FISHERY BULLETIN: VOL. 71, NO. 3 



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EATER BEACH 



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Figure 2. — Cumulative frequency curves for sediment 

 samples taken in 2-cm intervals of depth at the three 

 study areas in Galena Bay. 



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the growth of these clams. In this paper length 

 data is included for comparative purposes. 



Age was estimated for all clams less than 

 20 mm in length utilizing the annular method 

 (Weymouth, 1923). All the larger clams from 

 Shell Beach, one station on Eater Beach, and 

 one station on Indian Creek Flat were also 

 aged. In the aging procedure the distance 

 between annuli^ was measured along the radial 

 sculpture line that originated at the approxi- 



mate center of the umbonal region and roughly 

 bisected the ventral margin of the shell (Fig- 

 ure 3). 



BIOMED programs BMDOID, BMD05D, 

 and BMDOIV were adapted for this investiga- 

 tion (Dixon, 1965), and data were processed 



3 Annulus-A series of closely spaced concentric growth 

 rings; the result of slow growth at low winter temperatures. 



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