In this paper we used a net present value model to jointly estimate the willingness to pay (WTP), and the intertemporal discount rate, for a biodiversity environmental conservation program whose payments are allocated along a time horizon. We applied a contingent valuation survey to capture the economic value associated with the protection of a marine ecosystem in the marine reserve, Choros-Damas in Chile. Respondents faced a scenario with a WTP question with periods of 1, 5, and 10 years.