SC/60/SH10 Minimum bottleneck abundance of Antarctic blue whales based on current mtDNA diversity

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.582.52; http://www.iwcoffice.co.uk/_documents/sci_com/SC60docs/SC-60-SH10.pdf

A lower bound for the bottleneck population size of Antarctic blue whales is estimated using the current mitochondrial DNA haplotype diversity in the extant population. The method relies on the observation that each of the 26 haplotypes in the current population represents at least one surviving female at the time of the bottleneck. Conservative correction factors are used to extrapolate from these 26 haplotypes to a lower bound on the bottleneck population. Correcting for low sample effort increases the number of haplotypes to 51, to which are applied multiplicative factors of 1.29 for haplotypes missed because of short mtDNA sequences, 2.11 for the sex ratio in the bottleneck population, 1.50 for overlapping generations in the bottleneck population, and 1.03 for haplotypes that went extinct after the bottleneck. The resulting lower bound of 214, if included in a revised assessment of Antarctic blue whales, would probably increase the estimated bottleneck population size, reduce the estimated population rate of increase and increase the estimated pre-exploitation abundance, resulting in a lower ratio of current abundance to pre-exploitation abundance for Antarctic blue whales.