285 
Abstract .—First ocean-year feeding 
habits were determined for juvenile 
salmon (Oncorhynchus spp.) collected 
with purse seines in marine waters of 
southeastern Alaska in 1983 and 1984 
and northern British Columbia in 1984. 
Associated prey assemblages were 
sampled with neuston and plankton 
nets in 1984. Salmon diets included at 
least 30 taxa of prey. Crustaceans (prin- 
cipally hyperiid amphipods), fish, and 
tunicates were the most important prey 
of pink ( O . gorbuscha ), chum ( O . keta), 
and sockeye (O. nerka) salmon. Fish 
were the most important prey of coho ( O. 
kisutch ) and chinook (O. tshawytscha ) 
salmon and made up the highest per- 
centage of stomach content weight for 
all salmon species. Diet shifted from 
crustaceans in 1983 to fish in 1984 for 
juvenile pink, sockeye, and chum 
salmon. Diet overlapped significantly 
(Cy>0.60) between pink and sockeye 
salmon, pink and chum salmon, and 
chum and sockeye salmon. Coho salmon 
diet overlap was <0.60 in all paired 
comparisons. Nearly all (98.6%) of the 
2,210 stomachs examined were at least 
half full. Although, in general, prey con- 
sumed were not very similar to prey 
observed in the environment, the com- 
position of salmon diets was more simi- 
lar to neuston collections than to zoo- 
plankton collections. 
Manuscript accepted 11 August 1997. 
Fishery Bulletin 96:285-302 (1998). 
Feeding habits of juvenile 
Pacific salmon in marine waters 
of southeastern Alaska and 
northern British Columbia 
Joyce H. Landingham 
Molly V. Sturdevant 
Auke Bay Laboratory, Alaska Fisheries Science Center 
National Marine Fisheries Service, NOAA 
I 1305 Glacier Highway, Juneau, Alaska 99801-8626 
E-mail address (for Molly Sturdevant, contact author): molly.sturdevant@noaa.gov 
Richard D. Brodeur 
Alaska Fisheries Science Center 
National Marine Fisheries Service, NOAA 
7600 Sand Point Way NE, Seattle, Washington 981 1 5-0070 
All Pacific salmon ( Oncorhynchus 
spp.) migrate as juveniles from shal- 
low waters near shore to coastal and 
oceanic feeding areas of the North 
Pacific Ocean, where species, stocks, 
and age classes mix (Hartt and Dell, 
1986; Ware and McFarlane, 1989; 
Pearcy, 1992). Substantial evidence 
suggests that salmon production 
around the Gulf of Alaska increased 
dramatically in the late 1970’s, pos- 
sibly owing to enhanced early ocean 
survival (Pearcy, 1992; Beamish and 
Bouillon, 1993; Brodeur and Ware, 
1995). Increased densities are evi- 
dent in the commercial harvest of 
salmon in Alaska; for example, 
salmon catch reached record num- 
bers in 1993, nearly doubling over 
25 years to approach 200 million 
fish (Wertheimer, 1997). This in- 
crease is attributed to several fac- 
tors, including growing enhance- 
ment efforts and environmental 
conditions that favor survival of both 
wild and hatchery salmon stocks. 
The increase in numbers of sub- 
adult and adult salmon feeding in 
marine waters has prompted inter- 
est in possible density-dependent 
effects on survival, growth, and pro- 
duction of salmon stocks around the 
Pacific rim (e.g. Helle, 1989; Kaeri- 
yama, 1989; Ishida et al., 1993; 
Helle and Hoffman, 1995). Fishery 
managers are concerned about the 
effects of increasing interactions 
between salmon populations — both 
wild and enhanced — in the various 
marine habitats where they mature 
(McNeil and Himsworth, 1980; 
Peterson et al., 1982; Brodeur, 1989; 
Brodeur and Pearcy, 1990; Pearcy, 
1992). The feeding ecology of juve- 
nile salmon is a pertinent, but not 
well known, topic. 
The objective of this study was to 
describe the feeding habits of juve- 
nile salmon during their first sum- 
mer in coastal waters of the east- 
ern Gulf of Alaska. Although Hartt 
and Dell (1986) summarized the dis- 
tribution, migration, and growth of 
juvenile salmon in the North Pacific 
Ocean and the Bering Sea, diet and 
feeding were addressed superfi- 
cially. Other references concerning 
juvenile salmon feeding habits dur- 
ing early marine residence, espe- 
cially along the open coast, are lim- 
ited (Pearcy, 1992; Brodeur 1 ), and 
juvenile salmon diets are often 
1 See next page for footnote. 
