How few whales were there after whaling? Inference from contemporary mtDNA diversity

摘要: Reconstructing the history of exploited populations whales requires fitting a trajectory through at least three points in time: (i) prior to exploitation, when abundance is assumed be maximum allowed by environmental carrying capacity; (ii) point minimum or ‘bottleneck’, usually near time protection abandonment hunt; and (iii) present, protected are have undergone some recovery. As historical unknown, this must extrapolated according population dynamic model using catch records, an rate increase estimate current abundance, all which received considerable attention International Whaling Commission (IWC). Relatively little has been given estimating (Nmin), although it clear that genetic demographic forces critical potential for recovery extinction local population. We present general analytical framework improve estimates Nmin number mtDNA haplotypes (maternal lineages) surviving contemporary other species. demonstrate informative parameter as posteriori constraint on Bayesian logistic models based IWC Comprehensive Assessment intensively southern right (Eubalaena australis) published surveys diversity Estimated trajectories from scenarios suggested substantial loss haplotype richness result 19th century commercial whaling 20th illegal Soviet Union. However, relatively high rates used assessment predicted bottleneck was implausibly narrow (median, 67 mature females), our corrected Nmin. Further, levels remnant sequence (theta) pre-exploitation larger than record, known incomplete. Our results need better integrate evolutionary processes into account uncertainty influence maternal fidelity metapopulation dynamics, inverse density dependence (an ‘Allee effect’) severely depleted populations.