The core of this paper is an evaluation of the willingness to pay for non-use values of the ecosystem services related to the Banc d’Arguin National Park in Mauritania. This coastal protected area, the largest in Africa, has existed for more than forty years and plays a major role in the conservation of biodiversity. We use contingent valuation to estimate the willingness to pay by Mauritanian populations for the protection of biodiversity in the park. Results show that the non-use value accounts for 12–29% of the total economic value attributed to the park’s ecosystem services. Interestingly, a correlation exists between the familiarity with the park and the living conditions of people interviewed and their willingness to pay: rural and distant populations have a lower willingness to pay than closer or urban population. The results also highlight that the protection of biodiversity is compatible with the maintenance of the Imraguen way of life since their fishing practices are based on traditional sustainable catch techniques.