This article addresses current environmental issues by taking a network perspective to examine the initiatives to solve them. Previous investigations of network dynamics and mobilization concern the business context, but we broaden the analysis to the societal networks wherein business is embedded. Our aim is to investigate the early emergence of collective action around a common issue. We analyze the network mobilizers, who promote the issue and its solutions, and the mobilization mechanisms that they employ. We have conducted a case study that examines three initiatives to save the Baltic Sea, all involving business, governmental, and civil society actors. This rich case material leads us to formulate a conceptual model of value-based network mobilization. The mobilizing actors, values, and relationship sediments emerge as important factors in creating issue networks. Our key contribution is to show how the environmental (and societal) issues bring new types of actors to networks and change the rules of the game. We propose that 'modern environmental networkers' should become more important in the future, and that business firms need to develop their skills in playing the new games with these new actors.