and S-percent glycerin, and identified to the lowest possible taxon; the 

 number of individuals per taxon was recorded for each core. 



One sediment sample per sampling period was taken at each station. 

 Median diameter, sorting (Folk and Ward, 1957), and percent sand and silt 

 were computed using Emery's (1938) tube analysis. Total carbon was meas- 

 ured by a Leco Carbon Analyzer (Table 7) . 



Table 7. Average sedimentological parameters at 

 the three control stations. 





rr 





Stations 





Paramet« 



6 m 



10 m 



20 m 



Pet carbon 





0.08 



0.08 



0.12 



Pet sand 





97.3 



90.4 



92.2 



Pet silt 





2.7 



9.6 



7.8 



Sorting 





0.41 



0.44 



0.40 



Median grain 



size 



0.11 



0.99 



0.95 



Biomass was estimated because of the shallow penetration (15 centi- 

 meters) and the small area sampled (0.018 square meter) by the corers. 

 Large animals have the most effect on biomass; they are more widely dis- 

 tributed and live deeper in the sediment (Holm, 1964; Masse, 1972; Smith 

 and Howard, 1972; Oliver, 1973). At the 10-meter control station, 54 

 percent of the biomass was above 10 centimeters in the sediment; 95 per- 

 cent was above 20 centimeters (from the top 50 centimeters) of the sedi- 

 ment (Oliver, 1973) . At the 20-meter control station, 39 percent was 

 above 10 centimeters and 61 percent above 20 centimeters. 



For brevity and clearness, a number of groups were classed under 

 "worms"; over 80 percent of the species and individuals of the worm fauna 

 were polychaetes. The taxa were grouped because of their obvious morpho- 

 logical and ecological similarities (App. B) . 



The number of species (lowest taxon) was presented in two ways: (a) 

 The total number of species per sample (usually in eight replicates) , and 

 (b) the mean number of species per core (0.018 square meter) with 95- 

 percent confidence intervals. These are two distinct parameters, but 

 they generally follow the same trend. The number per core gives a meas- 

 ure of variation. 



Species diversity was measured by Shannon and Weaver's (1963) equation; 

 evenness by J (Pielou, 1966). Both were computed for the total sample 

 (Peterson, 1972) : 



32 



