The findings and concerns generated by the 1991 survey data dictated some of the 

 objectives of the 1992 monitoring operations. The specific objectives of the 1992 survey 

 were 



• to delineate the areal distribution and topography of dredged material deposited since 

 the July 1991 survey; 



• to assess the extent of infaunal recolonization on the active WLIS "F" mound; 



• to investigate locations for two new reference areas to replace existing reference areas 

 2000S and WLIS-REF; and 



• to further assess habitat conditions and sediment toxicity at those stations near the 

 WLIS "D" mound which exhibited poor habitat conditions during the 1991 survey. 



Science Applications International Corporation (SAIC) conducted field operations at 

 WLIS from 28 July to 30 July 1992. Field operations included bathymetric surveying, 

 REMOTS® sediment-profile photography, near-bottom and near-surface dissolved oxygen 

 (DO) measurements, and sediment sampling for metal and polycyclic aromatic hydrocarbon 

 (PAH) chemistry analysis, total organic carbon (TOC), and grain size determination. 



The 1992 monitoring plan was designed to test the following predictions that are part 

 of the DAMOS tiered monitoring protocol: 



• Based on a disposal simulation model, the volume of sediments disposed at WLIS 

 from November 1991 to May 1992 (39,700 m 3 ) should have resulted in the formation 

 of a distinct mound at the disposal buoy location. 



• At the disposal point, benthic recolonization should be predominantly in Stage I, 

 while recolonization on the flanks of the mound should be primarily Stage II and/or 

 Stage III. Stage I consists of small pioneering polychaetes while Stage II is 

 characterized by tubicolous amphipods and Stage III by larger burrowing (head-down) 

 deposit feeders. Stage III taxa represent high-order successional stages typically 

 found in low disturbance habitats. 



• Near-bottom dissolved oxygen concentrations should be similar at stations within the 

 disposal site and at the reference areas. 



• Stage III infaunal activity and recolonization should have developed and deepened the 

 apparent redox potential discontinuity (RPD) boundary layer at suspect stations near 

 the WLIS "D" mound. 



Monitoring Cruise at the Western Long Island Sound Disposal Site, July 1992 



