Valuation of Marine Ecosystem Threshold Effects : Application of Choice Experiments to Value Algal Bloom in the Black Sea Coast of Bulgaria

Abstract

Algal bloom arises in part from anthropogenic emissions of nutrients into the coastal zone. Increased interest in water quality in coastal and marine areas stemming from the Water Framework Directive and the Marine Strategy Framework Directive leads to important questions in terms of policies to address nutrient loadings. This paper presents the results from a choice experiment for the valuation of algal blooms in Varna Bay, Bulgaria. Varna Bay is an important tourist destination and a large port city on the Black Sea coast of Bulgaria. Algal bloom events have been experienced frequently in this area. A choice experiment questionnaire was developed to be applied in Varna Bay. The key attributes used were visibility, duration of bloom and the amount of congestion on the beach. The amount of bloom is found to be important - respondents are willing to pay for a program that entails 1 week of algal bloom about 33 Leva (s.e. 8.09) when there is high visibility; 21 Leva (s.e. 5.75) with medium visibility and 9 Leva (s.e. 3.48) with low visibility. Respondents are willing to pay more for programs that offer shorter duration of algal bloom. The marginal price for one metre of extra space between the respondent and the nearest person is equal to 0.38 Leva.threshold effects; marine ecosystem