e) 



b) 



a) 



87 88 



STATIONS 

 89 90 



91 



30 60 90 

 97 98 99 100 101 



20 

 02 



15 

 26 27 28 



30 45 60 

 29 32 33 34 35 



325 430 

 38 39 107 



100 200 300 

 DISTANCE 



400 

 (km) 



490 



Fig. 



Vertical c 

 10 North ( 



ross-sections of chlorophyll (mg/m') arranged from South 

 a to e). Transect location given on Frontispiece. 



the gulf at a depth of 20 to 30 m (Fig. 2b). A cross section from 

 Station 1 3 to .Station 39, from the outer shelf ( 1 50 m) to Anadyr 

 Strait (30 m), reveals high phytoplankton biomass strictly 

 limited to the strait area providing evidence of the influence of 

 nutrient-rich Anadyr water (Fig. 2a). 



Anadyr Sirail 



Data from Anadyr Strait indicate that high integrated 

 chlorophyll values were associated with waters near the 

 Siberian coast at Station 39 ( 193 mg/m-). Values decreased to 

 the east to 23 mg/m- at Station 43 next to St. Lawrence Island 

 (Fig. 1). A cross-section of Anadyr Strait provides another 

 view of the association between phytoplankton stocks and 

 Anadyr water. Chlorophyll concentrations decrease to less 

 than 1.0 mg/m' across the eastern half of the strait (Fig. 2c). 



Chihkov basin 



Stations 87 to 1 07 were in the Chirikov basin (Frontispiece). 

 Data from this area revealed high chlorophyll values on the 

 western side of the basin, suggesting the presence of higher 

 nutrient water (Fig. 1 ). Integrated chlorophyll values as high 

 as 593 mg/m-, at Station 87, were observed close to the Soviet 

 coast. The western side of the basin is characterized by values 

 over 100 mg/m-. Chlorophyll values decrease to the east across 

 the basin. Phytoplankton biomass of less than 50 mg/m- was 

 characteristic of the eastern side of the basin in Alaska Coastal 

 water. The maximum eastward extent of high chlorophyll 

 values was observed in the central part of the basin at Station 

 94 (307 mg/m-). Data from a transect across the central basin, 

 from stations 97 to 102, shows distinct areas of high biomass, 

 one next to the Soviet coast and one in the central part of the 

 basin (Fig. 2d). The western concentration has a subsurface 

 chlorophyll maximum (>3.0 mg/m') at 10 to 15 m while the 

 eastern area has a maximum (>8.0 mg/m') at 20 to 25 m. These 

 two areas of high biomass lose their identity and converge with 

 the water masses flowing toward Bering Strait (Fig. 2e). The 

 highest concentration of chlorophyll in the Chirikov basin was 

 measured at Station 87 the closest station to the Soviet coast. 



Bering Strait 



Bering Strait was surveyed twice. The first transect 

 occupied six stations (76-8 1 ) across the strait while the second 

 transect occupied five of the same stations (82-86), omitting 

 only the westernmost station. Integrated values of chlorophyll 

 indicate the same pattern for both transects (Fig. 1 ). Highest 

 values, up to 619 mg/m- at Station 76, were observed adjacent 

 to the Soviet coast west of Ratmanov Island and the lowest 

 value ( 27 mg/m- at Station 8 1 ) occurred east of Diomede Island 

 near the Alaskan coast. 



During the first passage, the chlorophyll maximum on the 

 western side of the strait (>25 mg/m') was at the surface at 

 Station 76 (Fig. 3a). On the eastern side of the strait there were 

 noconcentrationshigherthan 1.7mg/m'. Although the western 

 side of the strait showed high integrated values throughout the 

 water column, most phytoplankton were close to the Soviet 

 coast. In the second transect a similar pattern existed as in the 

 first with the exception of a subsurface maximum (8.0 mg/m') 

 on the western side at 30 m. Bottom concentrations on the 

 eastern side near Diomede Island appear to match bottom 



125 



