Lagoons and their characteristic coastal bay-mouth bars represent 15 percent of the world coastal zone. They are among the most productive ecosystems in the biosphere, this productivity resulting from the interplay of ocean and continent. An International Symposium on Coastal Lagoons (ISCOL) was held to: assess the state of knowledge in the various fields of research on these lagoons; bring about consultation and collaboration between specialists in the developed and less developed countries; and establish interdisciplinary programs of joint research and training in an international regional framework which could uncover scientific bases for the development and management of coastal lagoons and their interfaces. ISCOL proceedings are presented in this three-part report: (1) introduction (includes background information); (2) objectives and organization of the symposium (includes highlights of sessions); and (3) recommendations. The latter include general recommendations and those related to: research; education and training through research; and development and management. A list of participants, the ISCOL program, and questions for a panel discussion on scientific aspects, exploitation, and management of lagoons are provided in the three appendices. (JN)