136 



NORTH AMERICAN FAUNA 68 



The sea otter was then commercially extinct and nearly extinct 

 as a species. The number of sea otters that were taken during the 

 period of unregulated exploitation is not known because proper 

 records were not kept. Most records are vague concerning where 

 skins came from, except that they came from the New World. 

 Fisher (1940b) states that her summary is not complete but lists 

 records of 359,375 skins taken between 1740 and 1916. Between 

 1745 and 1867, ''260,790 sea otter skins were reported as having 

 been shipped from Alaska" and from 1868 to 1905 the take was 

 107,121 skins (U.S. Bureau of Fisheries, 1906). From 1906 to 



1910, 240 skins are recorded taken by U.S. and Canadian hunters 

 (U.S. Bureau of Fisheries, 1907 through 1911). Thus the total 

 recorded number of skins taken in waters off Alaska, prior to 



1911, was 368,151. Skins taken by hunters of other nationalities 

 are not recorded. Lensink (1960) presents figures and broad esti- 

 mates which place the take of sea otters from Alaska at over 

 906,500 animals. 



POSTULATED SIZE OF ABORIGINAL POPULATION 



From data gathered during recent studies, some idea of the 

 possible take may be postulated. Today it appears that about 

 30,000 sea otters occupy approximately one-fifth of the original 

 lineal coastal range of the sea otter. Some of the presently occupied 

 habitat is of superior quality. Islands contribute more usable 

 habitat than do unbroken continental coastlines. Thus, it is prob- 

 able that the population of sea otters in 1740 may have been no 

 more than five times the present number, probably between 

 100,000 and 150,000 animals. If the annual increment that could 

 be cropped on a sustained yield basis was about 2.5 percent per 

 year (the approximate annual yield of the Pribilof fur seal ( Callor- 

 Mnus ur sinus) herd is 5 percent per year and fur seals normally 

 bear one pup each year; 2 years elapse between sea otter pups), 

 then the take in 170 years could have been between 425,000 and 

 637,500 if cropping had been rational. The killing of sea otters, 

 however, was unregulated and for periods of many years the take 

 was at the expense of the population "capital." Probably certain 

 populations were wiped out during an early part of the exploitation 

 period. Thus the yield over the entire period was less than it would 

 have been if only the annual increment had been taken. Reasoning 

 on this basis, it appears that the probable take of sea otters between 

 1740 and 1911 was less than a million and more likely about a 

 half million animals. 



In the following section, sea otter population studies in Alaska 



