63°Nr 



62°N 



5! a N 



60°N 



59°N 



58°N 



57°N 



56°N- 



55°N 



54°N 

 180° 



n i i - 



!78°W 176°W 174°W 172°W !70°W 168°W 166°W 164°W 162°W 160°W 158°W 



Figure 3. — Statistical subdivisions of the Bering Sea study area used for the 1976 spring trawl survey. 



Table 1. — Geographical areas of statistical 

 subdivisions used in the Bering Sea during the 1976 

 spring trawl survey (See Figure 3). 





Area 



Proportion 



Subarea 



(km 1 ) 



of total area 



1 



32,100 



0.243 



2 



62,550 



0.185 



3 Subdivision 3N 



6,550 



0.019 



Subdivision 3S 



73,020 



0.216 



4 Subdivision 4N 



30,960 



0.092 



Subdivision 4S 



72,350 



0.214 



Slope Subdivision 2 Slope 



7,160 



0.021 



Subdivision 3 Slope 



3,240 



0.010 



Total survey area: 



'337,930 



1.000 



The ratio of total 1976 



survey coverage to 



, Q „ 337,930 km 2 

 1975 coverage was ! = 



0.685. 



493,014 km : 



Vessels, Timing of Survey, and Fishing Gear 



Vessels participating in the April-June 1976 demersal trawl 

 survey were the same vessels used to conduct the 1975 baseline 



survey: the commercial stern trawlers Anna Marie and Pat San 

 Marie as well as the NOAA research vessel Miller Freeman (Table 

 2). Additional sampling was conducted by the NOAA research 

 vessel Oregon during May- August 1976. 



Data from the NMFS Crab-Groundfish Survey (Cruise 

 OR-76-02) conducted by the Oregon were used to complete and 

 supplement the spring 1976 trawl survey. Intercomparisons of 

 fishing power were conducted between Oregon and Pat San 

 Marie, 29 May to 9 June 1976. During the period 1 1 June to 4 Ju- 

 iy 1976, the Oregon occupied stations that completed the spring 

 1976 survey grid; these data were included with those from the 

 other three vessels for all analyses of the spring survey grid station 

 results. Other analyses, by month, used all catch data collected by 

 the Oregon during cruise OR-76-02, combined with all the catch 

 data from the other vessels. In addition, all specimen data col- 

 lected during the entire Oregon cruise OR-76-02 were combined 

 with the specimen data from the other vessels for overall 1976 

 analyses. 



The fishing gear used by Miller Freeman, Anna Marie, and Pat 

 San Marie were the same as in the 1975 survey (Table 3). The trawl 

 used by the Oregon had footrope and headrope lengths of ap- 

 proximately 85% those of the gear used by the other vessels. 



