Economic Valuation of Mangrove-Fishery Linkages in Guyana and Suriname

Mangroves are among the most productive ecosystems in the word. By providing valuable ecosystem services, mangroves enhance human well-being and contribute to biodiversity conservation in the tropical and subtropical regions where they are found. Mangroves provide nursery, feeding, breeding grounds, and shelter areas for many marine species, which in turn enhances the productivity of traditional and commercial fisheries. The objective of the present study is to evaluate how mangrove ecosystems affect fisheries in Guyana and Suriname, as part of a collaborative project between the Nicholas Institute for Environmental Policy Solutions and Conservation International. The evaluation involved conducting a meta-analysis of information drawn from 21 mangrove-fishery linkage studies from around the world to estimate a general model relating fish catch to mangrove area. A benefit transfer method was then used to apply the results from the meta-analysis to recent and projected future changes in mangrove areas in Guyana and Suriname, and thereby predict the impacts on fish catch in the two countries. The first section of this report provides an overview of mangrove ecosystems, definitions of the four types of ecosystem services identified by the Millennium Ecosystem Assessment, and an outline of the ecosystem services provided exclusively by mangroves. This section also highlights some of the main global drivers of mangrove loss. Lastly, it provides the main objectives of this project, an overview of Guyana and Suriname, and estimates of the areas and trends in mangroves in both countries. Mangrove area change was calculated using the average of estimates from two sources for each country. The estimated changes in mangrove area during 2000-2017 were -1.96% per year in Guyana and -0.76% per year in Suriname. The second section of this report describes the methods used to determine how these trends have affected fisheries in Guyana and Suriname. After providing an overview of the meta-analysis and benefit transfer methods, this section explains the variables selected for the meta-analysis. Variables were selected to capture essential characteristics of the study sites and the studies themselves. Finally, the equation estimated by the meta-analysis is defined. This equation relates the impacts of mangrove area reported by the studies to the selected variables. Observations were included in the dataset for estimating this equation only if a study included sufficient information for calculating the reported impact as an elasticity, which can be explained as follows: denoting the elasticity by Ɛ, a 1% increase in mangrove area increases fish catch by Ɛ%. The third section of this report applies the results from the meta-analysis to calculate the benefit transfer estimates for each country. There are two final models: a shellfish model and a finfish model. The shellfish model was used to generate the estimate for Guyana, while the finfish model was used to generate the estimate for Suriname. For Guyana, the predicted elasticity (Ɛ) is 0.924, which implies a 1.81% loss in shellfish catch per year resulting from the recent loss of mangroves in that country. For Suriname, the predicted elasticity (Ɛ) is 1.77, which implies a 1.34% loss in finfish catch per year resulting from that country’s recent loss of mangroves. These estimated losses in fish catch were calculated by multiplying each country’s elasticity by the observed changes in mangrove area noted previously. The fourth section of this study provides a discussion of the analysis and estimates the benefits of mangrove restoration in each country. If the estimated loss in mangrove area had not occurred in Guyana, the Guyanese fishery would have gained $586,440 in revenue net of costs. Similarly, if the estimated loss in mangrove area had not occurred in Suriname, the fishery in that country would have gained $180,900 in revenue net of costs. This section also provides a comparison to previous mangrove-fishery linkage studies. This is followed by a discussion of limitations of the present study, including the wide variation in mangrove area and mangrove area change estimates found in different sources. Lastly, recommendations for future data collection are provided. The final section of this study provides an insight into mangrove-fishery linkages within the countries of Guyana and Suriname for specific fisheries as well as the associated monetary gains resulting from conserving mangrove area. These estimates are insufficient for determining the total value of conserving mangrove area, but a more complete estimate of total value could be determined by applying valuation methods, similar to those used in this study, to additional ecosystem services.