Boldt and Rooper: Abundance, condition, and diet of Sebastes alutus 
283 
A 
Figure 5 
Zooplankton prey consumed by three size classes of juvenile Pacific 
ocean perch ( Sebastes alutus) (<160 mm, <210 mm, and >210 mm fork 
length) collected with a bottom trawl at the north (N) and south (S) 
Samalga Island sites in August and at the north (N) site in June in 
the Aleutian Islands, Alaska. The average numerical (A) and weight 
(B) proportions of hyperiid amphipods, chaetognaths, Limacina ptero- 
pods, larvaceans, euphausiids, large copepods (>2.5 mm), and other 
prey (<5% of prey proportions) are shown. Other prey include small 
copepods (<2.5 mm), barnacle cyprids, crab zoeae, fish, fish eggs, 
insects, larval fish, invertebrate eggs, ostracods, polychaetes, shrimp, 
mysids, and jellyfish. 
juvenile POP abundance was low in the north, where fish 
condition was highest. If the large zooplankton biomass 
at the north site indicates enhanced prey availability to 
juvenile POP, it may help explain the high POP condition 
observed at that site. 
Juvenile POP stomachs sampled in June were more 
than twice as full as those sampled in August at the 
north site, indicating that POP are able to consume 
more than they appeared to consume in August. This 
finding, along with differences in juvenile POP abun- 
dance and in zooplankton biomass between the two 
sample sites in August, may indicate that food limi- 
tation and competition contributed to the observed 
geographic differences in fish condition. In August, 
however, stomach fullness was similar at both sites 
for all size classes, indicating that fish were consum- 
ing similar amounts of food at both sites. Also, the 
proportion of empty stomachs tended to be higher at 
