Wise use of wetlands, including the conservation and restoration of hydrological functions, is essential in maintaining an infrastructure that can help meet a wide range of policy objectives. In many cases, natural ecosystems can provide ecosystem services at a lower price than hard engineered approaches. For example, the benefits of mangroves in southern Thailand were estimated at about US$10,821/ha for coastal protection against storms, US$987/ha for fish nurseries and US$584/ha, in net present value terms for collected wood and non-timber forest products.
According to this estimate, most of the economic benefits associated to mangrove conservation were due to the role of the mangrove wetlands as a natural infrastructure against storms. In contrast, the benefits of commercial shrimp farming were estimated at US$ 9,632/ha, with government subsidies contributing the equivalent of US$8,412/ha . Hence shrimp production without subsidies over the period creates a benefit of only US$1,120/ha, which is dwarfed by the monetary value of the ecosystem services provided by mangrove conservation. While the benefits of mangroves are provided continuously, shrimp production declines after five years and shrimp farms are abandoned when turning unproductive. The costs of restoring mangroves are US$9,318/ha beyond the private profits from shrimp and have to be borne by the public.
Source: The Economics of Ecosystems and Biodiversity for Water and Wetlands. IEEP, London and Brussels; Ramsar Secretariat, Gland. 2013. –> See the full report