Abstract: Monk seals (genus Monachus) are among the most endangered mammals in the world, with all species sharing a similar history of anthropogenic overexploitation. Reductions in population abundance have been accompanied by the loss of genetic diversity in Mediterranean (M. monachus) and Hawaiian (M. schauinslandi) monk seals. Both species are characterized by extremely low variability at all genetic markers tested to date, including microsatellite loci, the mitochondrial control region, and major histocompatibility complex class I genes. Genetic variation is partitioned differently in the two species. The Hawaiian monk seal does not exhibit spatial population structure throughout its range in the Hawaiian Archipelago (F_ST = 0.00); therefore, it is unlikely that the translocation of monk seals will result in genetic incompatibilities. In contrast, Eastern Mediterranean and Western Saharan M. monachus populations are reproductively isolated (F_ST = 0.56), though the distribution of alleles likely signifies a once contiguous range sundered by the extirpation of geographically intermediate subpopulations. Given the magnitude of genetic differentiation, moving Mediterranean monk seals between eastern and western populations could result in reduced overall fitness; additional data is required to assess the risk of moving monk seals within a population (e.g., the Eastern Mediterranean). Recent advances in genomics will facilitate future investigation into the reproductive success of both species and guide managers in their quest to recover Mediterranean and Hawaiian monk seal populations.

Key Words: monk seal, conservation, DNA, genetic diversity, pinniped, stock structure

Document Type: Research article

DOI: 10.1578/AM.37.3.2011.227

Page Numbers: 227-235