FISHERY BULLETIN: VOL. 81, NO. 1 



some factors not specifically measured. How- 

 ever, reliance upon these effects should be avoid- 

 ed when possible and caution should be exercised 

 when interpreting the results. 



The a> parameter proved useful, both for its de- 

 scription of growth rate and ease of manipula- 

 tion in further analyses. Incorporating both the 

 sample size and variance of the age-length deter- 

 minations into the nonlinear regression protected 

 oj against random errors in the location of the 

 age-length modes. In addition, since w is more 

 robust than either Kor L x , it is further protected 

 against inaccuracies in their estimation — an 

 advantage over using K during the subsequent 

 growth analyses. The trends resulting from the 

 subsequent regressions were also protected from 

 random inaccuracies in the estimation of to by 

 virtue of the large number of sample sites used. 

 However, it is important to recognize that such 

 random errors do exist and not to continue the 

 analysis past its potential limits. 



ACKNOWLEDGMENTS 



The author wishes to express his gratitude to 

 those people who assisted in the clam collection, 

 particularly R. L. Dow, M. Richards, J. M. Hick- 

 ey, M. L. H. Thomas, and M. Worobec; and to 

 those people who were involved in the sample 

 processing, notably R. S. Brown, J. Keller, A. 

 Miller, S. Polofsky, C. Brown, and E. Franklin. 

 S. B. Saila, A. N. Sastry, R. C. Bullock, and two 

 journal reviewers gave helpful criticism. Finan- 

 cial support for sample collection was provided 

 by the American Petroleum Institute. 



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