Quantifying welfare gains of coastal and estuarine ecosystem rehabilitation for recreational fisheries

Sustainably developing global blue carbon for climate change mitigation and economic benefits through international cooperation

Blue carbon is the carbon storage in vegetated coastal ecosystems such as mangroves, salt marshes, and seagrass. It is gaining global attention as its role in climate change mitigation and local welfare growth. However, a global assessment on the long-term spatiotemporal sustainable development status of blue carbon has not been conducted, and the relations among blue carbon ecosystems, driving forces for climate change mitigation, and socioeconomic interventions for development capacity on a global scale are still unclear. Here, we constructed a blue carbon development index (BCDI), comprising three subsystems: driving force, resource endowment, and development capacity, to assess the sustainable development level of 136 coastal countries' blue carbon over 24 consecutive years and explore the relationship among subsystems. We further propose a cooperation model to explore the feasibility of global blue carbon cooperation and quantify benefit allocation to specific countries. The results showed an upward trend in BCDI scores with variations in regional performance over the past two decades, and we found a positive correlation between development capacity and blue carbon resource endowment. Based on the scenario simulations of global cooperation, we found that coastal countries could improve the global average BCDI score, add 2.96 Mt of annual carbon sequestration, and generate $136.34 million in 2030 under Global Deep Cooperation scenario compared with the Business-As-Usual scenario.

Estimation and use of recreational fishing values in management decisions

In many countries, commercial and recreational fishing compete for access to marine resources. In some cases, recreational catch outweighs commercial harvest and may threaten species otherwise protected from commercial fishing. This has led to increasing calls for improved management of recreational fishing in the broader context of general fisheries management. As a result, fisheries managers face the challenge to decide how to allocate the available marine resources between competing uses. In this paper, we review and explain two common approaches that have been used to support recreational fishing allocation decisions. While economic activity analysis is an appropriate tool to assess how a change in resource allocation would affect regional economic activity (economic contributions and impacts), it is ill-suited to assess associated gains or losses in welfare of society as a whole (economic efficiency). Hence, economic activity analysis and social cost-benefit analysis complement each other, with each providing a different set of information answering a different set of questions. Unfortunately, both types of analysis use the term "economic value" suggesting that they are alternative approaches that provide the same information, whereas in fact they are not. If the objective of fishery managers is to ensure that society as a whole is made better off, the appropriate metric is economic value as defined by welfare economics. Under this definition, all goods and services provided by marine resources that are beneficial to humans have economic value. This includes non-use values such as the continued existence of an endangered marine species. The aim of this paper is to support managers and policymakers in allocating marine resources by reviewing relevant economic principles, concepts, and tools in the context of recreational fishing, including the use and challenges of estimating the non-market benefits generated by recreational fishing experiences.

Estimating the recreational value of a coastal wetland park: Application of the choice experiment method and travel cost interval analysis

Estimating the recreational value of a coastal wetland park is useful in understanding wetland ecosystem and nurturing a balanced relationship between wetland tourism exploration and natural conservation. This study aims to apply appropriate methodologies to accurately estimate the recreational value of a coastal wetland park. The Nansha Wetland in China was used as the study site, and its recreational value was divided into non-use value (estimated using the choice experiment method (CEM)) and use value (estimated using travel cost interval analysis (TCIA)). The data were collected via questionnaires consisting of different choice experiment scenarios and travel cost investigations. The results showed that the per capita and total non-use values were 116.97 CNY/17.80 USD and 24.56 million CNY/3.74 million USD, respectively, and the per capita and total use values were 313.95 CNY/47.79 USD and 65.93 million CNY/10.04 million USD. Therefore, the per capita and total recreational values were 430.92 CNY/65.59 USD and 90.49 million CNY/13.77 million USD. CEM was used to identify tourists' trade-offs and preferences among the selected wetland attributes. As a result, tourists were found to have the largest marginal willingness to pay (MWTP) for "mangrove coverage," followed by "species of rare birds" and "water visibility." TCIA was used to solve the under-dispersion problem of the number of trips. Based on these findings, several managerial implications were identified, including adjusting ticket price based on the non-use value, regulating tourists' behaviors, enhancing the protection of mangroves, improving the water quality and the living habitats of migrant birds, and promoting science education and popularization.

Nutrient loading diminishes the dissolved organic carbon drawdown capacity of seagrass ecosystems

Seawater dissolved organic carbon (DOC) in seagrass meadows is gaining attention for its role in carbon sequestration. Abundant refractory compounds in DOC are exported by seagrass meadows to the deep sea, thereby contributing to long-term carbon drawdown. DOC lability and bacterioplankton communities are key determining factors in this carbon sequestration process, and it has been hypothesized that these may be affected by nutrient loading - however, scientific evidence is so far weak. Here, we studied the response of DOC composition and bacterioplankton communities to nutrient loading in seagrass meadows of the South China Sea. We found that increasing nutrient loads enhanced nitrogen and phosphorus concentrations in DOC, which promoted algae blooms (i.e. epiphyte, phytoplankton and macroalgae) in seagrass meadows, and presumably increased the lability of DOC and its bioavailability to microbes. Also, the relative abundance of K-strategist bacterioplankton communities with the potential to degrade refractory compounds (Acidimicrobiia, Verrucomicrobiales and Micrococcales) increased in the seagrass meadows exposed to high nutrient loads. These results suggest that high nutrient loading can enhance labile DOC composition, and thus increase refractory DOC remineralization rate, thereby weakening the DOC contribution potential of seagrass meadows to long-term carbon sequestration.