Browsing by Subject "Humpback whales, Bayesian assessment"

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    Open Access
    A Bayesian assessment of the west and east Australian breeding populations (stocks D and E) of Southern Hemisphere humpback whales
    (International Whaling Commission, 2005) Johnston, Susan J; Butterworth, Doug S
    A Bayesian assessment of breeding stocks D and E shows qualitatively similar results to those presented previously using maximum likelihood methodology, although (in posterior median terms) breeding stock D is indicated to be a little less recovered than in these previous assessments. Current estimates of abundance relative to pristine are shown to be somewhat sensitive to the two alternate historic catch records currently put forward for south of 40 0 S. A posterior distribution for the maximum growth rate parameter r is developed. This posterior could be used as a prior for similar Bayesian assessments of other southern hemisphere humpback populations for which little or no information on increase rates is available.
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    Open Access
    Further assessments of the Southern Hemisphere humpback whale breeding stock C and its component sub-stocks
    (2007) Johnston, Susan J; Butterworth, Doug S
    Bayesian stock assessment results for breeding sub-stocks C1 and C2+3 are presented. Two modelling approaches are applied – one which treats the stocks independently, and another which allows mixing on the feeding grounds.
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    Open Access
    Initial stock assessments of the Southern Hemisphere humpback whale breeding sub-stock B1
    (2007) Johnston, Susan J; Butterworth, Doug S
    Initial Bayesian stock assessment results for humpback breeding sub-stock B1 are presented. These suggest this population presently to be within the range of 60-90% of its pre-exploitation size in terms of point estimates.