OLIVER ET AL.: GRAY WHALE FEEDING GROUNDS 



total length of several abundant crustaceans and 

 polychaete worms was measured under a compound 

 microscope with an ocular micrometer. Divers also 

 made numerous visual observations in the relatively 

 clear waters (visibility = 1 to 6 m) and collected 

 qualitative samples of plants and animals. 



Benthic invertebrate communities also were sur- 

 veyed in the central portion of the northern Bering 

 Sea and near St. Lawrence Island from 29 June to 10 

 July 1980 (Nerini in press) and the northeastern Ber- 

 ing Sea from May to June 1981 (Fig. 2). Water depths 

 varied from 9 to 40 m and bottom-water visibility was 

 generally low, ranging from 0.5 to 3 m. Bottom sam- 

 ples were taken by divers using scuba. The same 

 techniques used to procure and process infaunal and 

 sediment samples in Baja California were employed 

 in the Bering Sea. 



RESULTS 

 Fecal Material 



Several fecal slicks were observed floating on the 

 surface waters during the two Bering Sea visits. One 



large slick was sampled on 10 July 1980 on the 

 southeastern side of St. Lawrence Island (Fig. 2). 

 This region is a feeding ground for gray whales, and 

 earlier bottom sampling documented extensive crus- 

 tacean communities dominated by the amphipod, Am- 

 pelisca macrocephala (Stoker 1978, 1981). Although 

 A. macrocephala was abundant in the fecal sam- 

 ple (Table 1) and in our bottom samples (see sec- 

 tion on Infaunal Prey), a group of large prey, includ- 

 ing 1 species of gammaroid and talitroid amphipods 

 (Table 1), did not occur in any of the bottom cores 

 taken in 1980 or 1981 (core number = 156). Gam- 



TABLE 1. — Prey items in a gray whale fecal slick collect- 

 ed from the sea surface near St. Lawrence Island, Bering 

 Sea. From triplicate 1,000 ml subsamples. 



Size (mm) 



No./I.OOO ml 



Amphipods 

 Gammaroids (6 species) 

 Ampeltsca macrocephala 

 Talitroids (2 species) 

 Talitroids (2 species) 

 Calhopius sp. 

 Ischyrocerus sp. 



tsopods 

 Idotheids 



10-50 



72 



I70« 



,6* 



/ 



/ 



/ 



* 





170° 



Gray Whole Dives with pits 



without pits 



Kilometer 

 i 



FIGURE 2. — Diving survey stations in the northern Bering Sea. No walrus excavations occurred outside the walrus feeding ground and no gray 



whale excavations occurred within this area. 



515 



