162 
Fishery Bulletin 95(1), 1997 
124°30'W 124°00'W 
Figure 1 
The study area along the southern Washington coast. Shown are subsystem 
boundaries, nearshore transect lines, trawl stations (filled circles), and 
stratum numbers (open circles). Dashed lines indicate survey stratum 
boundaries. 
larval abundance may indicate poor year- 
class strength, but high larval abundance will 
not guarantee a strong year class (Bailey and 
Spring, 1992; Bradford, 1992). Survival dur- 
ing the juvenile stage is critical to year-class 
success. On the basis of simulation, Bradford 
(1992) concluded that correlation between 
recruitment and abundance at early life 
stages increases monotonically with age, es- 
pecially during the first 100 days of life, be- 
cause variation in survival weakens the re- 
lationship between recruitment and abun- 
dance of early life stages. Although monthly 
or annual instantaneous mortality is usually 
higher during the larval stage than that at 
the juvenile stage, the cumulative mortality 
might be higher, and more variable, during 
the juvenile stage because it usually lasts 
much longer. Therefore any variation in mor- 
tality at this stage would induce much greater 
variation in recruitment. 
English sole spawn in offshore areas. Tim- 
ing of spawning is variable and duration of the 
spawning period is protracted (August to May, 
Shi, 1994). The egg and larval stages last from 
two to two-and-a-half months, and survival and 
transport of eggs and larvae are dependent on 
oceanographic conditions (Boehlert and Mundy, 
1987, 1988; Shi, 1994). Once metamorphosis 
and benthic settlement have occurred, English 
sole actively seek out estuarine nursery areas, 
and oceanographic influence becomes less im- 
portant. Analyses of tagging data, distribution 
of adults, available spawning habitat, and egg 
distribution (Shi, 1994) suggest that the Grays 
Harbor and Willapa Bay estuaries serve as 
nursery areas for English sole that spawn as 
far south as central Oregon. 
This study summarizes results from a series of 
trawl surveys of Grays Harbor, Willapa Bay, and the 
adjacent nearshore, 1985-88. Previous work (Gun- 
derson et al., 1990; Shi et al., 1995) has shown that 
these estuaries provide critical nursery habitat for ju- 
venile English sole during their first year of life. 
The abundance of 0 + English sole in our study area 
(Fig. 1) was relatively stable during September, show- 
ing only a threefold difference during 1985-88, de- 
spite great variation in settlement in May (Shi et 
ah, 1995). If survival is density dependent, then den- 
sity could function to stabilize recruitment. In this 
paper, growth and survival rates will be estimated 
by using data from field surveys, and we will inves- 
tigate statistically the effects of population size and 
ambient temperature on the growth and survival of 
juvenile English sole. 
Methods 
Study area and field methods 
Grays Harbor (8,545 ha) and Willapa Bay (11,200 
ha) are two major Washington coastal estuaries char- 
acterized by numerous channels, sandflats, and eel- 
grass beds that provide excellent habitat for 0 + En- 
glish sole. The nearshore portion of the study area is 
bounded to the north at 47°15'N, and to the south at 
about 46°30’N, and extends from the shoreline sea- 
ward to 60 m. It encompasses an area of nearly 
146,600 ha. 
A stratified random trawl survey was performed 
to estimate population sizes for English sole in both 
estuaries (Fig. 1) with the area-swept method: P - Ad , 
where P = population size, A = area of survey stra- 
tum (ha), and d = mean density (no. of fish caught/ 
