquaculture on the environment has nonetheless become an important issue for both potential customers and public opinion. The purpose of this study is to appraise environmental protection costs if and when a certified program of environmental management is put into effect in an attempt to change the present situation in which firms only comply with minimum environmental standards. A survey was conducted of all relevant information regarding production, organization, and budgetary aspects at the two firms participating in the study, I.e. an intensive fish farm, and a mussel far. An environmental accounting methodology was applied to the analysis of the data obtained from the survey. Through the representation of qualitative and quantitative data assessing the impact of production processes on the environment, the study attempts to propose an economically viable and financially sustainable environmental planning program for safeguarding both enterprise and environment.