3.0 RESULTS 



Three replicate photographs were successfully taken and developed at all 21 stations 

 (Appendix). Only one replicate photograph at 130NE was not analyzed; the obscured image 

 was attributed to either a collapsed burrow or an artifact of the camera (pullout). 



Results from this year's survey are discussed in terms of (1) the distribution of 

 quantified REMOTS® parameters over the mound, (2) the benthic habitat, as measured by 

 successional stages of organisms and the multiparameter Organism-Sediment Index (see 

 below), and (3) specialized observations which are important in describing the state of MQR. 

 Since none of the CLIS reference areas were sampled in 1992, MQR REMOTS® photographs 

 were compared to reference data from the 1991 survey. Results from the most recent survey 

 were also compared with results from the June 1991 survey for each category. The station 

 locations were not identical between the two surveys due to the increased station density of 

 the 1992 survey (Figure 2-1). Because of this discrepancy, only stations within 200 meters 

 of the center station were used for comparison purposes. 



Results of REMOTS® analyses indicated that benthic ecological factors have improved 

 over the 14-month period since the last REMOTS® survey in June of 1991. Although 

 benthic conditions have improved at MQR since 1991, they remain below reference levels. 

 These indications of recovery were not considered sufficient to alter plans of capping. For 

 this reason bioassay analyses were not conducted. 



3.1 Distribution and Ranges of REMOTS® Parameters 



3.1.1 Sediment Parameters 



Sediment parameters which are documented during REMOTS® analyses include grain 

 size modes and the presence of sedimentary features like mudclasts, shell layers, and surface 

 sediment bedforms. Finally, the presence and depth of sediment which appears to be 

 dredged material (rather than background sediment) is documented. 



Grain size ranges are estimated visually by overlaying a grain size scale on the image. 

 The grain size scale was prepared by photographing a series of Udden-Wentworth size 

 classes through the REMOTS® camera (SAIC 1985). A "major mode" (the most common 

 grain size) and the range of grain sizes present are identified. 



Ambient central Long Island Sound sediment consists generally of silt and clay 

 (>4 phi). The 1992 MQR survey indicated a similar distribution of grain sizes but included 

 a small fraction of coarser grained material (major mode 3-4 phi; Appendix). Overall, the 

 grain sizes reported for the 1992 survey were slightly coarser than both the CLIS reference 



Recolonization of the Mill-Quinnipiac River Disposal Mound (MQR): Results of a REMOTS® Survey, August 1992 



