550 
Fishery Bulletin 96(3), I 998 
Table 2 
Summary of AFSC groundfish surveys on the eastern Bering Sea shelf. Tows in which yellowfin sole (YFS, Pleuronectes asper ) 
were captured are noted parenthetically. 
Survey Area 2 Gear 2 
Date 
Bottom 
depth (m) 
Number 
of tows 3 
Number 
of YFS 
measured 
Standard EBS 83-112 
June- Aug 1982 
18-137 
329 (251) 
37,023 
June-Aug 1983 
20-134 
354 (270) 
33,924 
June-Aug 1984 
18-134 
355 (279) 
33,894 
June-Aug 1985 
18-154 
353 (270) 
33,824 
June-Aug 1986 
18-148 
354(251) 
30,470 
June-Aug 1987 
18-112 
342 (235) 
31,241 
June-Aug 1988 
18-130 
353 (249) 
27,121 
June-Aug 1989 
18-110 
354 (236) 
29,510 
June-Aug 1990 
16-126 
352 (247) 
30,491 
June-Aug 1991 
18-119 
351 (248) 
27,985 
June-Aug 1992 
16-152 
336 (231) 
23,626 
June-Aug 1993 
18-163 
355 (243) 
26,647 
June-Aug 1994 
16-113 
355 (257) 
24,420 
June-Aug 1995 
16-154 
356 (249) 
22,111 
June-Aug 1996 
20-114 
355 (247) 
27,190 
Exploratory Kuskokwim Bay 83-112 
June 1988 
13-27 
4(4) 
786 
area 
June 1989 
9-20 
4(4) 
734 
June 1990 
13-29 
2(2) 
408 
June 1991 
13-29 
2(2) 
293 
Togiak Bay area 83-112 
June 1988 
13-29 
5(5) 
1264 
June 1989 
16-27 
5 (5) 
1438 
June 1990 
11-26 
2(2) 
515 
June 1991 
15 
1 (1) 
107 
Nearshore beam trawl Togiak Bay area PSB 
May, 1995 
2-30 
28 (28) 
4134 
1 EBS = eastern Bering Sea shelf area from the Alaska Peninsula north to latitude 62° N. 
2 83-112 = Eastern otter trawl with 25.3 m (83 ft) headrope and 34.2 m (112 ft) footrope PSB 
= plumb-staff beam trawl with a 3.1 m (10 ft) 
aluminum beam 
3 Number in parentheses indicates number of tows in which yellowfin sole were captured. 
surveys (Fig. 2; Table 2). These tows were conducted 
to collect preliminary data on spawning yellowfin 
sole, which were known from commercial trawl re- 
ports to occur in these nearshore areas. Extensive 
survey coverage of this area has been limited owing 
to the shallow bottom depths. 
Nearshore beam-trawl survey A 3. 1-m plumb staff 
beam trawl with specifications detailed in Gunderson 
and Ellis (1986) was used aboard a chartered 9.7-m 
(32-ft) purse-seine or gillnet vessel. This survey suc- 
cessfully sampled a total of 28 stations in the shal- 
low waters of the Togiak Bay area, from 18 May to 
28 May 1995 (Fig. 2; Table 2). Sampling depths 
ranged from 1.8 m nearshore to 30.2 m offshore. Tows 
were made during daylight hours and were less than 
10 min in duration. All yellowfin sole were sexed, 
measured, and assigned a maturity code. For the 
purpose of this examination, maturity was classified 
as either mature or immature. Females were con- 
sidered mature if ovaries were yolked or recently 
spent. Males were considered mature if testes were 
swollen, opaque colored, running with sperm, or re- 
cently spent. 
Analysis 
Yellowfin sole distributions were described in terms 
of catch per unit of effort (CPUE; kg/hectare) for each 
of the 1982-96 AFSC standard surveys. Calculation 
of CPUE followed area-swept methods described by 
Alverson and Pereyra (1969), whereby catch is the 
total weight (kg) of yellowfin sole within a station 
tow and effort is the area (hectare) swept by the path 
of the trawl. Area swept was computed as the prod- 
uct of the distance fished and the effective net-spread 
