REPORT DOCUMENTATION PAGE 



form approved 



0MB No. 0704-0188 



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1. AGENCY USE ONLY (LEAVE BLANK) 



2. REPORT DATE 



APRIL, 1999 



3. REPORT TYPE AND DATES COVERED 



FINAL REPORT 



4. TITLE AND SUBTITLE 



MONITORING CRUISES AT THE WESTERN LONG ISLAND SOUND DISPOSAL SITE 

 SEPTEMBER 1997 AND MARCH 1998 



5. FUNDING NUMBERS 



6. AUTHOR(S) 



PEGGY MYRE MURRAY and HEATHER L. SAFFERT 



7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 



Science Applications International Corporation 

 221 Third Street 

 New^jort, RI 02840 



8. PERFORMIGORGANIZATION 

 REPORT NUMBER 



SAIC-441 



9. SPONSORING/MONirORING AGENCY NAME(S) AND ADDRESS(ES) 



US Army Corps of Engineers-New England Branch 

 696Virginia Rd 

 Concord, MA 01742-2751 



10. SPONSORING/MONrrORING 

 AGENCY REPORT NUMBER 



DAMOS Contribution No. 125 



11. SUPPLEMENTARY NOTES 



Available from DAMOS Program Manager, Regulatory Branch 

 USACE-NAE , 696 Virginia Rd, Concord, MA 01742-2751 



12a. DISTRIBUTION/AVAILABILnY STATEMENT 



Approved for public release; distribution unlimited 



12b. DISTRIBUTION CODE 



13. ABSTRACT 



A monitoring survey was conducted at the Western Long Island Sound Disposal Site (WLIS) from 16 to 18 September 1997 and from 5 to 6 

 March 1998 aboard the MA' Beavertail as part of the Disposal Area Monitoring System (DAMOS) Program. Field efforts in September focused on the 

 active southwestern quadrant of WLIS and consisted of precision bathymetry and Remote Ecological Monitoring of the Seafloor (REMOTS®) to monitor 

 the development, stability, and benthic conditions of the disposal mounds. The September 1997 survey documented changes in bottom topography at the 

 disposal area relative to July 1996. Approximately 35,000 m' of dredged material was disposed on the WLIS seafloor during the 1996-1997 disposal 

 season to form the I mound. Using REMOTS® sediment-profile photography, we evaluated the benthic recolonization status and sediment conditions of 

 the new I mound and the 1996 H mound, relative to reference areas, SOUTH and SW-REF. 



Additional field work was conducted from 5 to 6 March 1998 to investigate potential sites for a new reference area and compare seasonal effects 

 on benthic conditions in REMOTS® photographs. At the present time, only two reference areas near WLIS have been accepted to represent ambient 

 conditions for the region. The DAMOS protocol requires that three reference areas be used both for comparing the conditions between ambient 

 environments and dredged material disposal mounds, and for evaluation of dredged sediments for disposal permits at WLIS. 



Depth difference calculations and mapping of bathymetric data depicted the I mound below the buoy location, 40"59.203' N, 73"29.072' W 

 (NAD 27), between the D and G mounds. The mound was 3.7 m high with a diameter of about 150 m. REMOTS® sediment-profile photography 

 indicated benthic recolonization of Stage I organisms in September and more advanced Stage III indicators in March. The redox potential discontinuity 

 (RPD) depths, which indicate depth of sediment oxidation, also increased from September to March. 



The H mound was developed in the spring of 1996, when the WDA buoy, deployed at 40°59.228' N, 73°28.732' W, received approximately 

 15,300 m^ of sand, silt, and clay. The deposition of this material formed a 1.5 m high mound, approximately 230 m in width. REMOTS® photography 

 detected a solid Stage 1 pioneering polychaete conununity with increased evidence of Stage III activity in September relative to the July 1996 survey. RPD 

 depths were shallower in September than July, but did increase again in March. The number of advanced successional status indicators in the photographs 

 increased in the March surveys. 



The widespread presence of historic dredged material in the region surrounding WLIS has complicated our ongoing search for a suitable third 

 reference area for this disposal site. Sediments from shipping port along the Connecticut and New York coasts have been dredged and disposed in Long 

 Island Sound since the late 1800s, long before a developed management plan was in operation. In 1954, eight disposal sites were in existence for the 

 western Long Island Sound region. WLIS is located between three of these historic sites which received large volumes of dredged materials until the 

 1980s. Using side-scan sonar survey real-time data as a guide, we identified a new potential reference area (SE-REF) for WLIS (40"59.203' N, 

 73"29.072' W). Further investigation showed that SE-REF met many of the specified requirements for selection of a reference area. While we 

 recommend SE-REF as a third reference area, we recognize that survey data could not conclusively rule out the presence of historic dredged material. 

 Future monitoring surveys should continue to investigate and confirm the absence of historic dredged material at SE-REF. 



14. SUBJECT TERMS 



Western Long Island Sound (WLIS), Remote Ecological Monitoring of the Seafloor 

 (REMOTS), bathymetry, sediment oxidation , dredged material 



15. NUMBER OF TEXT PAGE S: 80 



16. PRICE CODE 



17. SECURITY CLASSIFICATION OF 

 REPORT Unclassified 



18. SECURITY CLASSIFICATION 

 OF THIS PAGE 



19. SECURITY CLASSIFICATION 

 OF ABSTRACT 



20. LIMITATION OF 

 ABSTRACT 



