Johansson et at: Seasonal distribution and environmental associations of larval and juvenile Sebastes spp. 
271 
Table 1 
Correlation matrix of average monthly values for temperature (T) and salinity (S) at 
the sea surface (1m) and the depth of 30 m at sampling stations and for large-scale 
environmental indices off Oregon and Washington during 2005-2008. Pearson’s corre¬ 
lation coefficients appear below and associated P-values are given above the diagonal. 
The environmental indices include the Upwelling Index (UI) measured off Oregon and 
Washington and the Pacific Decadal Oscillation (PDO) and North Pacific Gyre Oscillation 
(NPGO) indices. Bold values indicate significant correlations (P<0.05). SST=sea-surface 
temperature; SSS=sea-surface salinity. 
SST 
SSS 
30-m T 
30-m S 
UI 
PDO 
NPGO 
SST 
_ 
0.645 
0.155 
0.880 
0.703 
0.160 
0.921 
SSS 
0.12 
- 
0.498 
0.011 
0.758 
0.149 
0.850 
30-m T 
0.35 
0.17 
- 
0.621 
0.827 
0.137 
0.003 
30-m S 
0.04 
0.58 
0.13 
- 
0.599 
0.337 
0.283 
UI 
-0.10 
0.08 
0.06 
0.13 
- 
0.366 
0.112 
PDO 
0.35 
-0.35 
-0.36 
-0.24 
0.23 
- 
0.101 
NPGO 
0.03 
-0.05 
-0.66 
-0.27 
-0.39 
-0.40 
- 
signed to individual species versus the multispecies 
complex or unidentified. The WEVZ complex accounted 
for 58% of the high confidence, and 59% of the low-con¬ 
fidence data sets, respectively. Because the differences 
between sets were mainly differences of proportion 
rather than differences of identity, we chose to perform 
environmental analyses combining and using both high 
and low-confidence identification results. 
There was some overlap between species identified 
by using morphological versus molecular techniques, 
with 12 species identified in both data sets (Fig. 2). 
However, both approaches also identified species that 
were not identified with the other method. Five spe¬ 
cies, the brown rockfish, Puget Sound rockfish, chili- 
pepper ( S. goodei), grass rockfish (S. rastrelliger), and 
pygmy rockfish, were identified only by visual means, 
whereas 12 species were identified only with the molec¬ 
ular technique (Fig. 2). Thus, the combined approach 
allowed us to identify a total of 29 species in our data 
set, plus those samples identified as belonging to the 
WEVZ complex. 
Environmental data 
During the 4 years of our study (2005-2008), ocean 
conditions during May-October off Oregon and Wash¬ 
ington varied in terms of temperature, salinity, and up- 
welling intensity (Suppl. Fig. 4) (online only). Cooler av¬ 
erage SST with low variation occurred in 2005 (13.9°C 
[standard deviation (SD) 1.7]) and 2006 (14.1°C [SD 
1.3]) than in 2007 and 2008 (16.1°C [SD 2.0] and 14.2°C 
[SD 1.9], respectively). Warmest SST were measured 
during June-September 2007. At 30-m depth, warm¬ 
est temperatures occurred in 2005, a year considered 
anomalous owing to delayed upwelling (Barth et al., 
2007). Although the start of upwelling was delayed in 
2005, once initiated in mid-July, it was strong and per¬ 
sistent, leading to cross-shelf transport of surface wa¬ 
ters. Upwelling was strongest during June-August in 
2006, which likely impacted offshore larval dispersal. 
Salinity varied little at 30 m during the study, but at 
the surface, freshwater input from the Columbia River 
was most detectable during May-June 2005, when up¬ 
welling was delayed. 
Large-scale indices (PDO and NPGO) displayed val¬ 
ues considered more favorable for productivity (more 
negative PDO and more positive NPGO; Chenillat et 
al., 2012; Sydeman et al., 2014) in the California Cur¬ 
rent system during 2007-2008 than during 2005-2006, 
reflected in the highest rockfish density occurring dur¬ 
ing 2007 and 2008 (Suppl. Fig. 5) (online only). In 2008, 
PDO values were the most negative and NPGO val¬ 
ues the most positive throughout the entire sampling 
period (May-October), indicating that cool productive 
ocean conditions, coupled with less cross-shelf trans¬ 
port than in 2005 and 2006, were favorable for rockfish 
prerecruits in 2008. On average, total catches during 
2007-2008 (59,779 rockfish) were >3 times larger than 
catches during 2005-2006 (18,628 rockfish). Effort was 
similar during the 2 time periods (129 hauls during 
2005-2006 and 142 hauls during 2007-2008). Highest 
densities of late-larval and juvenile rockfish (identified 
and unidentified) were sampled in August and Septem¬ 
ber of all years. Ten species/complexes accounted for 
>80% of the genetically identified rockfish over the en¬ 
tire study period (Suppl. Fig. 6) (online only). 
Correlations between mean monthly temperature, 
salinity, and the large-scale environmental indices 
were low (coefficient of determination [r 2 ]=0.002- 
0.436); therefore all were retained for inclusion in the 
community analysis (Table 1). Correlation coefficients 
between salinity at the surface and at 30-m depth were 
positively and significantly correlated (coefficient of 
correlation [r]=0.58, P=0.011) and negatively correlated 
