Future impacts of climate change on marine fisheries have the potential to negatively influence a wide range of socio-economic factors, including food security, livelihoods and public health, and even to reshape development trajectories and spark transboundary conflict. Yet there is considerable variability in the vulnerability of countries around the world to these effects. We calculate a vulnerability index of 147 countries by drawing on the most recent data related to the impacts of climate change on marine fisheries. Building on the Intergovernmental Panel on Climate Change framework for vulnerability, we first construct aggregate indices for exposure, sensitivity and adaptive capacity using 12 primary variables. Seven out of the ten most vulnerable countries on the resulting index are Small Island Developing States, and the top quartile of the index includes countries located in Africa (17), Asia (7), North America and the Caribbean (4) and Oceania (8). More than 87% of least developed countries are found within the top half of the vulnerability index, while the bottom half includes all but one of the Organization for Economic Co-operation and Development member states. This is primarily due to the tremendous variation in countries’ adaptive capacity, as no such trends are evident from the exposure or sensitivity indices. A negative correlation exists between vulnerability and per capita carbon emissions, and the clustering of states at different levels of development across the vulnerability index suggests growing barriers to meeting global commitments to reducing inequality, promoting human well-being and ensuring sustainable cities and communities. The index provides a useful tool for prioritizing the allocation of climate finance, as well as activities aimed at capacity building and the transfer of marine technology.

Aquaponics, the symbiotic integration of aquaculture and hydroponics, has been touted as a sustainable food production technology. While there is anecdotal evidence, there are only a few studies on the economics of commercial aquaponics. In this study, we collect economic and production information from three aquaponic farms to investigate the economic feasibility of an aquaponics industry in Hawaii. Based on the information supplied by the farms, we develop a model case to analyze (i) profitability, (ii) return on investment, and (iii) input requirements for small-scale commercial aquaponics operation in Hawaii. We find that small-scale commercial aquaponics is economically feasible, but our findings are not as optimistic as those previously published. The modified internal rate of return of the model farm is 7.36%. We conduct sensitivity and decision reversal analysis to investigate how output prices and operational cost parameters affect the overall economic outcome. We find that economic outcome is very sensitive to output price. Investment in commercial aquaponics cannot be supported if annual sales revenue falls by 11%. We conclude by discussing challenges and risks faced by commercial aquaponic farms and the potential economic gain from organic certification and renewable energy implementation.

This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Wetlands, tidal flats, seaweed beds, and coral reefs are valuable not only as habitats for many species, but also as places where people interact with the sea. Unfortunately, these areas have declined in recent years, so environmental improvement projects to conserve and restore them are being carried out across the world. In this study, we propose a method for quantifying ecosystem services, that is, useful for the proper maintenance and management of artificial tidal flats, a type of environmental improvement project. With this method, a conceptual model of the relationship between each service and related environmental factors in natural and social systems was created, and the relationships between services and environmental factors were clarified. The state of the environmental factors affecting each service was quantified, and the state of those factors was reflected in the evaluation value of the service. As a result, the method can identify which environmental factors need to be improved and if the goal is to increase the value of the targeted tidal flat. The method demonstrates an effective approach in environmental conservation for the restoration and preservation of coastal areas.

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