REPORT DOCUMENTATION PAGE 



OM» NO. 704-0 tU 



1. AGENCY USE 0NLT (<.•«»» ot+n*.) 



1. »EPORT GATE 

 December 1990 



J. REPORT TYPE AMD DATES COVERED 

 Final Report 



A. TTTU ANO SUBTTTU 



Preliminary Field Operations in Support of Disposal Site 

 Designation in the Rhode Island Sound Region 



fc. AUTHOWS) 



S. FUNDING NUMBERS 



7. PERFORMING ORGANIZATION NAME(S) AND AOORESSUS) 



Science Applications International Corporation 

 221 Third Street 

 Newport, RI 02840 



8. PERFORMING ORGANIZATION 

 REPORT NUMBER 



SAIC-88/7525 & C69 



9. SPONSORING' MONITORING AGENCY NAMEISI ANO ADORESSUS) 



U.S. Army Corps of Engineers - New England Division 

 424 Trapelo Road 

 Waltham, MA 02254-9149 



10. SPONSORING/ MONITORING 

 AGENCY REPORT NUUUI 



DAMOS Contribution No. 79 



11. SUPPLEMENTARY NOTES 



Available from DAMOS Program Manager, Regulatory Division 

 USACOE-NED, 424 Trapelo Road, Waltham, MA 02254-9149 



Ui. DISTRIBUTION / AVAILABILITY STATEMENT 



Approved for public release; distribution unlimited. 



U& DISTRIBUTION CODE 



ABSTRACT IftHMimvm <0O wofmi 



During the period 4 September to 14 October 1987, field operations were conducted in selected areas of Rhode Island 

 Sound (RIS) and Narragansett Bay to gather information for a feasibility assessment of offshore dredged material disposal sites. 

 A total of four discrete areas were studied; three in RIS (Brenton Reef, Brenton-A, and Brenton-B) and one in Narragansett Bay 

 (Prudence). Field operations included bathymetric, side scan and sub-bottom surveys, sediment-profile photography 

 (REMOTS*), and sediment sampling for physical and benthic community analyses. 



The physical boundaries of the historic disposal mound at the Brenton Reef disposal site had not changed since the last 

 (1981) survey of the area; the mound was a well-defined feature centered just inside the western boundary of the disposal site with 

 a diameter of roughly 1600 meters and a minimum depth at the apex of 25 J meters. The areas of Brenton-A and Brenton-B were 

 characterized by extensive glacial drift deposits. A relict channel system that drained the landward side of the recessional moraine 

 was observed in sub-bottom profiles trending northeast-southwest through these two areas. The Prudence Island site side-scan data 

 revealed mound-like features ( < 2 m in height; 10 -20 m in diameter) on an otherwise uniform surface. 



The benthic communities around the Brenton Reef disposal mound showed a full recovery in population density since the 

 cessation of disposal operations. Dense ampeliscid beds were observed on the ambient seafloor within and outside the site as well 

 as on the edge of the mound; a mobile sand community dominated the mound central area where a distinct transition in sediment 

 grain size occurred. The density of lobster traps on and around the disposal mound attested not only to the benthic community 

 recovery but to the enhanced fishery resource which exists at the site. 



14. SUBJECT TERMS 



Rhode Island Sound 

 dredged material 

 sediments 



REMOTS 



sediment profile photography 



bathymetry 



IS. NUMBER OF PAGES 



92 



lb. PRICE COOt 



17. SECURITY CLASSiFtCATlOK 

 OF REPORT 



Unclassified 



IB. SECURITY CLASSIFICATION 

 OF THIS PAGE 



i9. security classification 

 of abstract 



io. limitation of abstract 



H%H /SAO-OWaO-iiGCi 



itinoiro -orm i}8 Iftvv <-49l 

 * ■ ■ ■ wi m mm va. uvu 



