Understanding the Monetary Value of Water Quality Through Ecosystem Service Valuation

Aquatic ecosystems are increasingly threatened by human activities and climate change, leading to a loss of values in the form of the services they provide to both nature and society. These lost values are still not well understood, and the methods to carry out their assessment are very diverse. The objective of this study is to compile and synthesize the different methodologies employed by the academic community to economically value water quality in the context of ecosystem services (ESs). To this end, a systematic literature review is performed, using the SCOPUS database, expert-based review tools, and content analysis and synthesis. Results show that most studies on the subject come from the northern hemisphere and tend to value water quality using Regulating & maintenance ESs (notably bioremediation and freshwater chemical regulation) and cultural ESs (notably active recreation) as proxies. Most studies perform primary valuation studies, with stated preference methods being the most frequent; unit value transfer is also commonly seen. These findings suggest that there is a lack of understanding regarding the value of water quality in southern hemisphere nations, and point at a possible over-reliance on practical but potentially biased valuation methodologies.