The economie performance of shrimp rearing is govemed by three types of factors a) the environmental conditions prevailing around the farms, b) farmers' zootechnical practise and know how, c) economie management. The Gambas project aims at identifying the relative role played by these parameters in the success or failure of small-scale shrimp farming enterprises of the Mekong delta in Vietnam. It is being conducted by French and Vietnamese partners under the co-leadership of Ifremer and the Nha Trang Institute of Oceanography.