Estimating the number of whales entering trade using DNA profiling and capture-recapture analysis of market products

Surveys of commercial markets combined with molecular taxonomy (i.e. molecular monitoring) provide a means to detect products from illegal, unregulated and/or unreported (IUU) exploitation, including the sale of fisheries bycatch and wild meat (bushmeat). Capture-recapture analyses of market products using DNA profiling have the potential to estimate the total number of individuals entering the market. However, these analyses are not directly analogous to those of living individuals because a ‘market individual’ does not die suddenly but, instead, remains available for a time in decreasing quantities, rather like the exponential decay of a radioactive isotope. Here we use mitochondrial DNA (mtDNA) sequences and microsatellite genotypes to individually identify products from North Pacific minke whales (Balaenoptera acutorostrata ssp.) purchased in 12 surveys of markets in the Republic of (South) Korea from 1999 to 2003. By applying a novel capture-recapture model with a decay rate parameter to the 205 unique DNA profiles found among 289 products, we estimated that the total number of whales entering trade across the five-year survey period was 827 (SE, 164; CV, 0.20) and that the average ‘half-life’ of products from an individual whale on the market was 1.82 months (SE, 0.24; CV, 0.13). Our estimate of whales in trade (reflecting the true numbers killed) was significantly greater than the officially reported bycatch of 458 whales for this period. This unregulated exploitation has serious implications for the survival of this genetically distinct coastal population. Although our capture-recapture model was developed for specific application to the Korean whale-meat markets, the exponential decay function could be modified to improve the estimates of trade in other wildmeat or fisheries markets or abundance of living populations by noninvasive genotyping.

Eight Polymorphic Microsatellite Loci Developed and Characterized From Townsend’s Big-Eared Bat, Corynorhinus Townsendii

Two of the five subspecies of the western big-eared bat, Corynorhinus townsendii, are listed as federally endangered with the remaining three being of conservation concern. Knowing the degree of connectivity among populations would aid in the establishment of sound conservation and management plans for this taxon. For this purpose, we have developed and characterized eight polymorphic microsatellite markers.

Development of 10 Polymorphic Microsatellite Loci Isolated From The Mountain Beaver, Aplodontia rufa rufa (Rafinesque)

We developed 10 microsatellite markers for the mountain beaver, Aplodontia rufa rufa. In three populations of A. r. rufa, the number of alleles for these loci ranged from monomorphic to nine. Average observed heterozygosities in these populations ranged from 0.29 to 0.60. We also tested previously published markers from the endangered subspecies A. r. nigra in A. r. rufa populations.

Development and Characterization of 15 Polymorphic Microsatellite Loci Isolated From Rafinesque’s Big-Eared Bat, Corynorhinus rafinesquii

We developed and characterized 15 microsatellite markers for Rafinesque’s big-eared bat, Corynorhinus rafinesquii. In a population from Tennessee, the number of alleles per locus ranged from three to 13 and observed heterozygosities were 0.35 to 0.97 per locus. These loci will provide appropriate variability for estimation of population connectivity, demographic parameters, and genetic diversity for this species of concern.