Zwolinski et al.: Distributions and abundances of Sardinops sagax and other pelagic fishes in the California Current Ecosystem 
115 
stricter! than those of sardine (Fig. 4). 
In 2006, a single stratum comprising 
six transects appeared to encompass 
the entire population of jack mack- 
erel that occupied the southern exten- 
sion of the survey area. In 2008, jack 
mackerel again spanned the southern 
portion of the survey area. In 2010, 
they were distributed off southern and 
central California, but closer inshore 
than in previous years. Similar to 
sardine, the core of the jack mackerel 
distribution in 2010 appeared to be 
off San Francisco and Monterey Bay, 
with lower abundances to the south. 
The trawl catches show Pacific 
mackerel were mainly mixed with 
sardine and jack mackerel (Fig. 1) 
and occurred in lower proportions and 
numbers (Table 1). Their sizes were 
between those of sardine and jack 
mackerel (Table 2). In the three sur- 
veys, Pacific mackerel occupied only a 
fraction of the area occupied by sar- 
dine and jack mackerel and were gen- 
erally found in lower densities (Fig. 5). 
Anchovy and herring occurred in 
isolation in coastal waters off Or- 
egon and Washington, and anchovy 
were mapped north of Monterey Bay 
and in the SCB, indicating a higher 
geographical fidelity than the other 
species (Fig. 1). Both species were 
caught in a small number of samples 
and their catch biomasses were con- 
siderably lower than those for sar- 
dine and jack mackerel (Table 1), ex- 
cept in 2008, when two catches each 
yielded more than 500 kg of anchovy. 
Their apparently low abundances and 
patchy distributions precluded accu- 
rate estimations of their distributions 
and abundances. 
CPS abundances and estimation errors 
Transect-mean biomass densities for 
sardine, jack mackerel, and Pacific 
mackerel showed no intertransect cor- 
relation, thus enabling the use of boot- 
strap to estimate the variance of the 
estimates and respective confidence 
intervals. Sardine were the most abun- 
dant CPS throughout the series, rang- 
ing from 51% to 85% of the estimated 
CPS biomass (Table 3). The CV values 
ranged between 9.2% in 2008, when 
sardine were evenly distributed over 
a relatively small region, to 43.3% in 
2010, when sardine abundance was the 
