| Summary | Stocks of Atlantic Bluefin Tuna that spawn in the western Atlantic ocean |
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| Project | SESMAD |
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| Subtype | Natural Resource Unit |
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| Sector | Fisheries (Stock-specific) |
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| Biotic | Yes |
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| Explanation | |
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| Commons Aggregation | Population |
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| Explanation | Western Bluefin tuna are a subpopulation of the species Thunnus thynnus that spawns in the Western Atlantic Ocean (i.e. the Americas) |
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| Commons Boundaries | Very unclear boundaries (1) |
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| Explanation | Although the Western Atlantic Bluefin Tuna spawns in the Western Atlantic, they mix with the Eastern stock on feeding grounds. The extent of mixing is generally unknown. |
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| Commons Unit Size | Medium (3) |
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| Explanation | Adult bluefin tuna weigh up to 900 kg, although the average adult weighs in at around 250kg and is 2.5m in length. |
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| Environmental Medium | Oceanic |
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| Explanation | |
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| Inter Annual Predictability | Moderate (2) |
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| Explanation | The availability of Western Atlantic Bluefin Tuna can be predicted using scientific methodologies such as virtual population analysis. However, these figures are highly contested, and several uncertainties remain. Nonetheless, relative magnitudes can be assessed given a consistent methodology. |
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| Intra Annual Predictability | High (3) |
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| Explanation | There is little seasonal variation in resource availability. |
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| Commons Renewability | Renewable (1) |
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| Explanation | |
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| Productivity | Moderately Productive (2) |
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| Explanation | The Western Atlantic Bluefin Tuna is moderately productive meaning it can sustain a commercial fishery, but at levels far below Eastern Stock. The sustainability of a commercial fishery is contested by some who argue that the stock ought to be listed on CITES. |
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| Commons Accessibility | Very accessible (3) |
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| Explanation | Although Western Atlantic Bluefin Tuna are located throughout the Western Atlantic Ocean, they are easily accessible for modern oceanic fishing fleets that target them. |
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| Commons Heterogeneity | High (3) |
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| Explanation | Adult Western Atlantic Bluefin tuna congregate in the Gulf of Mexico during the spawning season. However, for the rest of the year they are distributed widely throughout the Western Atlantic. |
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| Commons Mobility | High (3) |
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| Explanation | Western Atlantic Bluefin Tuna travel throughout the Western Atlantic Ocean, and migrate across into the Eastern Atlantic. They can reach speeds of up to 60 km/h. |
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| Commons Spatial Extent | 106000000 |
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| Explanation | This is the approximate size of the Atlantic Ocean and Mediterranean Sea. Although they are more concentrated in the Western Atlantic, they may occur throughout much of this range in small numbers. |
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| Technical Substitute | No |
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| Explanation | |
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