54 USGS/BRD/ITR-2000-0012 



reduced over a period of time and numbers of murres 

 correspondingly increased. In 1957 the Tillamook Rock 

 lighthouse was decommissioned. In 1980 access was 

 limited under private ownership. In 1993 the USFWS 

 obtained a perpetual conservation agreement for this 

 site and human access during the breeding season was 

 prohibited. Numbers of murres attending this site 

 between 1987 and 1995 far exceeded numbers in the 

 1970s and peaked in 1995 (see Appendix I: Figure 1-31). 

 Human disturbance has occurred regularly at many 

 colonies in Oregon but, to date, this has not resulted in 

 colony abandonments. Recently, disturbances from low- 

 flying aircraft and close approach by boats were well 

 documented at Three Arch Rocks (Lowe 1993). 

 Management actions have now been implemented to 

 reduce the problem at this colony complex but human 

 disturbance at other colonies throughout the Oregon 

 Coast National Wildlife Refuge Complex remains a 

 primary management concern. 



Gill-net fishing has been prohibited in Oregon since 

 the 1940s and no large oil spills have occurred adjacent 

 to colonies before or during the 1988-95 study period. 

 However, death of murres from gill-net fishing and oil 

 spills in Washington and British Columbia undoubtedly 

 included large numbers of murres from Oregon colonies 

 during or after northward movements that occur after 

 colony departure (Manuwal and Carter 2001). Two 

 major oil spill events in Washington (i.e., 1988 

 Nestucca and 1991 Tenyo Maru) killed an estimated 

 30,000 and a range of 3,740-19,559 murres, respectively 

 (Ford et al. 1991 ; Tenyo Maru Oil Spill Natural Resource 

 Trustees 2000). Given the relative size of the common 

 murre populations in Washington and British Columbia 

 prior to and after the Nestucca spill, it is quite likely 

 that a substantial proportion of the birds killed as a 

 result of this event were from Oregon breeding colonies. 

 An assessment of the origin of murres killed in the Tenyo 

 Maru spill indicated that 39-58% of the adult murres 

 killed in the spill were from Washington and the 

 remainder (42-61%) were from Oregon, although a 

 series of assumptions were used to generate this estimate 

 (Warheit 1996). Murre deaths also result from gillnet 

 entanglement in the fall sockeye salmon fishery in Puget 

 Sound, Washington (Pierce et al. 1994). This fishery 

 and associated seabird deaths take place when Oregon 

 birds are typically present (Manuwal and Carter 2001). 

 In 1997, the Washington Department of Fish and 

 Wildlife adopted regulations to reduce seabird deaths 

 in the nontreaty fishery by eliminating early morning 

 (dawn) fishing and requiring net modifications (Melvin 

 et al. 1999). In addition, die-offs of large numbers of 

 chicks after colony departure have been reported for 

 decades in Oregon (Bayer et al. 1991), but the level of 



deaths may have increased since 1990 (R. W. Lowe, 

 unpublished data). 



Along the north and central coasts, predation and 

 disturbance by bald eagles have severely affected 

 breeding murres at some colonies (R. W. Lowe, personal 

 observation). This was first noted in 1994 and continues 

 to increase at colony sites from Tillamook Head to 

 Colony Rock in Newport. The disruption at murre 

 colonies has been concomitant with increased sightings 

 of juvenile bald eagles in this area. Most impacts result 

 from repeated colony disturbance, rather than actual 

 predation. Juvenile eagles often perch within colonies 

 and delay murre egg laying. Disruptions during 

 incubation cause murres to flush, exposing murre eggs 

 to breakage or predation by gulls and corvids. At Bird 

 Rocks at Chapman Point (Colony numbers 219-017 

 and 219-018), continued harassment by eagles 

 throughout the breeding season has resulted in erratic 

 colony attendance and complete breeding failure. 

 Recent effects from various natural and anthropogenic 

 factors have been localized (e.g., eagle or human 

 disturbance at specific colonies) or dispersed among 

 the numerous colonies and large populations (e.g., oil- 

 spill and gill-net deaths). Efforts to further reduce 

 anthropogenic effects are continuing. 



Washington 



Historical Background on Breeding Colonies 

 in Washington, 1905-1978 



The degree to which native people affected murres 

 in western Washington before the early twentieth century 

 is not clear. Despite large populations of native people 

 and the common use of canoes, the inaccessibility of 

 many rocks and islands on the Washington coast may 

 have limited food gathering activities to certain 

 locations. At some larger islands (i.e., Tatoosh Island), 

 occupation by native people probably prevented 

 breeding by murres. Seagull eggs were harvested in June 

 from colonies at Point Grenville and Cape Elizabeth by 

 Quinault native people (Olson 1936;Speichetal. 1987). 

 However, harvesting of gull eggs apparently did not 

 prevent murre breeding at Willoughby Rock in 1906, 

 although gull egg harvesting by Ozette native people 

 may have prevented breeding by murres at White Rock 

 (Dawson 1907). 



In July 1906 and June 1907, most seabird colonies 

 on islands off the outer coast of Washington were 

 surveyed by canoe, and 1,736 murres were counted at 

 seven locations (Dawson 1907, 1908a, 1908b; Dawson 

 and Bowles 1909). Five of these colonies Erin, 

 Grenville Arch, Grenville Pillar or "Radio Stack," 



