HAWAIIAN MONK SEAL (Monachus schauinslandi) STOCK DEFINITION AND GEOGRAPHIC RANGE Hawaiian monk seals are distributed throughout the Northwestern Hawaiian Islands (NWHI) in six main reproductive subpopulations at French Frigate Shoals, Laysan and Lisianski Islands, Pearl and Hermes Reef, and Midway

STOCK DEFINITION AND GEOGRAPHIC RANGE Hawaiian monk seals are distributed throughout the Northwestern Hawaiian Islands (NWHI) in six main reproductive subpopulations at French Frigate Shoals, Laysan and Lisianski Islands, Pearl and Hermes Reef, and Midway and Kure Atoll. Small numbers also occur at Necker, Nihoa, and the main Hawaiian Islands, primarily at Niihau. Genetic variation in Hawaiian monk seals is extremely low and may reflect both a long-term history at low population levels and more recent human influences (Kretzmann et al., 2001). The tendency for genetic drift may have been relatively large, due to the small size of different island/atoll subpopulations. However, 10-15% of these seals migrate among the subpopulations (Johnson and Kridler 1983; National Marine Fisheries Service [NMFS] unpubl. data) and, to some degree, this movement should counter the development of separate genetic stocks. Genetic variation among the different island populations is low (Kretzmann et al., 1997; 2001). Demographically, the different island subpopulations have exhibited considerable independence. For example, abundance at French Frigate Shoals grew rapidly from the 1950s-1980s, while other subpopulations declined rapidly. Variability in past population trends may be partially explained by changes in levels of human disturbance (Gerrodette and Gilmartin 1990; Ragen 1999). Current demographic variability among the subpopulations probably reflects a combination of age structure effects resulting from different recent histories and variable environmental conditions. While research and recovery activities may focus on the problems of single island/atoll subpopulations, the species is managed as a single stock.