SUMMARY
The assessment of North Atlantic bluefin tuna has been based on the assumption that two separate populations of bluefin tuna exist in the North Atlantic, one on the west and another on the east part of the Atlantic (including the Mediterranean Sea), and that the mixing of the two populations is limi...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.476.8068 http://www.iccat.int/Documents/CVSP/CV055_2003/no_3/CV055031055.pdf |
| Summary: | The assessment of North Atlantic bluefin tuna has been based on the assumption that two separate populations of bluefin tuna exist in the North Atlantic, one on the west and another on the east part of the Atlantic (including the Mediterranean Sea), and that the mixing of the two populations is limited. Management measures have been adopted on the basis that the management regime imposed in the western Atlantic does not affect the population of bluefin tuna in the eastern Atlantic and vice versa. Recent tagging data suggest that the migratory patterns of fish from the two populations are much more complex and extensive than it was previously believed. If the degree of mixing of the two stocks is greater than the 1-2 % which is currently assumed, then the recovery of the depleted western stock might not be possible under the existing management regime. A multi-area, fleet-disaggregated, age-structured population dynamics model is used to test this hypothesis and evaluate the effectiveness of existing and alternative management measures under different mixing scenarios. The model simulates the dynamics of the two bluefin tuna stocks in the North Atlantic and of the fisheries that target them and explicitly models the trans-Atlantic migration of the fish. RÉSUMÉ |
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