712 



Fishery Bulletin 100(4) 



180 m 



Washington 



47 — 



Northern 

 Oregon 



45 — 



Newport 



\180m 



Pacific 

 Ocean 



44" 



Charleston 



43 



Southern 

 Oregon 



Brookings 



42 



125' 



124° 



I 



Figure 1 



Sampling area for petrale sole (bold-outline polygon) off Newport, Oregon, and areas 

 where winter trawl fishing for petrale sole is concentrated (gray polygons). Also shown 

 is the 180-m depth contour. 



(Sehastes alutus), a shift in the estimated median age of 

 maturity for female fish from 7.5 to 10.5 years decreased 

 the Fji,,. value from 0.110 to 0.076. a decrea.se of 31'/f. Ac- 

 cordingly, the use of potentially biased maturity data from 

 the winter commercial fishery for petrale sole adds to the 

 uncertainty in stock assessments. The accuracy of matu- 

 rity information used in recent petrale sole stock assess- 

 ments is also uncertain because of two additional factors: 

 outmoded data and the blending of samples across space 

 and time (Sampson and Lee.'; Turnock et al.M. Maturity 

 samples are obtained from various locations and times, 

 and are often combined to produce a general relationship 

 for stock assessment purposes. The combined relationship 

 may poorly account for geogi'aphical differences, long-term 



■'' Turnock, J., M. Wilkins, M. Saelcns, and t'. Wood. 199,3. Sta- 

 tus of West Coast petrale sole in 1993. Appendix G. In Status 

 of the Pacific Coast groundfish fishery through 1993 and recom- 

 mended biological catches for 1994: stock assessment and fish- 

 ery evaluation. Pacific Fishery Managemenmt Council, 2130 

 SW Fifth Ave., Suite 224, Portland, OR 97201. 



changes in maturity, or for inadequacies in some samples 

 (e.g. lack of immature fish) (Sampson and Al-Jufaily, 1999) 

 and can result in poorly determined curves that bias and 

 degrade the fit of the combined maturity relationship. The 

 principal objective of our study was to collect maturity 

 data for female petrale sole from the late summer to early 

 fall period and compare them with the maturity data used 

 in recent stock assessments (Sampson and Lee'; Turnock 

 et al.'). Although sampling in late summer and early fall 

 is probably optimal for assessing female maturity in the 

 petrale sole population, some ovaries may be difficult to 

 classify accurately as mature or immature by macroscopic 

 inspection. A second objective of our study was to evaluate 

 female petrale sole maturity by using microscopic exami- 

 nation of stained thin sections and compare these results 

 with those obtained from simple visual inspection. 



The petrale sole maturity data used in recent stock as- 

 sessments have been obtained from the Oregon Depart- 

 ment of Fish and Wildlife's commercial fishery sampling 

 program (Sampson and Lee'; Turnock et al.-^). Potential 



