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We present a new methodology for database-driven ecosystem model generation and apply the methodology to the world's 66 currently defined Large Marine Ecosystems. The method relies on a large number of spatial and temporal databases, including FishBase, SeaLifeBase, as well as several other databases developed notably as part of the Sea Around Us project. The models are formulated using the freely available Ecopath with Ecosim (EwE) modeling approach and software. We tune the models by fitting to available time series data, but recognize that the models represent only a first-generation of database-driven ecosystem models. We use the models to obtain a first estimate of fish biomass in the world's LMEs. The biggest hurdles at present to further model development and validation are insufficient time series trend information, and data on spatial fishing effort.  相似文献   
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The decline of a regional fishing nation: The case of Ghana and West Africa   总被引:1,自引:0,他引:1  
Inadequate trade policies, globalization of the fishing industry, dominance of Europe's distant water fleets, declarations of exclusive economic zones (EEZs) by neighbouring West African nations, overfishing and a lack of good governance contributed to the decline of Ghana as a regional fishing nation, a position it had held since the 18th century. The prohibitive cost of access arrangements limited Ghana's access to distant waters. The country's marine environments have been impacted by overexploitation of stocks and the use of destructive methods. Subsistence fishing has become the sole means of survival for many fishers. The decline of the fishing sector has limited the country's ability to meet domestic demand and threatened the economic and food security of many Ghanaians. The article traces the early history of Ghana's fisheries, their gradual decline during the last four decades, and outlines recommendations for policy changes to address the situation and steer the nation on a course towards sustainable fisheries.  相似文献   
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Ocean-based industries provide employment for nearly 30 % of the population in the North Coast region of British Columbia. Marine resource dependence has raised concerns about the possible economic impacts of a tanker spill along the proposed Enbridge Northern Gateway shipping route, which would export 525,000 barrels (bbls) per day of oil, bitumen, and condensate from Kitimat, British Columbia, to international markets. This study uses current and projected future values of four ocean-based industries and the Enbridge Northern Gateway project to estimate total (i.e., direct, indirect, and induced) economic effects on total output, employment, and gross domestic product (GDP) and impacts on the regional economy over a 50-year period under three potential spill scenarios: no impact (no spill), medium impact (a 63,000-bbl spill), and high impact (a 257,000-bbl spill). The proposed Enbridge Northern Gateway project could produce total positive economic effects of $600 million in output, 5,700–8,400 person years (PYs) of employment, and $300 million in GDP in the North Coast region. A medium impact tanker spill could cause losses of $40–$190 million in output, 400–1,500 PYs of employment, and $20–$100 million in GDP, and a high-impact spill could cause losses of $90–$300 million in output, 1,650–4,500 PYs of employment, and $70–$200 million in GDP.  相似文献   
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Regional Environmental Change - There is a critical need to develop effective strategies for the long-term sustainability of Canada’s oceans. However, this is challenged by uncertainty over...  相似文献   
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Sustainable provision of seafood from wild-capture fisheries and mariculture is a fundamental component of healthy marine ecosystems and a major component of the Ocean Health Index. Here we critically review the food provision model of the Ocean Health Index, and explore the implications of knowledge gaps, scale of analysis, choice of reference points, measures of sustainability, and quality of input data. Global patterns for fisheries are positively related to human development and latitude, whereas patterns for mariculture are most closely associated with economic importance of seafood. Sensitivity analyses show that scores are robust to several model assumptions, but highly sensitive to choice of reference points and, for fisheries, extent of time series available to estimate landings. We show how results for sustainable seafood may be interpreted and used, and we evaluate which modifications show the greatest potential for improvements.  相似文献   
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The announcement of plans for exploratory oil drilling at a number of offshore sites in Belize raised concerns about the risks associated with drilling, particularly given the socio‐economic importance of the marine ecosystem. The current economic value of fisheries and marine ecotourism is estimated, along with the potential revenue from offshore oil and potential economic losses stemming from oil pollution, under various assumptions on risk and uncertainty. Marine fisheries and ecotourism are estimated to generate around US$ 183 million per year. Single‐year estimated maximum revenue is higher for oil extraction initially but quickly declines; during a 50 year (two generation) period, total discounted benefits from marine fisheries and ecotourism are estimated at US$ 5.1 billion, compared to US$ 3.2 billion from offshore oil revenue. Following a hypothetical oil spill, discounted losses in marine fisheries and ecotourism due to perception and ecological impacts are estimated at US$ 912 million, with clean‐up costs and capital losses of US$ 6.1‐10.4 billion. Considering the short extraction life of oil resources compared to fisheries and ecotourism, the difference in benefits increases substantially in favour of the latter with a longer time horizon. A recent public referendum resulted in a 98% vote against oil exploration and a subsequent annulment of oil concessions pending environmental impact assessments.  相似文献   
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