560 
Fishery Bulletin 96(3), 1998 
retreat determines the timing of inshore yellowfm 
sole migration (Bakkala, 1981), and subsequently the 
timing of spawning, distribution patterns at the time 
of the survey could be affected. Increasing percent- 
ages of spent yellowfm sole during the June 1993 
AFSC survey (Nichol, 1995) indicated that spawn- 
ing activity progresses within the duration of the 
survey. Spring-summer surveys conducted in 
warmer years may intercept higher proportions of 
spent individuals that no longer inhabit the unavail- 
able nearshore spawning areas. 
Interannual variation of yellowfin sole biomass 
estimates within the eastern Bering Sea may be re- 
duced under alternative survey designs (McAllister, 
1995). I recommend the incorporation of additional 
standard stations in nearshore areas, such as the 
exploratory tows made in Togiak and Kuskokwim 
Bays (Fig. 2), and east of Nunivak Island. The addi- 
tion of such stations would likely reduce interannual 
variation of survey biomass estimates as well as pro- 
vide a more accurate representation of the popula- 
tion sex-composition. 
Acknowledgments 
I thank Terry Sample, Gary Walters, Claire Armi- 
stead, Pam Goddard, Bob McConnaughey, and nu- 
merous other AFSC personnel who contributed to the 
AFSC surveys from 1982 to 1996. I also appreciate 
the efforts of Tom Crawford, skipper of the FV 
Crawdad, during the Togiak Bay beam-trawl survey. 
Peter Munro and Steve Syrjala helped with the sta- 
tistical analysis. Dave Somerton, Jay Orr, Gary 
Walters, Gary Stauffer, James Lee, and Gary Duker 
provided valuable comments on early versions of this 
manuscript. David Sampson and two anonymous 
reviewers helped strengthen later versions of the 
manuscript. 
Literature cited 
Alverson, D. L., and W. T. Pereyra. 
1969. Demersal fish explorations in the northeastern Pa- 
cific Ocean: an evaluation of exploratory fishing methods 
and analytical approaches to stock size and yield 
forecasts. J. Fish. Res. Board Can. 26:1985-2001. 
Bakkala, R. G. 
1981. Population characteristics and ecology of yellowfin 
sole. In D. W. Hood and J. A. Calder (eds.). The eastern 
Bering Sea shelf: oceanography and resources, vol. 1, p. 
553-574. U.S. Dep. Commer., NOAA, Off. Mar. Poll. As- 
sess., U.S. Gov. Print Off., Wash., D.C. 
1993. Structure and historical changes in the groundfish 
complex of the eastern Bering Sea. U.S. Dep Commer., 
NOAA Tech. Rep. NMFS 114, 91 p. 
Beverton, R. J. H. 
1964 . Differential catchability of male and female plaice in 
the North Sea and its effect on estimates of stock abun- 
dance. Rapp. P.V. Reun. Cons. Int. Explor. Mer 155:103- 
112 . 
Coachman, L. K. 
1986 . Circulation, water masses, and fluxes on the south- 
eastern Bering Sea shelf. Continental Shelf Res. 5(1/ 
2):23-108. 
Cochran, W. G. 
1977 . Sampling techniques, third ed. John Wiley and 
Sons, Inc., New York, NY, 428 p. 
Efron, B., and R. J. Tibshirani 
1993 . An introduction to the bootstrap. Chapman and 
Hall, New York, NY, 436 p. 
Fadeev, N. S. 
1965 . Comparative outline of the biology of flatfishes in the 
southeastern part of the Bering Sea and condition of their 
resources. Translated by Isr. Prog. Sci. Transl., 1968. In 
P. A. Moiseev (ed.), Soviet fisheries investigations in the 
northeastern Pacific, part 4, p 112-129. [Available from 
U.S. Dep. Commer., Natl. Tech. Inf. Serv., Springfield, VA, 
as TT 67-51206.] 
1970 . Fisheries and biological characteristics of the east- 
ern Bering Sea yellowfin sole. Translated by Isr. Prog. Sci. 
Transl., 1972. In P. A. Moiseev (ed.), Soviet fisheries in- 
vestigations in the northeastern Pacific, part 5, p 332- 
396. [Available from U.S. Dep. Commer., Natl. Tech. Inf. 
Serv., Springfield, VA, as TT 71-50127.) 
Gunderson, D. R. 
1993 . Surveys of fisheries resources. John Wiley & Sons, 
Inc., NY, 248 p. 
Gunderson, D. R., and I. E. Ellis. 
1986 . Development of a plumb staff beam trawl for sam- 
pling demersal fauna. Fish. Res. 4:35-41. 
Hart, J. L. 
1973. Pacific fishes of Canada. Fish. Res. Board Can. Bull. 
180, 740 p. 
Low, L., and R. E. Narita. 
1990 . Condition of groundfish resources in the Bering Sea- 
Aleutian Islands region as assessed in 1988. U.S. Dep. 
Commer., NOAA Tech. Memo. NMFS-F/NWC-178, 224 p. 
McAllister, M. K. 
1995 . Using decision analysis to choose a design for sur- 
veying fisheries resources. Ph.D. diss. Univ. Washington, 
Seattle, WA, 293 p. 
Methot, R. D. 
1990 . Synthesis model: an adaptable framework for analy- 
sis of diverse stock assessment data. Symposium on appli- 
cation of stock assessment techniques to gadoids. Inter- 
national North Pacific Fisheries Commission (INPFC) Bull. 
50:259-277. 
Nichol, D. G. 
1995 . Spawning and maturation of female yellowfin sole in 
the eastern Bering Sea. In Proceedings of the international 
flatfish symposium, October 1994, Anchorage, Alaska, p. 35- 
50. Univ. Alaska, Alaska Sea Grant Rep. 95-04. 
1997 . Effects of geography and bathymetry on growth and 
maturity of yellowfin sole, Pleuronectes asper, in the east- 
ern Bering Sea. Fish Bull. 95(3):494-503. 
Pola, N. B., E. J. Rykiel Jr., and W. E. Grant. 
1985 . Numerical simulation of fish migrations in the east- 
ern Bering Sea. Ecol. Model. 29:327-351. 
SAS Institute Inc. 
1989 . SAS/STAT user’s guide, version 6, fourth ed., vol. 
2. SAS Institute Inc., Cary, NC, 846 p. 
