Figure 4. High counts of total harbor seals and pups at Gertrude Island 
in southern Puget Sound. 
Killer whales, gray whales . The size of the pods of killer whales (Orca ) 
that visit the Sound most frequently has been increasing over the past 
10-15 years, while the membership in the transient pods that visit the 
region more infrequently has decreased. The size of the gray whale 
population that passes by the state on its way between Mexico and Alaska 
has steadily increased since federal protection was implemented. Some 
dead juvenile whales have been found in the Sound each year for at least 
the past four years. These deaths are to be expected with an estimated 
annual rate of calf mortality of 25% among a total population of roughly 
17,000 individuals. 
Community changes. 
Most community-level ecological research in the Sound has been directed to 
the benthos, those organisms that live in or on the bottom. Three major 
topical areas have been studied (Table 6). 
Soft-bottom benthos. The structure of soft-bottom benthic communities 
has been assessed in many studies involving several thousand samples. No 
thorough (statistical) synthesis of all these data has been performed and 
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