THE SEA OTTER IN THE EASTERN PACIFIC OCEAN 123 



rock or against another clam resting on the otter's chest (fig. 60). 

 It is thus inferred that clams which are buried are not dug from 

 the bottom. 



In the Bering Sea on 8 and 10 July 1960, one adult male and 

 two adult female otters and two pups were taken 31/2 miles off the 

 north shore of Unimak Island in a depth of 15 fathoms and 9 miles 

 north of the Alaska Peninsula in 20 fathoms. The food habits of 

 these individuals are of particular interest because no other 

 stomach specimens of otters which habitually remain offshore are 

 available. The foods found in three of the stomachs are shown in 

 table 15. All food items (clams, crabs, and a hexagrammid fish) 

 are benthic forms. This indicates that here, as in other areas, the 

 sea otter is predominantly a bottom feeder (see Diving). The lack 

 of feces on the beaches of nearby Amak Island in July 1961 and 

 1963 indicates that otters in this area seldom come ashore. 



Fecal Analyses 



studies of sea otter food habits prior to 1962 were based 

 primarily on analyses of fecal remains (Williams, 1938; Murie, 

 1940; 1959; Jones, 1951). All of these studies indicated that the 

 sea urchin was the dominant food species. 



About 95 percent of 422 fecal samples I examined at Amchitka 

 contained sea urchin remains (table 16). Stomach examinations, 

 however, as well as other studies discussed elsewhere (see Rela- 

 tive Values of Sea Otter Foods), indicate strongly that mollusks 

 and fish are essential foods and that in some areas sea urchins 

 may be of relatively minor importance and then primarily during 

 their season of reproduction. 



The examination of feces may contribute certain qualitative 



Table 15. — Stomach contents of three sea otters taken in 15-20 fathoms of 



water in the Bering Sea 



Specimen and food item 



Volume 

 (milliliters) 



Individual 



Adult female (KWK 60-16) : 







Clinocardium cUiatum 



75 



ca. 4 



Musculus sp.? ... _ 



trace 



? 



Surf clam (Spisula alaskanat) 



50 



1 



Fish (Hexagrammos sp.?) 



125 



1 



Pup (KWK 60-18): 







Clam, unidentified 



20 



ca. 4 



Milk curd 



10 





Adult female (KWK 60-19) : i 







Clam {Serripes groenlandicus) 



427 



ca. 20 



Tanner crab (Chionecetes bairdi) - - 



48 



1 



Hermit crab (Pagurus sp.?) 



150 



several 



Crab, unidentified 



trace 





Musculus niger 



trace 





1 Both stomach and intestinal contents included. 



