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Fishery Bulletin 92(3), 1994 



Rathjen, 1965). Recruitment fluctuations of petrale 

 sole appear to be strongly related to environmental 

 factors ( Ketchen and Forrester, 1966). Ketchen(1956) 

 demonstrated a positive correlation between winter 

 sea surface temperature and recruitment of petrale 

 sole off British Columbia from the middle 1940s to 

 the middle 1950s. In the same area, Ketchen and 

 Forrester ( 1966) postulated that warmer sea surface 

 temperatures and onshore transport of pelagic early 

 life stages could favor recruitment of this species. 



Two central spawning areas of petrale sole, Heceta 

 Bank and Willapa Deep, are located off Oregon and 

 Washington (Fig. 1). Petrale sole spawn from late 

 fall to early spring at depths of about 300-450 m 

 (Cleaver, 1949; Harry, 1959; DiDonato and Pasquale, 

 1970; Pedersen, 1975). The incubation period of 

 newly fertilized eggs ranges from about 6 to 13 days 

 (Alderdice and Forrester, 1971). The eggs and yolk- 

 sac larvae are stenohaline and stenothermal 

 (Alderdice and Forrester, 1971). Development of pe- 

 lagic eggs and larvae occurs mainly from winter to 

 spring, followed by the presettlement and 

 postsettlement juvenile stages from summer to fall 

 respectively (Fig. 2). Although petrale sole larvae 



Figure 1 



Location of Willapa Deep and Heceta Bank spawning 

 grounds of petrale sole, Eopsetta jordani , in Pacific States 

 Marine Fisheries Commission areas 3A and 2B. Spawn- 

 ing areas are located nearly 50 km offshore (modified from 

 Pedersen, 1975). 



I\\\l ESTIMATED ABUNDANCE PEAK OF EGGS AND LARVAE 

 [ | OBSERVED STAGES OFF OREGON 



I INFEHRED DURATION OF STAGES OFF OREGON-WASHINGTON 





K\M 



C 



K\M 



JUVENILE (PHE-SETTLEUENTI [ 



JUVENILE (POST. SETTLEMENT! 



D J F 



WINTER 



M A M 

 SPRING 



SON 

 FALL 



Figure 2 



Estimated duration of life stages of petrale sole, 

 Eopsetta jordani, off Oregon and Washington from 

 the beginning of the spawning period to the time in 

 which most age-0 juveniles are found settled in the 

 inner continental shelf. The inferred temporal oc- 

 currence of life stages was based on the reported 

 duration of spawning, incubation period and pres- 

 ence of presettlement and postsettlement juveniles 

 in the Northeast Pacific Ocean (based on Cleaver, 

 1949; Harry, 1959; Best, 1963; Porter, 1964; Ketchen 

 and Forrester, 1966; Alderdice and Forrester, 1971; 

 Gregory and Jow, 1976; and Pearcy et al., 1977). 



have been found from 2 to 120 km offshore, Pearcy 

 et al. ( 1977) collected nearly 50% of them 83-120 

 km offshore. However, postsettlement juveniles 

 have only been found at 18-90 m depth in the in- 

 ner continental shelf (Ketchen and Forrester, 1966; 

 Gregory and Jow, 1976; Pearcy et al., 1977). 



The recruitment patterns of petrale sole off Or- 

 egon and Washington demonstrated consecutive 

 series of cohorts alternating between below aver- 

 age (weak) YCS and above average (strong) YCS 

 over the base period 1958-77 (Castillo, 1992). Pos- 

 sible causes for such recruitment variations have 

 not yet been studied. Our objectives were to de- 

 termine 1) if spawning biomass of petrale sole is 

 correlated with YCS, 2) if YCS fluctuations are 

 associated with selected environmental factors, 

 and 3) the percentage of YCS variation explained 

 by environmental factors. 



Data and methods 



We selected two locations off Oregon and Wash- 

 ington to investigate the effect of environmental 

 factors on YCS of petrale sole: Pacific States Ma- 

 rine Fisheries Commission 3 areas 2B (42° 50'N- 

 44°18'N)and3A(45"46 , N-47"20'N)(Fig. 1). Indi- 



Named Pacific Marine Fisheries Commission ( PMFC I areas 

 until 1990. 



