Valuing Mangrove-Fishery Linkages – A Case Study of Campeche, Mexico

This paper explores the value of mangrove systems as a breeding and nursery habitat for off-shore fisheries, focusing on mangrove-shrimp production linkages in Campeche State, Mexico. We develop an open access fishery model to account explicitly for the effect of mangrove area on carrying capacity and thus production. From the long-run equilibrium conditions of the model we are able to establish the key parameters determining the comparative static effects of a change in mangrove area on this equilibrium. We then estimate empirically the effects of changes in mangrove area in the Laguna de Terminos on the production and value of shrimp harvests in Campeche over 1980–90. Our findings suggest that mangroves are an important and essential input into the Campeche shrimp fishery, but that the low levels of deforestation between 1980 and 1990 mean that the resulting losses to the shrimp fishery are still comparatively small. Over-exploitation of the fishery due to open access conditions remains the more pervasive threat, and without better management any long-run benefits of protecting mangrove habitat are likely to be dissipated.     

Use of system dynamics modelling in design of an environmental restoration banking institution

This paper describes a system dynamics model developed to inform design of a proposed environmental restoration banking system. The purpose of the proposed system is to facilitate restoration of extensive areas of mangrove forests that have been cleared or damaged in large part by expansion of the commercial shrimp farming industry. A case study is developed for mangrove restoration in Thailand; however, the model is seen as applicable to a number of countries which have experienced severe mangrove loss. The scheme is based on environmental mitigation banking principles, in which users of an environmental resource are required to purchase from a mitigation bank credits representing restorations undertaken to compensate for environmental damage, thereby achieving “no net loss” of the environmental asset. The scheme proposed in this paper differs from usual mitigation banking practise in that the objective is to restore large degraded areas over and above present rates of consumption. Model simulations show that the restoration banking system may be effective in restoring coastal mangroves and in rehabilitating the coastal shrimp farming industry that is dependent on environmental services provided by the mangrove stock.     

Preservation or Conversion? Valuation and Evaluation of a Mangrove forest in the Philippines

Mangrove ecosystems are rapidly declining in many parts of the world. This has resulted in the loss of important environmental and economic products and services including forest products, flood mitigation and nursery grounds for fish. The aquaculture industry was the single biggest threat to mangroves in the Philippines until 1981 when conversion of the remaining mangrove stands was prohibited by law. However, the decreasing yield from capture fisheries is putting pressure for the re-examination of this policy. To understand the importance of mangroves, insight is needed into the value of products and services provided is needed. This article compares the costs and benefits of mangrove preservation with those generated by alternative uses such as aquaculture and forestry. Equity and sustainability objectives are taken into account, in addition to economic efficiency and analyzed according to the perspectives of the different types of decision makers involved.     

Modelling economy-ecology linkages in mangroves: Economic evidence for promoting conservation in Bintuni Bay, Indonesia

Woodchip exports pose a potential threat to a 300 000-ha mangrove ecosystem in the Bintuni Bay area of Irian Jaya, Indonesia. The bay supports an important shrimp export industry, and coastal areas support 3000 households. Traditional non-commercial uses of mangroves have an estimated value of Rp20 billion/yr (US$10 million/yr); commercial fisheries are valued at Rp70 billion/yr (US$35 million/yr) and selective commercial mangrove cutting schemes have a maximum value of Rp40 billion/yr (US$20 million/yr).Forest management options, ranging from clear cutting to a cutting ban, are evaluated in a cost–benefit analysis incorporating linkages among mangrove conversion, offshore fishery productivity, traditional uses, and benefits of erosion control and biodiversity maintenance functions. “Linkage scenarios” are developed that reflect potential ecosystem component interactions in Bintuni Bay. Clear cutting is optimal only if linkages are ignored. A cutting ban is optimal if linear and immediate linkages between ecosystem components exist. Under a scenario with linear but delayed linkages of 5 years, selective cutting of 25% of the harvestable mangrove is the optimal strategy; it has a present value of Rp70 billion (US$35 million) greater than the clear cutting option, and more extensive cutting would yield no additional net benefits.Strong economic arguments exist for conservative mangrove clearing. Where strong ecological linkages occur, severe restrictions on clearing activities will be economically optimal. Where ecosystem dynamics are uncertain, programs reducing linkage effects – such as greenbelts, replanting, or selective cutting – will minimise potential economic losses.     

Development and government policies of the shrimp farming industry in Thailand in relation to mangrove ecosystems

Intensive shrimp farming arrived in Thailand during the 1980s and developed virtually unregulated until 1987. Subsidised by the government, it quickly became an important export industry and Thailand has been the world's largest producer of tiger shrimp since 1991. However, the development of the shrimp farming industry in Thailand over the last 20 years in relation to its use of mangrove ecosystems is an example of sequential exploitation of natural resources witnessed through the shift in farm development from one region to another. This sequential exploitation has caused widespread degradation of mangrove ecosystems, and the benefits of the industry may be less than perceived as a result of subsidies and environmental and social impacts. This study follows the development of shrimp farming in Thailand from the 1940s to 1997 and studies national legislation and associated government policy as examples of driving forces behind this development. From our findings it appears that the development of legislation has not followed the same pace as the development of the industry, neither temporally, nor in content nor implementation, and contradictory policies have arisen.     

HABITAT–FISHERY LINKAGES AND MANGROVE LOSS IN THAILAND

The article develops a dynamic model of habitat–fishery linkage in which the habitat is being converted. The basic model is applied to a case study of the impacts of mangrove deforestation on the artisanal marine demersal and shellfish fisheries in Thailand. The comparative static effects of a change in mangrove area on the long-run equilibrium level of effort and fish stocks, as well as on the resulting market harvesting supply of the fishery, are determined. By estimating parameters through pooled timE-series and cross-sectional data over the 1983–96 period for the five coastal zones along the Gulf of Thailand and Andaman Sea, the welfare impacts of mangrove deforestation are estimated. Mangrove conversion is expected to be a function of the return to shrimp farming and the input costs to farming shrimp, plus exogenous economic factors. The resulting aggregate reduced-form level of mangrove clearing by all farmers in coastal areas is empirically estimated across the five coastal zones in Thailand over 1983–96. The policy implications of the findings are discussed with respect to Thailand and the modeling of habitat–fishery linkages.     

Illuminating the need for ecological knowledge in economic valuation of mangroves under different management regimes — a critique

This is a commentary on a paper by Gilbert and Janssen (Gilbert, A.J., Janssen, R., 1998. Ecol. Econ. 25, 323–346) that deals with valuation of management alternatives for the Pagbilao mangroves, Philippines. Our main critique focuses on the undervaluation of fisheries as well as the inability to quantify the value of ecological services and internalize aquaculture's environmental costs. In addition, the sustainability criteria set up for the aquaculture management alternatives is open to debate. These weaknesses affect the result of Gilbert and Janssen's analysis so that the value of the unexploited mangrove forest is underestimated, and the value and sustainability of converting the forest into aquaculture ponds are overestimated. If applied to decision-making, the erroneous results from this partial cost–benefit analysis may have dire consequences for the mangroves and coastal communities of Pagbilao.     

福建红树林资源的现状与保护

福建是我国目前红树林自然分布最北的一个省份,也是我国人工营造红树林历史最悠久的一个省份;福建的红树植物均为比较耐寒的种类,有５科６属７种,分布面积为２６０ｈ;红树林资源具有明显的生态效益和经济价值;但目前福建省的红树林资源受到严重破坏,保护和恢复显得尤为重要     

Development and conservation of Philippine mangroves: institutional issues

The decline of Philippine mangroves from half a million hectares in 1918 to only 120 000 ha in 1994 may be traced to local exploitation for fuelwood and conversion to agriculture, salt beds, industry and settlements. But brackishwater pond culture, whose history is intertwined with that of mangroves, remains the major cause of loss. The paper discusses the institutional issues — aquaculture as development strategy, low economic rent of mangroves, overlapping bureaucracy and conflicting policies, corruption, weak law enforcement and lack of political will — relevant to this decline. Recommended policies are based on these institutional factors and the experiences in mangrove rehabilitation including community-based efforts and government programs such as the 1984 Central Visayas Regional Project. These recommendations include conservation of remaining mangroves, rehabilitation of degraded sites including abandoned ponds, mangrove-friendly aquaculture, community-based and integrated coastal area management, and provision of tenurial instruments.     

The economics of the adoption of BMPs: the case of mariculture water management

How shrimp mariculture interacts with the natural environment is a topic receiving growing attention from industry members and environmental organizations. The farms’ use of water, and subsequent discharge problems, represent important inter- and intra-industry externalities. The non-point source nature of the pollution problem suggests direct effluent regulation is unfeasible, and voluntary adoption of best management practices is the current approach favored by the industry and international organizations. This paper provides an in-depth analysis of one such management practice, reduced water exchange. Significant reductions in pond pumping diesel costs, alongside possible reductions in pond productivity and shrimp size, are expected from this technique. Social benefits could follow from the reduction of nitrogen and other effluent loadings. But adoption problems are expected due to the current inability to value longer-term private and social benefits of the practice and the risk-creating nature of the technique. Voluntary compliance with sustainable practices could be enhanced by complementary policy tools and a role of governments in coastal zone management.     

南海地区红树林资源的利用现状及生态保育对策

南海地区是全球红树林分布的中心之一,该区红树林面积大约占全球的28%,红树植物的多样性为世界最高,共有46种真红树分布于此。由于人口增加和经济发展的巨大压力,南海地区红树林资源破坏严重,退化趋势明显。本区红树林的平均年损失率为1.7%,比全球平均损失率高35%。本文在对南海地区红树林资源的利用现状和退化原因进行分析的基础上,提出南海地区红树林资源保护与管理的对策,以期能在双边和区域的层面上共同协作,采取适当的措施去扭转南海地区红树林生境的退化趋势。     

In the wake of tsunami: Lessons learned from the household decision to replant mangroves in Thailand

The Indian Ocean tsunami has increased interest in replanting mangroves as natural storm barriers. This paper analyzes the household decision to replant mangroves in four case study villages in Thailand in line with existing studies on the voluntary contribution to step-level public goods and the decision by adult members of a household to devote some labor to an outside activity. The null hypothesis that dependency on mangrove-based income has no influence on participation in replanting is rejected. Awareness of community conservation efforts and of the environmental impacts of shrimp farms also motivates participation. Allocation of male and female labors to replanting is also found to be jointly determined.     

Does Economic Development Lead to Mangrove Loss? A Cross‐Country Analysis

Mangroves line one quarter of the world's tropical coastlines, and approximately 117 countries and territories have mangrove resources within their borders. Although over recent years mangrove deforestation has occurred at a phenomenal rate worldwide, there have been few economic studies of the underlying causes. The article attempts such an analysis and particularly examines the role of economic development, with specific reference to those activities that may result in mangrove deforestation, in determining the area of mangrove left within a country. The article develops a model of economic activity and mangrove conversion. From this model, a relationship is established between remaining mangrove area, economic activity, and other important causative factors. The mangrove area relationship is estimated empirically for a cross-section of 89 countries. Results show that shrimp aquaculture and agriculture are significantly associated with mangrove loss across all countries, whereas the higher the level of GDP per capita the more mangrove area remains. The number of protected areas, length of coastline and political stability were also important in determining the remaining mangrove area of a country. (JEL O13 , Q22 , Q23 , Q24 )     

Did the Thai rice-pledging programme improve the economic performance and viability of rice farming?

This article evaluates impacts of the rice-pledging programme on the economic performance and viability of rice farming in Thailand. It also investigates whether the effects of the programme are heterogeneous across different farm types using the propensity score matching technique to address the self-selection bias in the farm-level data set. We found that the programme enhanced the economic performance less than hoped for. Overall, the programme was estimated to improve the net direct farm income for participating farms by $175.12–$194.82 per hectare. Taking into account the heterogeneous effects of the programme across farm types, we calculated that the greatest effects may be realized by farmers within the small farms subsample, at $404.41–$439.85 per hectare, but only $139.80–$213.36 per hectare for midsize farms, and $138.82–$173.34 per hectare for large farms. With regard to the economic viability of the programme, we discovered that it had an insignificant effect on farm modernization investment initiatives. Thus, future strategies incorporated into the programme that better control increases in production costs, improve small farmers’ access to the programme and require participating farms to spend a portion of the money received on farm modernization may improve long-run benefits of the programme.     

Structural Change in Rural Croatia—Is Early Retirement An Option?

Structural change in agriculture, although often connected with social hardship of uncompetitive small-scale farms and a loss of tradition, is inevitable. It is the basis for successful rural development. We discuss whether early retirement schemes (ERS) are a good value for public money in terms of the necessary adaptations of the farming sector in the course of economic development, and if they are an option for the EU candidate country Croatia. In Croatia, the small scale farm structure leads to widely uncompetitive farms. A study on farmers’ socioeconomic situation as well as actual and expected reactions to policy support is based on results of a household survey. The sample includes farm households from two Croatian regions: The peri-urban Zagreb county and the typically rural region of Bjelovar-Bilogora. Despite unfavourable economic conditions and insufficient farm incomes, rural people are often reluctant to give up farming. We present results on the age structure, income and production structure of farms and farmers’ likely reactions on ERS. We discuss incentives which push farmers to leave the farming sector and ask in which direction farm families plan their future. We conclude with a synthesis of the theoretical advantages and disadvantages of early retirement schemes and link them with possible outcomes in the Croatian case.     

Institutional incentives for managing the landscape: Inducing cooperation for the production of ecosystem services

Agricultural landscapes hold tremendous potential for producing a diverse stream of ecosystem services. Yet, because the spatial configuration of particular ecosystems is critical to the supply of many services, realizing this potential requires that farms be managed in a coordinated way across landscapes rather than as independent units. Under existing incentive programs, this level of coordination is typically neither required nor encouraged.Here we explore how to achieve such coordination from an institutional perspective using voluntary incentives rather than regulation. We focus on three services operating at contrasting scales, from local to global: pollination, hydrologic services, and carbon sequestration. First, we briefly illustrate how agricultural practices can diminish or enhance their provision. Next, we show how all three services require coordinated, landscape-scale management because provision depends upon particular spatial configurations, of which we provide several stylized examples. Finally, based on these stylized configurations, we evaluate the relative merits of three incentive designs-the “cooperation bonus,” the “entrepreneur,” and the “ecosystem service district”-to promote cross-farm cooperation to enhance service provision.All three incentive systems rely on rational self-interest, have cooperative configurations to promote ecosystem services across different scales, use tiered reward systems, and have a major voluntary element. They are distinct in certain key features. The cooperation bonus system rewards conservation even without cooperation but adds a bonus for cooperation. In the entrepreneur incentive, all tiers of reward are contingent upon cooperation. The ecosystem service district scheme is only partially voluntary and forces cooperation of all landowners once the district is formed. Our analysis of these heuristic alternatives integrates biophysical, economic, and institutional factors with the aim of addressing the suite of institutional barriers for landscape-scale management.     

Valuing the environment as input: review of applications to mangrove-fishery linkages

The following paper reviews recent developments in the methodology for valuing the role of wetlands in supporting economic activity. The main focus will be on mangroves serving as a breeding ground and nursery habitat in support of coastal and marine fisheries. As this particular ecological function of a mangrove system means that it is effectively an unpriced ‘environmental’ input into fisheries, then it is possible to value this contribution through applying the production function approach. The first half of the paper overviews the procedure for valuing the environment as an input, applied to the case of a wetland supporting a fishery. Both the ‘static’ Ellis–Fisher–Freeman approach and the ‘dynamic’ approach developed by Barbier and Strand, incorporating the intertemporal bioeconomic fishing problem, are reviewed. The second half of the paper discusses briefly two recent case studies of mangrove-fishery valuation. An application in South Thailand, which is based on the static Ellis–Fisher–Freeman model, and an application in Campeche, Mexico, which is based on the dynamic approach.     

自然圣境的生态保护功能及其实现路径

自然圣境是对人类具有特殊精神意义的自然区域,自然圣境除了具有精神文化价值,在生态环境保护方面也发挥了重要作用。自然圣境的生态保护功能主要体现在保护生态环境和自然资源以及为珍稀濒危物种提供栖息地。目前,因旅游和工程项目过度开发、土地利用变化、所属权转移、价值观念的变化和自然环境变迁等因素,造成自然圣境的生态保护功能面临挑战。面对这些问题,应加强对自然圣境及其生态保护功能的正确认知,将自然圣境纳入保护地和生态补偿体系当中,发挥自然圣境生态文化的灵魂作用,并制定与自然圣境保护相关的法律法规。     

Wage-distance regulation in social-welfare programs: An option-theory perspective

It is often argued that low-skilled workers have an incentive to escape to the unofficial sector if welfare benefits come too close to the net wage in the official sector. Upper limits of welfare benefits often serve as an instrument to ensure a sufficiently high income differnetial between sectors. However, if unofficial-sector income is insecure, and if a change of sectors is costly, an option value of working in the official sector has to be taken into account. This option value reduces the incentive for lowly skilled workers to give up official-sector jobs. Upper limits of welfare benefits might therefore be defined less restrictively.     

Productivity,technical efficiency and technological change in French agriculture during 2002-2015: a Färe-Primont index decomposition using group frontiers and meta-frontier

The objective of the article is to assess productivity change in French agriculture during 2002–2015; namely, total factor productivity (TFP) change and its components – technological change and efficiency change. For this, we use the Färe-Primont index which verifies the multiplicatively completeness property and is also transitive, allowing for multi-temporal and -lateral comparisons. We investigate the extent of heterogeneity within each type of farming sub-sample in terms of TFP change, with the help of the Herfindahl-Hirschman index (HHI). In addition, to compare the technologies among the five types of farming considered, we extend our analysis to the meta-frontier framework. Results indicate that during 2002–2015, all farms experienced TFP progress. The smallest average increase was experienced by the dairy farms and the largest by the field crop farms and the beef farms. The latter had the strongest technological progress but a deterioration in efficiency, while the opposite was found for field crop farms. The analysis of HHI reveals that sheep or goat farms are the most homogenous in terms of the direction of TFP change experienced over the period 2002–2015. The meta-frontier analysis shows that field crop farms’ technology is the most productive of all the types of farming.