highest values of prhiiary productivity ever measured in the 

 World Ocean. Fuel for this production center is provided by 

 Bering Shelf water. The water mass transits Bering Strait 

 (where it becomes combined with the Anadyr Current water 

 mass; see Coachman et al.. 1975) and circulates 

 counterclockwise around Kotzebue Sound following the 

 bathymetry (cf. Fig. 1). It still contains, in spite of high 

 utilization upstream, considerable nutrients (e.g., -10 |i g-at 

 NO,/l). 



The cruise of the Akademik Korolev expanded the studies 

 to the west as far as Kolyuchin Bay. The most important 

 finding was another center of production in addition to that 

 southwest of Pt. Hope (Fig. 14), which was associated with an 

 entirely different water mass. The maximum observed salinity 

 of Bering Shelf/ Anadyr Current water in 1 988 was <33, while 

 the salinities of the water of the center off Kolyuchin were up 

 to 33.6 (Fig. 14. lower). At this time the Siberian Coastal 

 Current did not extend all the way to Bering Strait, as 

 demonstrated in the salinity distribution (Fig. 14, lower). The 

 values >32. 9 stopped about 1 00 km short ofthe strait; apparently 

 the current turns east and northeast, closing a gyre with the 

 Bering Shelf water flow to the northwest, southwest of 

 Pt. Hope (cf. Fig. 2). There are times, however, when the 

 Siberian Coastal Current does reach to Bering Strait; Ratmanov 

 (1937b) documented penetration of Siberian Coastal water 

 into the strait in 1933. 



Fig. 14. Average chloroptiyll biomass (upper) and maximum S in the water 

 column (lower) in the southeastern Chukchi Sea, Korolev data, 

 August 1988. Note high chlorophyll off Kotyuchin Bay in addition 

 to the center southwest of Pt. Hope, associated with water with higher 

 salinity than any entering through Bering Strait. 



Thus, the full extent ofthe production area ofthe northern 

 Bering Sea ecosystem in the Chukchi Sea is unknown. It is 

 clearly much larger than previously envisioned. It is fueled by 

 two different water masses — the Bering Shelf water from the 

 south entering directly through Bering Strait, and a Siberian 



Coastal water associated with the Siberian Coastal Current. 

 Prime questions are the source and extent ofthe latter. Few data 

 are available to help search for the source; the best are from the 

 cruise of the USCGC Norihwliul in 1963 (US Coast Guard 

 Oceanographic Unit, 1965). Figure 15 plots the salinities 

 (upper) and nitrates (lower), averaged for the water columns 

 >20 ni, from these data for the Chukchi Sea and Long Strait. 

 The distributions in August 1963 appear to be the saine as in 

 1988. A water mass with salinities greater than any coming 

 into the system from the south follow the Siberian coast. There 

 is a focal point for this water near Wrangel Island; T/S analysis 

 ( Fig. 16) shows the water mass is not extant in the East-Siberian 

 Sea to the west, but in fact shows the highest salinities at the 

 stations in Long Strait, close to Wrangel Island. High nutrient 

 concentrations are associated with this water; it is obviously 

 this water that is responsible for the second region of production 

 in the Chukchi Sea part ofthe ecosystem. The apparent source 

 of this water in the vicinity of Wrangel Island is confirmed by 

 sketchy data from three other cruises (Fig. 17): the Maud in 

 1922 (Sverdrup, 1929), Northwind in 1962 (US Coast Guard 

 Oceanographic Unit, \%A).imdOshoru Maru'm 1972 (Faculty 

 of Fisheries, 1974). It appears that the whole area east of 

 Wrangel Island shows evidence of this high salinity water 

 mass. 



MAXlMUf^ S in water column 

 NORTHWIND 8-16 AUG 1963 



180° 



175° 



170° 



Fig. LS. Maximum S (upper) and nitrate concentration (lower) from the 

 Nonhwiiid. August 1963. The high S water has high nitrates, and 

 seems to he coming from the vicinity of Wrangel Island. 



25 



