A sex ratio based assessment of common minke whales
The sex ratio in the West Greenland catch history of the common minke whale (Balaenoptera acutorostrata) is used to assess the current status of the common minke whale population that supplies the West Greenland hunt. The female fraction in common minke whale foetuses is around 1/2, but the fraction...
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| Format: | Text |
| Language: | English |
| Published: |
2006
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.424.4038 http://www.iwcoffice.co.uk/_documents/sci_com/SC58docs/sc-58-awmp3.pdf |
| Summary: | The sex ratio in the West Greenland catch history of the common minke whale (Balaenoptera acutorostrata) is used to assess the current status of the common minke whale population that supplies the West Greenland hunt. The female fraction in common minke whale foetuses is around 1/2, but the fraction in the West Greenland catch has varied around 3/4 since the beginning of the hunt in 1948. This difference is likely to reflect sex specific behaviour, where females tend to occur in other areas than males, but it may also reflect a female selective hunt and/or a female bias in the sex ratio at birth. These hypotheses were examined by trial simulations, where an age- and sex-structured population model with density regulated dynamics were set to cover a maximum sustainable yield rates between 1 % and 7%, a current abundance between 800 and 50, 000 females, different degrees of female bias in the sex specific dispersal, a sex specific hunt, a female bias in the sex ratio at birth, increasing trends in the female bias of a sex specific dispersal and a sex specific hunt, and a uniform, increasing and decreasing age-selectivity in the hunt. Given the trials and the data is it concluded that a current abundance in the order of 20, 000 individuals is a conservative estimate, and that a current catch of 175 individuals most likely is sustainable. |
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