The Delta of the Ebro river was declared a Natural Park in 1983 and it is one of the most important wetland areas in Spain. Currently, the tourism market has now begun to make inroads into this natural area, and consequently this type of activity can often lead to considerable strain on the environment. In this context, this present paper introduces the determination of carrying capacity as an appropriate tool to improve environmental management of the Delta tourist destination. In order to achieve this goal, the carrying capacity of the two busiest cycling paths is proposed from two perspectives: as a warning indicator to allow evaluation of whether or not the area is under stress beyond the desirable threshold and as an instrument of sustainable management of a protected area. The results show that it is precisely in spring and summer when it is most likely that the greatest pressure is imposed on the delta area, and consequently these results emphasize the necessity for careful planning of recreational activities. This paper also introduces the applicability of carrying capacity concept to tourism. Even when certain constraints are considered, the appropriateness of this concept as a beneficial tool in environmental and recreational management is confirmed.