The industrial symbiosis in eco-industrial parks requires intense broker involvement to be implemented. However, market changes and technological advancement could undermine the level of symbiosis during operations. In this research, the existing symbiosis indicators were identified and classified using a systematic literature review. The results demonstrated the necessity to achieve indicators sufficiently simple that brokers are enabled in confronting the monitoring and promotion of symbiosis. In this paper, an industrial symbiosis indicator is introduced that detects the variation of symbiosis over time and that provides a dynamic perspective of the eco-industrial parks. This indicator can be used in the underpinning of decisions and the provision of continuous improvement. It was evaluated in several theoretical scenarios created from real data. The three scenarios are: absence of symbiosis, presence of symbiosis, and perfect symbiosis. The results demonstrate consistency between the values of the indicator and changes in the scenarios. The industrial symbiosis indicator proposed was able to detect variations in symbiosis with simple measures, and could support managers in encouraging companies to actively engage in effort for more advanced levels of symbiosis. The concept of “environment impact momentum”, proposed and applied in this research, is a theoretical construct that could support a new class of indicators capable of identifying the dynamic behavior of eco-industrial parks.