46 Fishery Bulletin 120(1) 
Table 2 
Split-sample frequency of occurrence (SSFO) and estimated metric tons (t) of prey consumed by major prey group (family, order, 
or class) and by the lowest identifiable taxonomic group (indented) for prey consumed by Steller sea lions (HEumetopias jubatus), 
based on examination of scat samples collected from 2010 through 2013 in northwest Washington. Numbers of different types of 
scat samples by season are also provided. The SSFO calculations for major prey groups and for the lowest identifiable taxonomic 
groups were performed separately and, as a result, produced slightly different values. 
Total Spring Summer Fall Winter 
Sample type No. of samples 
Scat samples 
Samples containing identifiable prey 
Samples containing no identifiable prey 
Empty samples 
Prey consumption 11,327 t 2998 t 2039 t 3821 t 2469 t 
Prey group SSFO SSFO SSFO SSFO SSFO 
Herrings, shads, sardines: family Clupeidae 22.7% 13.8% 36.7% 6 21.0% 13.3% 
Clupeids, unidentified 11.3% 9.3% 15.2% A 10.7% 8.1% 
Pacific sardine (Sardinops sagax) 6.6% 0.0% 0 18.5% : 3.0% 0.1% 
Pacific herring (Clupea pallasii) 3.9% 2.6% 3.0% : 6.2% 4.0% 
American shad (Alosa sapidissima) 1.3% 1.9% d 0.1% : 1.9% : 1.5% 
Rockfishes: family Sebastidae 13.9% 17.9% 8.3% : 8.5% 25.8% 
Rockfishes (Sebastes spp.) 13.8% 17.7% 8.2% : 8.4% 25.7% 
Skates: family Rajidae 13.1% 15.8% 9.2% 6 10.7% 19.5% 
Skates, unidentified 12.7% 15.5% 8.8% : 10.2% 19.3% 
Salmon: family Salmonidae 11.7% 12.6% 5.8% 9 15.4% 15.8% 
Salmon or trout, unidentified 11.6% 12.6% 5.7% : 15.1% 15.7% 
Flatfishes: order Pleuronectiformes 9.7% 8.8% 15.0% 9 10.1% 1.3% 
Starry flounder (Platichthys stellatus) 4.4% 4.1% 6.9% : 4.4% 0.2% 
Righteye flounders, family Pleuronectidae 2.0% 1.8% ; 2.3% : 3.0% 0.4% 
Arrowtooth flounder (Atheresthes stomias) 1.3% 1.0% 3.2% : 0.4% : 0.0% 
Flatfishes, unidentified 0.9% 0.7% 1.2% : 0.9% . 0.4% 
Butter sole (sopsetta isolepis) 0.6% I 0.5% : 1.1% : 0.6% : 0.0% 
Rex sole (Glyptocephalus zachirus) 0.3% : 0.0% i 0.6% : 0.6% F 0.1% 
Sanddabs (Citharichthys spp.) 0.3% I 0.2% : 0.2% : 0.5% I 0.0% 
English sole (Parophrys vetulus) 0.2% : 0.6% : 0.0% ! 0.3% ; 0.1% 
Dover sole (Microstomus pacificus) 0.2% ; 0.4% : 0.2% ! 0.1% : 0.2% 
Sand sole (Psettichthys melanostictus) 0.1% : 0.3% : 0.0% i 0.0% I 0.0% 
Slender sole (Lyopsetta exilis) 0.1% ‘ 0.0% ! 0.2% : 0.0% i 0.0% 
Turbots (Pleuronichthys spp.) <0.1% : 0.0% i 0.0% ; 0.1% ; 0.0% 
Dogfish sharks: family Squalidae 8.3% A 10.4% : 5.6% : 9.3% : 9.0% 
Pacific spiny dogfish (Squalus suckleyi) 8.2% : 10.4% : 5.5% : 9.1% 
Hakes: family Merlucciidae 5.9% : 0.9% : : : 8.6% 
Pacific hake (Merluccius productus) 5.8% Y 0.9% : L i 8.5% 
Cods: family Gadidae 4.8% I 9.0% } ; : 3.6% 
Cods, unidentified 2.1% : 3.5% : i : 1.7% 
Walleye pollock (Gadus chalcogrammus) 1.4% : 5.1% H I i 0.3% 
Pacific cod (Gadus macrocephalus) 1.2% : 0.4% J i : 1.6% 
Pacific tomcod (Microgadus proximus) <0.1% : 0.0% I : é 0.0% 
Anchovies: family Engraulidae 2.1% : 2.1% i ; F 2.8% 
Northern anchovy (Engraulis mordax) 2.0% y 2.1% : ; : 2.8% 
Greenlings: family Hexagrammidae 1.7% : 2.2% : : : 2.6% 
Lingcod (Ophiodon elongatus) 1.1% : 2.1% ; ! d 1.3% 
Hexagrammids, unidentified 0.4% : 0.0% } I I 0.8% 
Atka mackerel (Pleurogrammus 0.1% 3 0.0% i I 1 0.5% 
monopterygius) 
Squids and octopuses: class Cephalopoda 1.1% } 0.8% : ! : 2.2% 
Squids and octopuses, unidentified 0.8% i 0.5% : : 3 1.5% 
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