22_ 



The successional status was primarily characterized by Stage I pioneering 

 assemblages of polychaetes in September as predicted by DAMOS protocol. Several 

 replicates indicated the presence of a higher successional stams containing Stage III taxa or 

 feeding voids due to the deposit feeder's biological activity (Figure 3-3). The average 

 mean RPD for the I mound was moderate to shallow with a depth of 1.93 cm, varying 

 from 0.92 cm to 6.81 cm. The overall median OSI value was 4 (Figure 3-4, Table 3-1). 

 The central 5-station grid stations, resurveyed in March, had an average RPD of 2.25 cm 

 and OSI of 7 in September. 



The successional status in March indicated a slightly greater presence of Stage III 

 organisms (Figure 3-3). The RPD depths were significantly deeper than observed in 

 September with an overall average depth of 2.56 cm (Figure 3-5); however, wiper smears 

 obstructed measurements in a number of replicates. In March, the 5-station grid OSI value 

 of 8 was slightly higher than in September and may be attributed to seasonal effects on 

 sediment oxygen contents and the progression in the successional stams (Figure 3-5). No 

 low dissolved oxygen conditions were observed in the replicates from either the September 

 or March survey. 



3.3 WLIS H Mound 



During the 1995-1996 disposal season, 15,300 m^ of sand, silt, and clay dredged 

 from the Cormecticut and New York waterways were disposed at WLIS and formed the H 

 mound. About two- thirds of the material, 10,060 m^ barge volume, was dredged from 

 Coimecticut's Wlison Cove, Norwalk and Stamford Harbors, and Pratt's Cove. The 

 remaining material, 5,240 m^ barge volume, derived from New York's Manhasset Bay 

 along the north shore of Long Island. REMOTS® data from the 1996 monitoring survey 

 indicated healthy condition relative to reference values, with a moderate-to-deep RPD and 

 evenly distributed benthic recolonization (Morris 1998). We revisited WLIS H in 

 accordance with DAMOS monitoring protocols to observe the benthic conditions and 

 examine evidence for the predicted advanced successional stams that occurs with a healthy 

 benthic recovery over the long-term. 



3.3.1 Bathymetry 



The September 1997 bathymetric survey area did not extend over the H mound. 

 The 1996 bathymetric survey chart of this smaller area was used as a basemap for the 

 REMOTS® data, showing a sediment mound with a minimum depth of 32.5 m (MLLW) 

 over the apex of the H mound (Figure 3-6). 



Monitoring Cruise at the WLIS Disposal Site, September 1997 and March 1998 



