This functional type is usually associated with a shallow depth of 
bioturbation which results in a shallow redox boundary. In the 
absence of further disturbance, these early successional 
assemblages are eventually replaced by infaunal deposit feeders 
(Stage II). Typical Stage II species are shallow dwelling bivalves 
or tubicolous amphipods. Stage III taxa represent high-order 
successional stages typically found in low disturbance regimes. 
Many of these invertebrates feed at greater depth in a head-down 
orientation. The localized feeding activity results in distinctive 
excavations called feeding voids. These deep-dwelling infaunal 
taxa preferentially ingest the finer sediment particles and reject 
coarse-grained material. The bioturbational activities of these 
deposit feeders are responsible for aerating the sediment and 
causing the redox horizon to be located several centimeters below 
the sediment-water interface. In the retrograde transition of 
Stage III to Stage I, it is sometimes possible to recognize the 
presence of relict (i.e., collapsed and inactive) feeding voids. 
These end-member stages (Stages I and III) are easily 
recognized in REMOTS® photographs by the presence of dense 
assemblages of near-surface polychaetes and/or the presence of 
subsurface feeding voids; both types of assemblages may be present 
in the same photograph (classified as a Stage I on Stage III). 
REMOTS® Organism-Sediment Index 
A multi-parameter REMOTS® Organism-Sediment Index (OST) 
has been constructed to characterize habitat quality. Habitat 
quality is defined relative to two end-member standards. The 
lowest value is given to those bottom substrates which have low or 
no dissolved oxygen in the overlying bottom water, no apparent 
macrofaunal life, and methane gas present in the sediment. The OSI 
value for such a condition is minus 10. An aerobic bottom with a 
deeply depressed RPD, evidence of a mature macrofaunal assemblage, 
and no apparent methane gas bubbles at depth will have an OSI value 
of plus 11. The OSI is arrived at by summing a subset of indices 
(Tables 2—2))i- The OSI is an excellent parameter for mapping 
disturbance gradients in an area and documenting ecosystem recovery 
after disturbance (see Germano and Rhoads, 1984). 
2.4 Sediment Sampling and Analysis 
During the August 1985 survey, triplicate sediment 
samples were collected at five stations at the southwest corner of 
the survey area (see Figure 3-2) using a 0.1 m* Smith-McIntyre Grab 
Sampler. Four polycarbonate plastic core liners (6.5 cm ID) were 
pushed into the sediment grab sample and extracted; three cores 
were combined and placed into a bag for subsequent chemical 
analysis by the NED laboratory. The fourth core was bagged for 
physical analysis. All samples were kept cold and returned to the 
NED laboratory where they were stored at 4°C until analyzed. 
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