Tsai, M.-F; Phuah, T.; Château, P.-A., and Chang, Y.-C., 2024. A system dynamics model for evaluating circular economy strategies of marine debris mitigation. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 105-109. Charlotte (North Carolina), ISSN 0749-0208.

The issue of marine debris, particularly plastics, has been receiving more attention globally due to mass production and improper disposal without careful management. This traditional linear economy, which adopted a “take-make-dispose” way of using plastic products, negatively affects the coastal environment. To combat this, a new concept of circular economy has emerged, which focuses on reusing waste as raw material for new products. In this regard, a circular economy strategy has been proposed to manage marine debris by reusing plastic wastes in the marine and coastal environment, thus reducing them. This study aimed to develop a system dynamics (SD) model to simulate the circular economy of Taiwan's marine plastic debris recycling process. The SD model was integrated with the Monte Carlo simulation and the decision tree analysis to identify important policies to develop a circular economy. The result indicates that the authorities should enhance people's environmental consciousness, restrict plastics production, improve waste management efficiency, and encourage green product design. Implementing these combined policies can decrease marine debris and generate profit for stakeholders. In the long term, the vision of a circular economy for dealing with the problem of marine plastic debris can be fulfilled.