Channel Islands

Marine mammal and other native wildlife surveys going back to the 1970s, providing baseline data for current research.

 Northern elephant seals were hunted to near extinction in the 19th century. Protection allowed them to recolonize former habitat on islands off California, where the population by the 1970s was increasing more than 14 percent per year. Subsequent surveys found that almost 25,000 northern elephant seal pups were born in the species’ range in Mexico and the United States in 1982 compared to only six known births in 1911.  By 1985, HSWRI researchers observed over 10,000 elephant seal pups born on San Miguel Island alone. Today, the northern elephant seal population has rebounded to approximately the size it was before hunting. It’s estimated that there are 150,000 individuals, with 124,000 in California waters.HSWRI researchers have tracked this animal’s recovery and continuing threats since the 1970s.

Selected Publications:

Antonelis, G.A., Jr., B.S. Stewart, and W.F. Perryman. Foraging characteristics of northern fur seals (Callorhinus ursinus) and California sea lions (Zalophus californianus) in the waters around San Miguel Island, California. Canadian J. Zool. 68:150-158. Jan 1990.

Boyce, W.M., I. Mena, P.K. Yochem, F.M.D. Gulland, A. Garcia-Sastre, N. Moreno, D. R. Perez, A.S. Gonzalez-Reiche and B.S. Stewart. Influenza A (H1N1)pdm09 virus infection in marine mammals in California. Emerg Microb Infect (Nature). doi:10.1038/emi.2013

DeLong, R.L., G.A. Antonelis, C.W. Oliver, B.S. Stewart, M.C. Lowry, and P.K. Yochem. El Nino on several population parameters and diet of California sea lions on the California Channel Islands. Pp. 167-172. In: F. Trillmich and K. Ono (eds.). Pinnipeds and El Nino: responses to environmental stress. Springer-Verlag, Berlin, 1991.

Leatherwood, S. with G.A. Antonelis, Jr. and D.K. Odell. Population Growth and Censuses of the Northern Elephant Seal, Mirounga angustirostris, on the California Channel Islands, 1958-1978. Fishery Bulletin (US). 79 (3): 562-567. 1981.

Lowry, M.S., Stewart, B.S., Heath, C.B., Yochem, P.K., and Francis, J.F. Seasonal and annual variability in the diet of California sea lions, Zalophus californianus, at San Nicolas Island, California, from 1981 through 1986. U.S. Fish. Bull. 89:331-336. 1990

Rivera, R., H.H. Nollens, S. Venn-Watson, F.M.D. Guilland and J.F. X. Wellehan, Jr. Characterization of phylogenetically diverse astroviruses of marine mammals. Journal of General Virology. 91: 266-173. 2010.

Rivera, R., R. Robles-Sikisaka, E.M. Hoffman, B.A. Stacy, E.D. Jensen, H.H. Nollens and J.F.X. Wellehan, Jr. Characterization of a novel papillomavirus species (ZcPV1) from two California sea lions (Zalophus californianus). Vet Microbiology. 155:257-266.

Stewart B.S., Yochem, P.K. Entanglement of pinnipeds in synthetic debris and fishing net and line fragments at San Nicolas and San Miguel islands, California, 1978-1986. Mar. Pollut. Bull. 18:. 1987.

Stewart, B. S., Antonelis, G.A., and Yochem, P.K. Abundance of harbor seals at San Miguel Island California, 1927 through 1985. Bull S. Calif. Acad. Sci. 87:39-43. 1988.

Stewart, B.S. and DeLong, R.L. Black shouldered kite and northern goshawk interactions with peregrine falcons at San Miguel Island, California. Western Birds. 15:187-188. 1985.

Stewart, B.S. Diurnal hauling patterns of harbor seals on San Miguel Island, California. J. Wildl. Manage. 48:1459-1461. 1985.

Stewart, B.S. The Guadalupe Fur Seal (Arctocephalus townsendi) on San Nicolas Island, California. Bull. Southern California Acad. Sci. 80(3): 134-136. 1981.

Stewart, B.S. Yochem, P.K., DeLong, R.L., and Antonelis, G.A.. Interactions between Guadalupe fur seals and California sea lions at San Nicolas and San Miguel islands, California. NOAA Tech. Rept., NMFS. 51:103-106. 1987.

Stewart, B.S., and P.K. Yochem. Entanglement of pinnipeds in net and line fragments and other debris in the Southern California Bight. NOAA Tech. Memo NMFS, NOSS-TM-NMFSSWFC. 54:315-325. 1985.

Stewart, B.S., and P.K. Yochem. Northern elephant seals breeding at Santa Rosa Island, California. Journal of Mammalogy. 67:402-403. 1986.

Stewart, B.S., and P.K. Yochem. Northern elephant seals on the southern California Channel Islands and El Nino. Pp. 234-243.  In: F. Trillmich and K. Ono (eds.). Pinnipeds and El Nino: responses to environmental stress. Springer-Verlag, Berlin. 1991.

Stewart, B.S., and P.K. Yochem. Seasonal Abundance of pinnipeds at San Nicolas Island, California,1980-1982. Bulletin of the Southern California Academy of Sciences. 83:121-132. 1984.

Stewart, B.S., and Yochem, P.K. Northern elephant seals breeding at Santa Rosa Island, California. J. Mamm. 67:402-403. 1986.

Stewart, B.S., and Yochem, P.K. Seasonal abundance of pinnipeds at San Nicolas Island, California, 1980-1982. Bull. S. Calif. Acad. Sci. 83:121-132. 1985.

Stewart, B.S., G.A. Antonelis, R.L. DeLong, and P.K. Yochem. Abundance of harbor seals at San Miguel Island, California, 1927 through 1985. Bulletin of the Southern California Academy of Sciences. 87:39-43. 1988.

Stewart, B.S., P.K. Yochem, R.L. DeLong, and G.A. Antonelis. Interactions between Guadalupe fur-seals and California sea lions at San Nicolas and San Miguel Islands, California. NOAA Tech. Rept. NMFS. 51:103-106. 1987.

Stewart, B.S., P.K. Yochem. Entanglement of pinnipeds in synthetic debris and fishing net an line fragments at San Nicolas and San Miguel Islands, California, 1978-1986. Marine Pollution Bulletin. 18:336-339. 1987.

Stewart, B.S.. Behavioral response of northern elephant seals (Mirounga angustirostris) and California sea lions (Zalophus californianus) on San Nicholas Island to loud impulse noise. J. Acoust. Soc. Am. Suppl. 70:584. 1981.

VanBlaricom, G.R., and Stewart, B.S. Consumption of pelagic red crabs by black abalone at San Nicolas and San Miguel islands,California. Veliger. 28:328-329. 1986.

Wellehan, J.R., Jr F. Yu, S.K. Venn-Watson, E.D. Jensen, C.R. Smith, W.G. Farmerie and H.H. Nollens. Characterization of San Miguel sea lion virus populations using prosequencing-based methods. Infection, Genetics and Evolution. 10:254-260. 2010.

Yochem, P.K., Stewart, B.S., DeLong, R.L., and DeMaster, D.P. Diel hauling patterns and site fidelity of harbor seals (Phoca vitulina richardsi) at San Miguel Island, California, in autumn. Marine Mammal Science. 3:323-332. 1987.