Health and Disease
The role of infectious disease, parasites, and toxins (anthropogenic and naturally occurring biotoxins) in Hawaiian monk seal population is an ongoing investigation.
MMRP has actively investigated Hawaiian monk seal health and disease for more than 3 decades. This investigation has included surveillance and analysis, primarily in the NWHI. Veterinarians conduct studies including gross necropsy and histopathology, parasitology, hematology, serology, morphometrics, microbiology, epidemiology, scat and spew analysis, population abundance/survival assessment, and reproductive rates. Currently, NOAA Fisheries has joined with a Prescott Grant Award proposal to investigate the health and disease status as well as seal movements in the main Hawaiian Islands.
The three infectious diseases endemic to the MHI considered to have the highest risk for the Hawaiian monk seal population are distemper viruses, Leptospira sp., and Brucella sp. Fortunately, distemper virus in Hawaii is rarely diagnosed in domestic pets. Leptosirosis is endemic and widespread but public awareness and state monitoring are helpful. Also, Hawaiian monk seals are mostly solitary, reducing the potential for the spread of this deadly disease from seal to seal. The potential for Brucella to affect the survival of Hawaiian monk seals is unclear but a cause for concern. Brucella is believed to cause reproductive failure in other species and techniques for diagnosis of Brucella in monk seals and other pinnipeds are being developed and may be available in the near future.
Diseases are constantly emerging and reemerging, and endemic diseases in terrestrial, avian, and other marine mammal species could threaten monk seals. MMRP continues to provide vigilant and timely response to stranded, entangled, sick, and dead monk seals with the help of other state, nongovenrment organizations, and stakeholders.
References for Health and Disease in Hawaiian Monk Seals
Aguirre, A.A., J.S. Reif, and G. A. Antonelis. 1999. Hawaiian monk seal epidemiology plan: health assessment and disease status studies. U.S. Department of Commerce, NOAA Technical Report NMFS NWFSC-280. 63 pp. Aguirre, A.A. 2002. Health assessment and disease status studies of the Hawaiian monk seal (Monachus schauinslandi). National Marine Fisheries Service Center Administrative Report H-00-01 (unpublished). 44 pp. Available from PIFSC, 2570 Dole Street, Honolulu, HI 96822. Antonelis, G. A., J. D. Baker, and J. J. Polovina 2003. Improved body conditions of weaned Hawaiian monk seal pups associated with El Niño events: potential benefits to an endangered species. Mar. Mamm. Sci. 19(3): 590-598. Baker, J.D., and T.C. Johanos. 2002. Effects of research handling on the endangered Hawaiian monk seal. Marine Mammal Science18:500-512. Banish, L.D., and W.G. Gilmartin. 1988. Hematology and serum chemistry of the young Hawaiian monk seal (Monachus schauinslandi). Journal of Wildlife Diseases 24:225-230. Dierauf, L.A., and F. Gulland. 2001. CRC Handbook of Marine Mammal Medicine, Second Edition. CRC Press, Boca Raton, FL. Dailey, M.D., R.V. Santangelo, and W.G. Gilmartin. 1988. A coprological survey of helminth parasites of the Hawaiian monk seal from the Northwestern Hawaiian Islands. Marine Mammal Science 4:125-131. Dailey, M. D. 2002. In Review. Heterophyopsis Hawaiiensis from the Hawaiian monk seal. Gilmartin, W.G., E. Jacobson, W. Karesh, and M. Woodford. 1993. Working group report: monitoring, investigation, and surveillance of disease in free-ranging wildlife. Journal of Zoo and Wildlife Medicine 24:389-393. Gulland, F.M.D. 1999. Leptospirosis in marine mammals. Pages 469-471 in M.E. Fowler and R.E. Miller, eds. Zoo & Wild Animal Medicine Current Therapy 4. W. B. Saunders, Philadelphia, PA. Jahans, K.L., G. Foster, and E.S. Broughton. 1997. The characterization of Brucella strains isolated from marine mammals. Veterinary Microbiology 57:373-382. Whittow, G.C., and G.H. Balazs. 1979. Parasitic ulceration of the stomach in a Hawaiian monk seal (Monachus schauinslandi). 'Elepaio 38:83-84.