Table 8. Average number of species (S) per sampling 

 period and individuals (N) per core at the 

 6-, 10-, and 20-meter control stations. 



Fauna 



Depth 



6 m 



Pet 



10 m 



Pet 



20 m 



Pet 



Crustaceans N 

 S 



34 

 10 



72 

 37 



91 

 11 



56 



22 



22 

 14 



17 

 21 



Mollusks N 

 S 



3 

 5 



6 

 19 



35 

 11 



21 



22 



30 

 13 



24 

 19 



Worms N 

 S 



10 

 12 



21 

 44 



37 

 28 



23 

 56 



75 

 41 



59 

 60 



Total N 

 S 



47 

 27 



-- 



163 

 50 



__ 



127 

 68 



_- 



after settlement, 

 meter station. 



The rare adult bivalves were usually found at the 20- 



The 10- and 20-meter control stations were characterized by N. elegans. 

 Euphilomedes spp. and Paraphozus spp. were codominants with N. elegans at 

 the 10-meter station; Magelona spp. was codominant with N. elegans at 20 

 meters. Adult Tellina were rare; they were common in a shallow (16 meters) 

 area studied in the north Monterey Bay (Watson and Stephenson, 1972). The 

 6-meter station was characterized by small crustaceans and B. eceentvicus. 



Barnard (1963) found that crustacean abundance increased to a depth 

 of 60 meters and was more abundant in deeper water; however, a benthic 

 survey of the north Monterey Bay (16- to 60-meter depths) indicated that 

 crustacean density was highest at the shallowest station sampled (Hodgson 

 and Nybakken, 1973). At the control area, crustaceans were more abundant 

 at the 10-meter station. Lie and Kisher (1970) and Masse (1972) also 

 found a greater number of crustaceans in considerably shallower water 

 than Barnard (1963) did. In addition, the number of crustaceans per meter 

 square at the control area was an order of magnitude greater than that 

 reported by Barnard. 



Lie and Kisher (1970) and Masse (1972) noted the same general increase 

 in crustaceans and decrease in worm fauna in shallow water that was ob- 

 served along the control transect. The primary reason for this separation 

 is the physical stress created by wave-induced sediment movement. Tubes, 

 burrows, and other structures are difficult to maintain in shallow water. 

 Sediment stability allows an increase in habitat diversity, which probably 

 accounts for much of the increase in species from the shallow to deeper 

 stations. 



The dominant crustacean at the 20-meter control station was P. daboius. 

 There was a highly significant correlation (r = 0.89, p 0.001) between the 

 number of P. daboius and the total number of individuals. The correlation 



34 



