comparison with future monitoring studies and to 
determine if a relationship exists between sediment 
contaminant concentrations and organism body burdens. 
2.0 METHODS 
2.1 Bathymetry and Navigation 
The precise navigation required for all field operations 
was provided by the SAIC Integrated Navigation and Data Acquisition 
System (INDAS). This system uses a Hewlett-Packard 9920 Series 
computer to collect position, depth, and time data for subsequent 
analysis as well as to provide real-time navigation. A display 
with the survey lanes and the real-time position of the vessel is 
provided to the helmsman. The positional information is recorded 
on magnetic disk every second along with depth and time. The 
computer system calculates accurate positions from the range data 
provided by the positioning system and is capable of converting 
from state plane coordinates in the Transverse Mercator system to 
Lambert or Mercator coordinates. 
Positions were determined to an accuracy of +3 meters 
from ranges provided by a Del Norte Trisponder System. Shore 
stations were established over known benchmarks used in previous 
surveys to allow accurate comparisons between the surveys. For the 
present surveys, shore stations were established in Connecticut at 
Millstone Point and New London Light. 
On 5 and 6 August 1985, a precision bathymetric survey 
was performed at the New London disposal site. The survey 
(designated NLON Master) consisted of 58 lanes, 3950 meters long, 
and spaced 50 meters apart. This resulted in a survey area 
covering the entire disposal site and extending 500 meters beyond 
its borders (Figure 2-1). Depth measurements collected during this 
survey were made using an Edo Western model 548E survey fathometer 
interfaced to an Edo model 261C Digitrak depth digitizer. The 
system was operated at a frequency of 24 KHz with accuracies to +/- 
20 cm in the depths encountered at this site. 
On 29 July 1985, a bathymetric survey was conducted at 
a location just outside the southwest boundary of the New London 
Disposal Site. This location had been identified as a stressed 
environment from analysis of REMOTS photos obtained earlier in July 
and mistakenly was considered a candidate area for disposal of 
dredged material. However, the fact that this area was outside 
the disposal site boundary disqualified it from further 
consideration as a disposal location. The bathymetric survey 
performed in this area consisted of 33 lanes 800 meters long spaced 
25 meters apart, covering an area 800 meters square (Figure 2-1); 
it was conducted with a Raytheon DE-719B Precision Survey 
Fathometer and a model SSD-100 depth digitizer. This system 
2 
