70 USGS/BRD/ITR-2000-0012 



occurred in central California in recent years, numbers 

 remain depressed in Washington. Prey resources have 

 been little studied but were apparently adequate to 

 maintain these populations at higher population levels 

 in 1979-82. Large-scale declines between 1979 and 

 1989 resulted from long-term impacts from 

 anthropogenic factors (i.e., gill-net and oil-spill deaths 

 and human disturbance), coupled with natural factors 

 (i.e., reduced reproductive effort and success associated 

 with severe 1982-83 El Nino, and the 1981 warm water 

 event in Washington). At the same time, climate change 

 has been occurring with a significant warming of coastal 

 waters which also may be affecting murre prey resources 

 (Roemmich and McGowan 1995; Ainley et al. 1996). 

 In central California, climate change has not prevented 

 recent increase in the murre population, but may have 

 reduced the rate of increase (Sydeman et al. 1 997). The 

 apparent overall stability of populations in Oregon and 

 northern California between 1979 and 1989 

 underscored the fact that natural factors alone were not 

 responsible for major declines in central California and 

 Washington (Takekawa et al. 1990; Carter et al. 1995). 

 Washington populations now persist at extremely low 

 levels and are affected by continuing anthropogenic 

 and natural factors, which probably have prevented or 

 slowed recovery. 



The status of common murres in British Columbia 

 is poorly known. The isolated colony at Triangle Island 

 has been present since at least the beginning of the 

 twentieth century. At this colony numbers of breeding 

 murres were relatively stable between 1982 and 1989. 

 Small colonies on the west coast of Vancouver Island 

 disappeared in the 1970s and 1980s. In the past, most 

 potential breeding islands for murres in British 

 Columbia probably were visited frequently by native 

 people hunting seabirds. Murres on Triangle Island 

 breed largely on inaccessible cliffs far from the coast of 

 Vancouver Island, enabling this colony to coexist with 

 native peoples over extended periods of time. Few 

 Europeans or Canadians settled the outer west coast of 

 Vancouver Island (except during a brief sardine fishery 

 in the 1930s), which suggests that human effects were 

 probably low during the twentieth century. However, 

 mortality from oil spills or gill nets may have impacted 

 these colonies, either during the breeding season (e.g., 

 Barkley Sound; Carter and Sealy 1984) or in wintering 

 areas in Juan de Fuca Strait, Puget Sound, or the Straits 

 of Georgia. 



Acknowledgments 



This chapter has benefitted greatly from detailed 

 reviews and editorial comments of various drafts by D. 

 G. Ainley, D. Bertram, G. V. Byrd, A. J. Gaston, M. P. 



Harris, K. Kilbride, G. J. McChesney, D. N. Nettleship, 

 S. Olson-Edge, M. W. Parker, F. L. Paveglio, J. R. Sauer, 

 S. G. Sealy, J. L. Trapp, and T. S. Zimmerman. 

 Administrative support was provided by B. Bortner, D. 

 L. Orthmeyer, and T. Zimmerman. Assistance with 

 preparation of figures and tables were provided by M. 

 Anderson, P. J. Capitolo, J. Daugherty, J. Friday, C. 

 Gregory, G. J. McChesney, D. L. Orthmeyer, and W. Perry. 



In California, funding and support for murre colony 

 surveys and aerial photograph counting from 1985 to 

 1995 were provided by USFWS, Humboldt State 

 University, U.S. Geological Survey (Western Ecological 

 Research Center), California Department of Fish and 

 Game (Office of Spill Prevention and Response and Air 

 Services), Minerals Management Service, U.S. Navy, 

 U.S. Department of Justice, Point Reyes National 

 Seashore, Apex Houston Trustee Council, and Point 

 Reyes Bird Observatory. Administrative assistance was 

 provided by D. G. Ainley, S. Allen, R. Coleman, D. S. 

 Gilmer, R. T. Golightly, J. Hamby, L. Heitz, R. Helm, R. 

 Johnson, T. W. Keeney, P. R. Kelly, V. Lee, D. Lollock, 

 D. L. Orthmeyer, M. W. Parker, M. O. Pierson, G. Reetz, 

 W. J. Sydeman, E. Ueber, and D. Welsh. Aerial surveys 

 were conducted in the Gulf of the Farallones and 

 Monterey Bay National Marine Sanctuaries in 1993- 

 95 under permit numbers GFNMS/MBNMS 04-93, 

 02-94, and 04-95, with assistance by H. M. Golde, T. 

 Jackson, S. Kathey, J. Roletto, and E. Ueber. Aerial 

 surveys were conducted in the Channel Islands National 

 Marine Sanctuary in 1991-95 under permit numbers 

 CINMS 02-91, 04-92, 05-93, 02-94, 01-95, with 

 assistance by M. Crosby, S. Jameson, J. A. Miller, J. 

 Morris, J. A. Uravitch, and C. Wahle. Significant 

 assistance with surveys or photograph counting were 

 provided by L. Accurso-Vicenzio, P. J. Capitolo, T. E. 

 Harvey, D. L. Jaques-Strong, D. L. Jory-Carter, R. W. 

 Lowe, G. J. McChesney, W. R. Mclver, E. Nelson, L. K. 

 Ochikubo, M. W. Parker, C. S. Strong, and D. L. 

 Whitworth. Flights were conducted by Aspen 

 Helicopters (Camarillo, California), California 

 Department of Fish and Game (Air Services; Sacramento, 

 California), and Northern Air Services (Eureka, 

 California). We also greatly appreciate earlier efforts in 

 1979-82 to survey murre colonies with aerial 

 photography in California by K. T. Briggs, A. R. 

 DeGange, G. S. Lester, D. B. Lewis, J. W. Nelson, A. L. 

 Sowls, and W. B. Tyler. We lament the tragic death of J. 

 M. Drust, who piloted many aerial photographic surveys 

 of murre and other seabird colonies in California in 

 1991-95. 



Funding and support for murre colony surveys and 

 aerial photograph counting in Oregon from 1988 to 



