49 



trends in benthic stress and recolonization 

 patterns. 



REMOTS® data were not incorporated 

 into the DAMOS Program until 

 approximately three years after the 

 completion of STNH-S disposal 

 operations. The 1983 REMOTS® survey 

 at that station indicated that most of the 

 surface area was dominated by Stage I 

 species, with Stage III species appearing 

 only occasionally. Associated habitat 

 indices generally showed conditions 

 favoring continuing colonization (Figure 3- 

 7). By 1986, the area dominated by Stage 

 I organisms had been reduced slightly, and 

 the abundance of Stage III species had 

 increased. The OSI distribution showed a 

 similar increase (Figure 3-7). This trend 

 continued into 1987, with surveys showing 

 an increased dominance of Stage III 

 organisms and increasing organism- 

 sediment indices. 



This progressive recolonization 

 response appears to indicate long-term 

 environmental stability without any 

 indication of substantial sediment- 

 associated toxicity and morbidity. In light 

 of the bioassay results indicating that 

 exposure to the Stamford material would 

 result in finite mortality in the benthic 

 community (Moore 1978), the observed 

 trend suggests that the cap of New Haven 

 silts was effective in isolating local biota 

 from the sediment contaminants associated 

 with the Stamford material. 



3.2.3 A Case Study: MQR and the FVP 



Monitoring results from MQR have 

 indicated slower biological recolonization 

 rates after disposal relative to other CLIS 

 capped mounds, the uncapped FVP 

 mound, and the CLIS reference area. 

 These monitoring data have included 

 REMOTS® photographs (most recently, 

 summer surveys in 1991 and 1992), 

 sediment sampling and chemical analyses, 

 and bioassay studies. The complicated 

 disposal history at MQR, in tandem with 

 the unusual monitoring results gathered 

 since disposal completion, prompted more 

 intensive investigation of MQR following 

 the tiered monitoring protocols initiated by 

 NED to manage dredged material disposal 

 mounds (Germano et al. 1994). 



A survey of this area in 1983 following 

 deposition of both Mill and Quinnipiac 

 River sediments showed benthic conditions 

 to be essentially identical to those existing 

 at STNH-S, as discussed above (Figure 3- 

 8). Stage I organisms dominated the 

 surface, and OSI values ranged between 4 

 and 11. Following this survey, Black 

 Rock sediment was placed at MQR and 

 then capped with a large volume 

 (400,000 m 3 ) of New Haven Harbor silts 

 (Table 2-4). However, as mentioned 

 above, the depositional history of Black 

 Rock and New Haven material was 

 complicated by the approximately 

 3,000 m 3 of Black Rock Harbor material 

 deposited after the cap material was in 

 place (Figure 2-8). 



REMOTS® surveys as late as 1986 

 continued to show a dominance of Stage I 



Sediment Capping of Subaqueous Dredged Material Disposal Mounds 



