1.0 INTRODUCTION 



The Central Long Island Sound Disposal Site (CLIS) is located approximately 6 ran 

 south of New Haven Harbor, Connecticut (Figure 1-1). Environmental monitoring by the 

 U.S. Army Corps of Engineers, New England Division (NED) has occurred at the site since 

 1972. A primary objective of past investigations has been to assess the environmental impact 

 of dredged material disposal, particularly the postdisposal recovery of benthic ecosystems. A 

 secondary historical objective has been to monitor the location of dredged material, the 

 height, areal extent, and stability of the dredged material mounds, and postdepositional 

 dispersion of material. 



Several active and inactive disposal mounds currently exist at CLIS (Figure 1-2). The 

 previous monitoring survey at CLIS, conducted in July 1990 (Germano et al. 1993), 

 monitored the disposal activity occurring at CLIS between 1988 and 1990. Results from the 

 July 1990 survey included the detection of the CLIS-88 and CLIS-89 disposal mounds, as 

 well as the small capped mound, CS-90-1. 



During the 1990/91 disposal season, 67,730 m 3 of dredged material was disposed in 

 the northwest quadrant of CLIS. Barges released most of this material (59,000 m 3 ) at the 

 CLIS-90 buoy. Approximately 8,730 m 3 was additional cap material placed on the CS-90-1 

 mound. The CLIS-90 buoy and CS-90-1 were the only two disposal locations to receive 

 dredged material between the July 1990 and the June 1991 surveys. 



SAIC conducted the field operations at CLIS from 16 to 23 June 1991. The field 

 work consisted of a precision bathymetric survey, Remote Ecological Monitoring of the 

 Seafloor (REMOTS®) sediment-profile surveys, dissolved oxygen (DO) and 

 conductivity /temperature/depth (CTD) profiles, and sediment sampling for poly nuclear 

 aromatic hydrocarbons (PAHs), grain size, and total organic carbon. The objectives of this 

 study were 



1) to delineate the footprint and topographic elevation of dredged sediment 

 deposited at the CLIS-90 buoy location since the July 1990 Disposal Area 

 Monitoring System (DAMOS) survey by means of a precision bathymetric 

 survey and sediment-profile photography; 



2) to determine the successional status of mounds that have received dredged 

 material since September 1990 (CLIS-90 buoy location and CS-90-1 mound 

 capping) and to monitor conditions at the inactive mounds CS-1, CLIS-88, 

 CLIS-89, NHAV-74, FVP, and MQR. The results were to be used to test 

 hypotheses and predictions that form part of the DAMOS tiered monitoring 

 and management protocol; 



Monitoring Cruise at the Central Long Island Sound Disposal Site, June 1991 



