FISHERY BULLETIN: VOL. 81. NO. 3 



that bivalve mollusks are the primary prey (Fay 

 1982). However, because gastrointestinal samples 

 are extremely difficult to relate to a particular feed- 

 ing habitat and walrus feeding has not been observed 

 in the field, present knowledge of foraging behavior 

 largely depends on morphological arguments and ob- 

 servations of captive animals (Fay 1982). We cannot 

 evaluate walrus disturbance of bottom communities 

 from gastrointestinal samples. The diet and feeding 

 method of walrus provide an opportunity to explore 

 their feeding ecology by examining records of forag- 

 ing activity on the sea bottom. 



There are three principal objectives of this 

 paper: 1) To describe the benthic feeding record of 

 the walrus; 2) to demonstrate that the record pro- 

 vides important insights into patterns of searching, 

 capturing, and consuming prey; and 3) to suggest the 

 roles walrus play in structuring soft-bottom com- 

 munities. 



STUDY AREA 



1). The bottom is gently sloping, with extensive flat 

 regions of fine and muddy sand (Sharma 1974). Bot- 

 tom waters are cold (1°-8°C), and temperatures fluc- 

 tuate seasonally (Muench et al. 1981). Water clarity 

 is poor, usually allowing 0.5 to 1.5 m of visibility, but 

 is occasionally 2 to 8 m. Sea ice forms during the fall 

 and persists until late spring or early summer. Fast 

 ice is relatively persistent nearshore, but offshore ice 

 patterns are highly variable, particularly the oc- 

 currence and movement of the pack ice (McNutt 

 1981; Stringer 1981; Ray and Dupre 1981). No ice 

 gouging of bottom sediments or gas cratering occurs 

 in the study area (Larsen et al. 1979). Walrus are 

 strongly associated with sea ice, where they haul out 

 to care for young and to rest, often between foraging 

 activities (Fay 1982). Large numbers of walrus pass 

 through the study area, particularly during the spring 

 northward migration (May- June). Small numbers 

 may be present there during other months as well 

 (Fay 1982; pers. obs.). Bearded seals are also abun- 



All of our observations and sampling were done 

 near Nome, Alaska, in the northern Bering Sea (Fig. 



FIGURE 1. — The major diving stations (large open circles with X in 

 center) and other sites (small closed circles) surveyed by divers in 

 May- June 1981 near Nome, Alaska. Numbered stations refer to 

 nearby areas occupied at different times. 



18m 



502 



