. The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder. Oceanography Bering Figure 36-9. Schematic diagram of October distribution of halibut, herring, pollock, and yellowfin sole. (Long dashes indicate probable extension of shelf range; broad Hne indicates ice edge.) ice cover data are available, one can presume that the effects of the wind mixing and subsequent ice cover will quickly dominate any downward diffusion of residual heat in the water column. Both cooling effects will reach depths exceeding 100 m; the former takes place withi
. The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder. Oceanography Bering Figure 36-9. Schematic diagram of October distribution of halibut, herring, pollock, and yellowfin sole. (Long dashes indicate probable extension of shelf range; broad Hne indicates ice edge.) ice cover data are available, one can presume that the effects of the wind mixing and subsequent ice cover will quickly dominate any downward diffusion of residual heat in the water column. Both cooling effects will reach depths exceeding 100 m; the former takes place within a day or so, the amount of cooling depending on water temperatures in the surface layer, and the latter requires one to several weeks. However, it is prolonged ice cover that gradually drives bottom temperatures on the shelf down to — C and the freezing-out of fresh water results in higher salinities. Nevertheless, temperatures of 3-4 C still occur on the bottom at the shelf edge and upper slope. The ice edge in November generally extends from Bristol Bay seaward of Nunivak and St. Lawrence Islands into the western Gulf of Anadyr. By December it extends from outer Bristol Bay past St. Matthew Island to Cape Navarin. Herring and yellowfin sole are believed to reach offshore wintering grounds in November (Fig. 36-10). Herring overwintering in the Norton Sound area under the ice may experience temperatures higher than — C in the deeper areas if wind mixing did not establish neutral stability in the water column before ice cover was formed. Pollock retreat to the 100-m isobath by the end of December; at this time halibut have largely retreated seaward of the 200-m isobath. RESOURCE ENVIRONMENT RELATIONS The life histories of the dominant fish (except for halibut) selected for discussion in this section are quite diverse. Harden Jones (1977) suggests that fish movements can be summarized in the form of trian- gular patterns in which adult fish move between their spawning
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