Bizerta lagoon is an important socio-economic pole in northern Tunisia. Its shores and maritime space host lots of human activities, such as coastal fishing, shellfish farming, maritime traffic, military activity, recreational fishing and nautical sports. These activities cause severe pollution and they result in many anthropogenic disturbances. Naturally, conflicts of interest between the different operators have always existed. However, recently these disagreements, particularly between coastal fishermen and shellfish farmers have degenerated into an act of vandalism in November 2019. Fishermen destroyed all the bivalve farms facilities and productions. This act is the result of the build-up of several factors, notably the spatial interaction between the two activities and the improper practices of the shellfish farmers, which are according to fishermen "the major source of the lagoon pollution". Despite the fact that the Tunisian government has made considerable efforts to solve this issue, mitigate this conflict, and restore shellfish farming activity in the lagoon, this event has had major socio-economical, geo-political, environmental, and technological impacts. Within this framework, the current paper aims to suggest a management plan that should improve the lagoon status and attain the desired sustainable development of all activities. Turning to Marine Spatial Planning (MSP), we propose an Allocated Zone for Aquaculture (AZA), effective governance of the lagoon and fostering of Sustainable Blue Growth (SBG). These proposals are in line with the Tunisian strategies in terms of aquaculture sustainable development, establishment of MSP along the entire Tunisian coastline and the promotion of blue economy. They also meet several sustainable blue development objectives of the United Nations.