Abstract
The existence of a scientific concept : paralic ecosystem allows to understand how lagoonal environments work. As a consequence, it is certainly a resourceful matter for their management ; though elected officials have to be able to turn it to account. The problem therefore arises of its appropriation by the sphere of persons in charge. Communication however seems difficult between the scientific research domain and the fieldwork one. This difficulty could be explained by an insufficient adaptation of presentation of scientific knowledge to each one's conceptions and culture. Subject of didactic is the study of acquisition and conveying processes, so it gives theoritical references which could be a response to this difficulty. To test this hypothesis we suggest : - a presentation of the concept compatible with acquisition and development of knowledge processes, which one could facilitate its assimilation and application. This approach, inspired from a method of abstraction learning, consist in conveying the concept referring to its attributes, - a sample survey of the people's representatives of Languedoc-Roussillon region, in order to identify some of their conceptions and especially these "ideas" which could be obstacles for the comprehension of the paralic ecosystem model. If scientific knowledge continually advance, this presentation is a great asset to a dynamic communication whose useful knowledge remains an evolutionary part which is gettable for everybody. In this way, decision making about environment planning could be easier.