ABSTRACT
This chapter considers the role of ecosystems and ecosystem services related to freshwater. It outlines basic principles of economic valuation specific to hydrologic and aquatic ecosystem services. Freshwater aquatic services encompass the services provided by freshwater ecosystems themselves, such as provision of fish. Discussions of freshwater ecosystem services have generally focused on the many ways people use freshwater. Freshwater ecosystems, including lakes, streams, wetlands and estuaries, provide a range of services. Freshwater systems also provide regulating services, stemming from ecosystem processes such as in-stream nutrient processing, and cultural services, including those related to fishing. In much research as well as for management purposes, however, there is considerable interest in assessing the monetary value of freshwater services. Ecosystem services provide a compelling framework for management because they directly link the impacts of landscape actions to beneficiaries. People are increasingly interested in "green infrastructure" projects that deliver desired freshwater services alongside a variety of other ecosystem services.
