_5 



indicate a continued lack of a stable, benthic infaunal population over the entire FVP 

 mound. 



4.2.5 Organism-Sediment Indices (OSI) 



The multiparameter Organism-Sediment Index (OSI), used to characterize gradients 

 in habitat disturbance, can only be calculated at those stations where RPD and infaunal 

 successional stage are also determined. The OSI is calculated automatically by the image 

 analysis system after completion of all measurements from each REMOTS® image. Based 

 on the compiled results of REMOTS® surveys during the past 10 years, OSI values of less 

 than or equal to +6 are considered indicative of chronically stressed benthic habitats 

 and/or those which have experienced recent disturbance such as disposal (Rhoads and 

 Germano 1986). OSI values greater than +6 tend to represent relatively undisturbed 

 habitats or habitats that have experienced a long period of recovery relative to bottom areas 

 more recently disturbed. The replicate averaged OSI values over the disposal site ranged 

 from 2.3 to 7.5 and were indicative of a patchy benthic environment in varying states of 

 recovery (Figure 4-15). The NORWALK and SP mounds showed the most uniform values 

 of OSI. Values at the FVP mound ranged from 3 to 5 with one value of 9; this was at the 

 station with a Stage I on III community. 



Monitoring Surveys of the New Haven Capping Project, 1993-1994 



