ground. Consequently, the counts obtained 

 must always be considered minimum. 



Timing of a survey influences the results 

 markedly. For example, during a survey of 

 the Copper River Flats in October 1957, 

 only 30 to 40 seals were seen, whereas sev- 

 eral thousand were seen there during the 

 fishing season. This survey may have been an 

 exceptional observation because the presence 

 of large numbers of harbor seals in the fall 

 was established during a seal control pro- 

 gram in 1951 (Alaska Fisheries Board and 

 Alaska Department of Fisheries, 1952, p. 44- 

 45). 



Since seals are widely scattered and may 

 haul out in small numbers at numerous loca- 

 tions, a complete survey is both a long and 

 arduous task, as well as an expensive one. 

 Furthermore, all that is known about the 

 migrations of the seals is that they may be 

 frequent and extensive. 



The results of the surveys are summarized 

 in appendix table 1. The counts given should 

 not be considered as complete survey esti- 

 mates; they only indicate the number of harbor 



seals that were seen in the indicated areas 

 at the time of the surveys. 



The Trinity Islands south of Kodiak Island 

 accounted for most of the seals during all 

 surveys, although there were seasonal varia- 

 tions in numbers similar to those observed 

 on sea lion rookeries. In both 1956 and 1957, 

 the December survey of the Trinity Islands 

 showed a marked decline in the number of 

 animals from the fall surveys in the same 

 years. A number of reasons may account for 

 the decline. Harbor seals may spread out 

 more along the entire coast during the winter; 

 they may spend a longer time at sea in search 

 of food; or they may migrate to another area 

 during the wintertime. 



Although harbor seals are at times found 

 with sea lions, they are usually at the out- 

 skirts of the main rookery, as was seen at 

 Chernabura Island in 1958.' 



The center of population density as re- 

 vealed by the photographic census lies in the 

 Kodiak Island area. More harbor seals than 

 sea lions were observed in the Chignik district. 



' See footnote 1 on p. 6. 



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