Journal of Heredity Advance Access originally published online on September 23, 2008
Journal of Heredity 2009 100(1):25-33; doi:10.1093/jhered/esn077
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Original Articles |
Extremely Low Genetic Diversity in the Endangered Hawaiian Monk Seal (Monachus schauinslandi)
From the Department of Zoology and Hawaii Institute of Marine Biology, University of Hawaii, PO Box 1346, Kaneohe, HI 96744 (Schultz, Toonen, and Bowen); and the Pacific Islands Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2570 Dole Street, Honolulu, HI 96822-2396
Address correspondence to J. K. Schultz at the address above, or e-mail: jschultz{at}hawaii.edu.
Hunted to near extinction in the late 19th century, the endangered and endemic Hawaiian monk seal (Monachus schauinslandi) exhibits low variation at all molecular markers tested to date. Here we confirm extreme paucity of genetic diversity, finding polymorphisms at only 8 of 154 microsatellite loci tested (143 novel species-specific loci, 10 loci from Antarctic seals, and 1 previously characterized locus). This screening revealed unprecedentedly low levels of allelic diversity and heterozygosity (A = 1.1, He = 0.026). Subsequent analyses of 2409 Hawaiian monk seals at the 8 polymorphic loci provide evidence for a bottleneck (P = 0.002), but simulations indicate low genetic diversity (He < 0.09) prior to recorded human influence. There is little indication of contemporary inbreeding (FIS = 0.018) or population structure (K = 1 population). Minimal genetic variation did not prevent partial recovery by the late 1950s and may not be driving the current population decline to 
1200 seals. Nonetheless, genotyping nearly every individual living during the past 25 years sets a new benchmark for low genetic diversity in an endangered species.
Corresponding Editor: C. Scott Baker
Received May 1, 2008
Accepted August 26, 2008