Laake et al : Pinniped diet composition 



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Figure 1 



Average biomass proportion (/r^) of each prey group in the diet of harbor seals on the Columbia River between 1995 and 1997 

 for spring (A), summer (B), and fall (C). 



anchovy (Engraulis mordax) were consumed in greater 

 quantity but they were not always a large proportion of 

 the reconstructed biomass. 



Using spHt-sample frequency of occurrence (SSFO) to 

 estimate diet composition, the results were dramatically 

 different for larger and smaller prey items (Fig. 3). For 



