KAPLAN, WELKER, and KRAUS: EFFECTS OF DREDGING 



Table 10 summarizes an analysis of variance of 

 the biomass at the Goose Creek stations according 

 to sediment type. Separate analyses were per- 

 formed on the data for stations 2-25; 2-25 plus 

 channel stations A-J, M; and channel stations 

 A-J, M alone. 



Significance was found in all three analyses 

 only among dry weights before and after dredging. 

 There was no significance in the variances among 

 substratum types, nor among the interactions 

 of substrata and pre- and post-dredging bio- 

 mass. There was, then, no systematic effect of 

 particular sediment types alone on the rate of 

 recovery of the in- and epifauna, even in the 

 channel. 



A four- way analysis of variance was performed 

 to examine the relationship between seasons and 

 variances in biomass at each station, without 

 considering pre- and post-dredging effects. Sta- 

 tions 2-18 were studied. The unrepresented 

 stations are in the less saline western half of 

 Goose Creek which was frozen over during Jan- 



uary and February of both years. There were no 

 significant differences in the seasonal variances 

 among stations, indicating that seasonal fluctua- 

 tions in biomass were not factors which accounted 

 for the differences in biomass, heretofore attrib- 

 uted to the dredging operation. Table 11 sum- 

 marizes the statistics for the analysis of variance 

 according to seasons. 



Another four- way analysis of variance was per- 

 formed to examine the relationship between 

 seasonal variances and substratum type for 

 stations 2-25. Again, there was no significance in 

 any of the interactions, indicating that variances 

 in biomass are not a function of season, sediment 

 type, or of an interaction between these factors. 

 This analysis is summarized in Table 12. 



It was expected that the channel would show 

 substantial effects of the dredging process, since it 

 was from the channel that massive quantities of 

 substratum were removed. The sediment and its 

 inhabitants were physically removed to a depth of 

 2 m. What is of greater importance is the evidence 



Table 10. — Analyses of variance of pre- and post-dredging dry weights according to sediment type in the bay 



and channel. 



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