Shoals or Brenton Reef, Rhode Island. The Rockland dump site has been 

 inactive for several years, yet surface sediments are not greatly different 

 from the two reference samples. The single harbor sample shows very low 

 iron content and about the same metal composition as the dump and reference 

 samples. A third reference sample taken near the dump site in Penobscot 

 Bay resembles the harbor sample's composition. 



Biochemical Studies 



Table A-2 summarizes the heavy metal concentration of M. modiolus samples 

 placed on the Rockland disposal site at 44° 07' 18.2" N, 690 00' 05.1" W 

 and from reference samples taken at Drunkards Ledge approximately 3 NM south- 

 east of the disposal site. These data are presented for analysis in Fig- 

 ure A-4. The data indicate there are no significant differences between 

 the concentrations of Cd, Cr, Cu or Hg either between the reference and 

 disposal site stations or with time. However, the concentration of Pb in 

 M. modiolus samples from Drunkards Ledge on May 12 and August 7, 1978 is 

 significantly less than that of the baseline data. A similar significant 

 reduction in the concentration of Fe is observed in the mussels sampled on 

 August 7 from the reference site. 



Benthic Macrofauna 



As indicated by Table A-3 only two species comprise 95% of the species 

 present at the Rock! and site. Obviously more data are required before 

 more extensive interpretations of the benthic population dynamics can be 

 accomplished. 



