Project
Why Economic Valuation?
These wetlands are worth having a conversation about; converting their value into dollars aids in that conversation.
An economic valuation will provide policy-makers with the proper tools and a common metric to compare and discuss the importance of protecting the integrity of wetlands alongside other important land-use issues in a way that resonates with broader societal understanding.
This will facilitate communicating the importance of these wetlands as factors such as sea leve rise and development encroach on the buffers and wetlands themselves. These monetary values will also help provide context for considering costs associated with devleopment that impacts the quality of the wetlands as well as the ability of upland migration of the wetlands.
Why Southern California Coastal Wetlands?
Southern California coastal wetlands, stretching from Point Conception to Tijuana, provide a variety of services, ranging from recreational enjoyment to significant flood protection. Diverse habitats attract natural biodiversity and tourism alike, while also providing services that help mitigate and adapt to climate change, a growing concern everywhere along coastal California.
However, these wetlands have also been some of the most negatively affected by development, losing 48% of of habitats since the mid-19th century.
Objective
Determine and quantify the key ecosystem services of these coastal wetlands to communicate the value of these wetlands and help inform policy.
Questions
1. What are the ecosystem services that are most relevant in the Southern California coastal region?
2. Which coastal wetland habitats provide which ecosystem services?
3. How much are the wetlands worth in dollars today?
Approach
This project employed a “bottom-up” approach to conduct the valuation of Southern California’s coastal wetland habitats. The methods used in this project quantified the value of individual ecosystem services provided in the selected coastal wetland habitats. The values determined for each ecosystem service could then be grouped into habitats, which in turn could be grouped into whole wetlands. Due to the nonmarket nature of many of these ecosystem services, three different valuation methods were used in determining economic monetary values.
Ecosystem Service Rate Valuation
This method used annual flow rates for the identified key ecosystem services provided by Southern California’s coastal wetland habitats. Flow rates were taken from existing studies that had been conducted in habitats similar to Southern California. A commonly accepted dollar value of the ecosystem services was then applied to the flow rates to determine the overall gross monetary benefit.
Benefit Transfer
This method used values from existing literature of study areas that were similar in ecosystem services, climate and demographics and applied these gross values to the study site. In the literature, market and non-market, use and non-use values of ecosystem services were primarily valued using avoided cost, replacement cost and hedonic pricing methods.
Contingent Valuation Survey
In contrast to the other two methods, the survey captured values or avoiding degradation. Rathern than determining the value of individual ecosystem services, they survey provided values for the wetland areas as a whole.Using a hypothetical increase in income tax, we asked California residents what they were willing to pay to avoid degradation of Southern California coastal wetlands. These results provided an upper and lower bound on respondents’ willingness to pay, as well as an average annual stated value.
