Population Dynamics of Brown Bears after the EXXON VALDEZ Oil Spill. EXXON VALDEZ211 Oil Spill State/Federal Natural Resource Damage Assessment Final Report 211 (Terrestrial Mammal Study Number 4). Final Report

摘要

We estimated survival and reproductive rates of brown bears (Ursus arctos) on the211u001ecoast of Katmai National Park, Alaska, during 1989-95 to assess effects of the 211u001e1989 Exxon Valdez oil spill. Fifteen percent of fecal samples (n=27) from brown 211u001ebears captured in 1989 contained hydrocarbons indicative of exposure to crude 211u001eoil. Females captured in 1989 and 1990 were divided into 2 grups: 12 with 211u001emultiannual relocations that included oiled coastline, and 21 that used unoiled 211u001eareas. Survival rates during 1989-91 were not different (P>0.90) between females 211u001efrom oiled versus unoiled areas. Based on the assumption that the availability 211u001eand toxicity of oil was negligible by 1992, we also compared survival rates of 211u001eboth groups during 1989-91 with 1992-95 and observed no difference (P>0.40). 211u001eRecruitment rates during 1989-95 were not different (P=0.12) between females from 211u001eoiled and unoiled areas. Finite growth rates for the 2 groups suggested both were 211u001estable (lambda=1.003 and 1.014, respectively, for bears using oiled and unoiled 211u001eareas).