4.2 REMOTS Sediment Profile Photography 



The present REMOTS survey indicates that the areal 

 extent of dredged material was well within the disposal site 

 boundaries and, in large part, the material occurred within 400 

 meters of the disposal buoy. In many of the REMOTS images, it was 

 difficult to determine precisely how much of this dredged material 

 was deposited during the past year versus previous years. 

 Comparing the bathymetric contours from 1986 and 1987 (Figures 3-1 

 and 3-2) shows the disposal mound formed in the past year was 

 approximately 300 m in diameter and centered southeast of the 

 disposal buoy. The REMOTS data (Figure 3-3) indicates that 

 dredged material layers in excess of the prism penetration (i.e., 

 greater than about 15 cm in thickness) extended approximately 200 

 m farther west, south, and southeast than indicated by the 

 bathymetric data. If these layers had actually been deposited 

 since the 1986 survey, then they should have been detected 

 acoustically. The fact that no changes in bathymetry correspond 

 with these dredged material layers suggests that much of this 

 material was probably not deposited in the past year but rather 

 represents material which was seen in these locations (with both 

 REMOTS and bathymetry) at the time of the July 1986 survey. 



Some clayey and sandy sediments, probably allocthonous, 

 were present approximately 400 meters northwest of the disposal 

 point. This may represent the dredged material which was 

 mistakenly disposed in this area. However, due to the sediment 

 heterogeneity present at this site, definitive identification of 

 these materials as new dredged material was not possible. 



Infaunal recplonization at the site is proceeding well 

 within expected rates based on previous DAMOS surveys; head-down 

 deposit-feeding assemblages (Stage III) were found across the 

 survey area. This indicates that significant infaunal 

 recolonization has occurred since the 1986 survey. Also, 

 tubicolous amphipods (Stage II taxa) continue to be a major faunal 

 component of the region. At the three reference stations located 

 west, northeast, and east of the disposal site, Stage III taxa 

 were also abundant, while Stage II forms were observed only at the 

 eastern reference station (NLON-Ref ) . 



4.3 Dissolved Oxygen Regime 



In view of the objectives of the CTD/DO sampling at New 

 London, the results illustrate the difficulties in characterizing 

 oceanographic dissolved oxygen regimes based on instantaneous 

 measurements at this site. A major confounding factor stems from 

 the fact that the New London site is located within an estuary, 

 very close to the opening to the Atlantic Ocean (The Race) , where 

 dissolved oxygen concentrations typically vary diurnally, tidally, 



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