. . . Pacific Marine Mammals 



106 



California Sea Lion 



The California sea lion has three subspe- 

 cies living on the (J.S. west coast and Brit- 

 ish Columbia, in the Galapagos Islands, 

 and in Japan. Between Mexico and British 

 Columbia the population, about 157,000 

 animals, has grown about 6%/year since 

 the 1970's (Fig. 23-5). Annual production 



of 16,000-17,000 pups on the California 

 Channel Islands in 1986 corresponds to a 

 population size of about 87,000 animals. 

 The California population in 1982 (prior to 

 the 1982-83 El Nino warm water intrusion) 

 was thought to be near or slightly below the 

 lower end of its optimum population. 



Figure 23-5.— California sea lion 

 pup counts on the Channel 



Islands, 1971-86. 



Harbor Seal 



The Pacific harbor seal ranges from Mexico There are no reliable estimates for Alaska, 



to Japan, and populations south of Alaska 

 are thought to be increasing. California's 

 minimum population of 20, 1 90 is probably 

 below optimum. The population in Wash- 

 ington and Oregon is about 10,000-15,000. 



but on Tugidak Island the population has 

 declined more than 60% since the early 

 1970's. If this is typical, then the Alaska 

 population is depleted and below optimum 

 levels. 



Hawaiian Monk Seal 



Considered endangered under the ESA, 

 the monk seal is limited to the small islands 

 and atolls of the 1,100-mile Hawaiian Ar- 

 chipelago. The total population is about 

 1,500 animals, a 60% decline since 1958. 

 The monk seals at French Frigate Shoals 

 have increased a bit recently. Average 



counts of the five major breeding sites 

 increased from 468 to 639 during 1 983-87 

 but dropped to 546 in 1990. Production 

 increased during 1983-88 but dropped 

 23% in 1990 from the 1983-88 average 

 (Fig. 23-6). 



