Figure 1. — Locations sampled for hard clams, Mcrcenaria mercenana . in Raritan Bay during 1974 to 



early 1975 and 1978. 



ical tests of some metals, using the same dredge 

 operated from the NMFS RV Kyma. 



Following sampling operations at each site, the 

 length (longest anterio-posterior dimension), 

 height (deepest dorso ventral dimension from the 

 umbo to ventral shell margin) and width (thickest 

 lateral dimension) of each clam shell was meas- 

 ured to the nearest millimeter with vernier 

 calipers. About 20 clams were then opened and 

 the meat and shell liquor packaged for immediate 

 freezing. Later measurements were made of the 

 drained meat weight, dry meat weight, and per- 

 cent solids by methods outlined by Ropes (1971a) 

 for other bivalves. 



Specimen shells for age and growth observa- 

 tions of hard clams were chosen from Ward Point 

 and New Dorp Beach samples, since clams from 

 these sites exhibited extremes in shell and weight 

 measurements. The selection included five clams 

 in a sample having the smallest mean size, five in 

 a sample having the largest mean size, and those 

 in a sample having a mean size nearly equal to 

 the grand mean for all samples taken at the par- 



ticular site. The shells were radially sectioned 

 and the cut edge polished to a high luster, as 

 described by Peterson et al. (1983) to facilitate 

 detection of annual growth lines. 



Ten additional clams were opened and the soft 

 body tissues were removed for preservation in 

 Bouin's fixative. Methods used for dehydrating, 

 embedding, sectioning, and staining gonadal tis- 

 sues to prepare slides for microscopic examina- 

 tion of the reproductive cycle were as outlined by 

 Ropes and Stickney (1965) and Ropes (1968). 

 Stages in the development of gonadal tissues 

 were established. The progressive development of 

 sex cells through early to ripe condition and even- 

 tual expulsion by spawning activity was a basis 

 for evaluating reproductive viability. Failure to 

 complete all stages of a cycle was considered an 

 indication that the clams were being impacted by 

 environmental conditions. 



Specimens were collected for histochemical 

 tests on 1 November 1978 (10 hard clams and 2 

 oysters from Ward Point and 10 hard clams from 

 New Dorp Beach). The soft body mass of each 



654 



